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Mycobacterium bovis infection in humans and cats in same household, Texas, USA, 2012

Mycobacterium bovis infection of cats is exceedingly rare in regions where bovine tuberculosis is not endemic. We describe the diagnosis and clinical management of pulmonary M. bovis infection in 2 indoor-housed cats and their association with at least 1 M. bovis–infected human in Texas, USA, in September 2012.

Tuberculosis in humans and animals results from infection by bacilli within the Mycobacterium tuberculosis complex. Despite ≈99.95% genome sequence identity, M. bovis and M. tuberculosis exhibit distinct differences in host adaptation and susceptibility. M. bovis is the primary causative agent of bovine tuberculosis and infects a wider range of hosts than M. tuberculosis. In domestic cats, tuberculosis is caused primarily by infection with M. bovis or M. microti ; M. tuberculosis infection is less common. Before implementation of bovine tuberculosis control programs and wide-scale pasteurization of milk, alimentary tract disease was the most common form of tuberculosis in cats; today, lymphadenopathy and cutaneous forms are more common. Diagnosis is based on clinical examination, imaging, biopsy with histopathologic examination, culture of aspirates or tissues, and specific immune-based blood assays. Intradermal skin tests are generally unreliable for diagnosing tuberculosis in cats. Client history is critical for determining the possibility for exposure of the cat to the pathogen, and zoonotic aspects should be considered.

We describe the diagnosis and clinical management of pulmonary M. bovis infection in 2 indoor-housed cats and their association with at least 1 M. bovis–infected human in Texas, USA. In September 2012, a 5-year-old female domestic cat (cat Y) was seen by a veterinarian for dyspnea, tachypnea, hyporexia, and lethargy. She lived indoors with 4 other cats and their female owner. The vague history provided by cat Y’s owner indicated that, ≈11 months earlier, her husband had died of tuberculosis only 6 weeks after diagnosis and initiation of directly observed antimycobacterial therapy. At the time the husband’s tuberculosis was diagnosed, the woman was Mantoux-test negative; ≈2 months after his death, she converted to skin-test positive but had normal findings on thoracic radiographs. She was subsequently treated with antimycobacterial drugs. The woman also reported that, in June 2012, another cat in the household was euthanized after clinical signs developed that were similar to those of cat Y; no necropsy was performed. Additional pertinent history included relocation of the deceased husband from Mexico to Texas 15 years earlier, frequent contact with recent immigrants from Central America and Mexico, and consumption of unpasteurized Mexican cheeses.

Read more : http://wwwnc.cdc.gov/eid/article/21/3/14-0715_article

http://wwwnc.cdc.gov/eid/ Emerging Infectious Disease

http://wwwnc.cdc.gov/eid/article/21/3/14-0715_article Original web page at Emerging Infectious diseases

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* Rabies booster defends pets with out-of-date vaccination against the disease

A new study by Kansas State University veterinary diagnosticians finds that pets with out-of-date rabies vaccinations are very unlikely to develop the fatal disease if given a rabies booster immediately after exposure to the virus. The finding gives pet owners, veterinarians and public health officials new options when faced with the difficult situation of quarantining or even euthanizing a pet that has been exposed to the rabies virus, said Michael Moore, project manager of the Kanas State University Veterinary Diagnostic Laboratory. “This has the potential to save a lot of pets’ lives,” Moore said. “Our hope is that now animals with an out-of-date vaccination status that are exposed to rabies will be allowed to be handled the same as dogs and cats with up-to-date vaccinations. They will be given a booster and a 45-day observation at home.” Moore conducted the study with Rolan Davis, reference diagnostician of the Veterinary Diagnostic Lab; Derek Mosier, professor of diagnostic medicine and pathobiology; Christopher Vahl, assistant professor of statistics; and colleagues at the Statistical Intelligence Group LLC and Centers for Disease Control and Prevention. The findings appear in the Journal of the American Veterinary Medical Association study, “Comparison of anamnestic responses to rabies vaccination in dogs and cats with current and out-of-date vaccination status.” It is the first study to present scientific data for animals with out-of-date rabies vaccinations.

Each year the U.S. has around 6,000 documented cases of rabies, mostly in raccoons, skunks, bats and foxes. The disease is usually fatal for animals. Pets with out-of-date vaccinations that are exposed to the rabies virus are required to either stay in observed quarantine for six months — which can cost owners $5,000-$7,000 — or to be euthanized. “I get calls from a lot of people around the U.S. who are very sad because they had to euthanize their pet because they couldn’t afford the quarantine cost,” Moore said. “Even if an owner can afford the quarantine, they cannot see their pet for six months.” The study looked at 74 dogs and 33 cats with current and out-of-date rabies vaccinations. Most of the animals were one to two years out-of-date on their vaccines. A smaller segment was three to four years out-of-date.

Researchers studied the anamnestic antibody responses of the animals. They found that when an animal with an out-of-date vaccination was given a booster vaccination, the neutralizing antibodies in the animal’s blood rose, protecting the animal against exposure to the rabies virus. “Basically once an animal has been vaccinated, they can receive a booster if they are exposed to the rabies virus,” Moore said. “Then their chances for surviving that virus are very, very good.” The rabies booster is only effective if an animal has been given its initial rabies vaccination, Moore said. While conducting trials, researches also found that some manufacturers’ formulations for their one-year and three-year rabies vaccines were identical. In addition to the medical benefits, Moore said the findings might help clarify and shape the current guidelines for pets that are exposed to the rabies virus. “If you relate this to human health, humans are primed with an initial vaccination series and then have neutralizing antibodies checked from time to time,” Moore said. “If those antibodies fall below a certain level, we’re given a booster. While the vaccines are licensed for a certain number of years, the immune system doesn’t sync to a date on the calendar and shut down because it reached that particular date.”

http://www.sciencedaily.com/ Science Daily

http://www.sciencedaily.com/releases/2015/01/150126095321.htm Original web page at Science Daily

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* Cats claw their way into genetics

The cat genome is out of the bag, and has already helped to pinpoint a gene involved in kidney disease. Cats may have beaten dogs on the Internet but felines have been a rare breed in genetics labs compared with their canine counterparts. Now, at last, cats are clawing their way into genomics. At a meeting this week in San Diego, California, a close-knit group of geneticists unveiled the first results from an effort to sequence the genomes of 99 domestic cats. The work will benefit both humans and felines, the researchers say, by mapping the mutations underlying conditions that afflict the two species, such as kidney disease. “It’s a great time to be in cat genomics,” says William Murphy, a geneticist at Texas A&M University in College Station who is involved in the effort. Plummeting costs for DNA sequencing now make it possible to do genomics cheaply — and cat genomics, long under-funded compared with similar efforts in dogs, is benefiting, he says. “We’re finally at the point where we can do all sorts of things we wanted to do 5 or 10 years ago.” The first cat genome sequence — from an Abyssinian named Cinnamon — was reported in 2007. But the sequence contained significant gaps and errors, which slowed efforts to map genes. A high-quality version of Cinnamon’s genome was not published until late 2014. Domestic dogs, meanwhile, have become a darling of geneticists: their full genome was reported in 2005, and the sequence has been continually improved. Hundreds of genes underlying canine diseases and traits are estimated to have been discovered, compared with as few as a dozen for cats. The discrepancy can be traced back to the early 2000s. After the completion of the human, mouse and rat genomes, the US National Institutes of Health organized a commission to decide on their next target; the dog genome was selected for high-quality sequencing, whereas cats were put on hold. That got some cat geneticists’ backs up. “The truth is there were more powerful people interested in dogs,” says Stephen O’Brien, director of the Theodosius Dobzhansky Center for Genome Bioinformatics in St Petersburg, Russia, who led the initial cat-sequencing efforts. But canine researchers were able to make a compelling case. Pet dogs suffer from many of the same conditions as humans, from narcolepsy to arthritis. And the intensely inbred nature of dog breeds made it relatively easy to identify disease-causing genes: because there is little genetic variation within any particular breed, the genes that cause disease in affected individuals stand out. Dogs had other advantages, too. The existence of kennel clubs, which maintain ‘breed standards’ and are full of enthusiastic pet owners and veterinary surgeons, helped dog geneticists to recruit subjects for study. “Given the resources they had, they were discovering new genetic diseases in breeds almost daily,” says Niels Pedersen, a veterinary scientist at the University of California, Davis. “I would love to eradicate all genetic disease in cat breeds before we’re done.” In fact, both cats and dogs offer insights into human disease, including those associated with old age. In 2004, a team led by geneticist Leslie Lyons of the University of Missouri in Columbia (and owner of two female cats, Withers and Figaro) discovered that mutations that cause polycystic kidney disease — a major cause of renal failure in older individuals — occur in the same gene in humans and cats. Cat versions of type 2 diabetes, asthma, retinal atrophy and numerous other conditions have close similarities to human disease. Cats can also become infected with a virus that is closely related to HIV and experience symptoms similar to those of people with AIDS. In the hopes of speeding up the discovery of genes related to these conditions last year, Lyons launched the 99 Lives cat genome sequencing initiative, playfully hosted on a site called Lyons’ Den. She discussed the effort on 11 January at the Plant & Animal Genome conference in San Diego. Lyons’ team is cobbling together funding from anywhere it can find it. The researchers are asking private owners, breeders and even pet-food companies to donate the US$7,500 needed to sequence the genome of a single cat, which could be one of a donor’s choice. “Any cat can participate. Any owner can participate,” she says. All the data will be made public after the results are published. With the money raised so far, the team has sequenced the genomes of 56 cats, including fancy breeds such as Burmese; cats with specific diseases; and a kitten named Dragon and his parents Ares and Marcus — the hope is to use the feline trio to narrow down the genetic basis for traits they share, such as their silver, curly coats. Even Robert Wayne, a canine geneticist at the University of California, Los Angeles, agrees that Lyons’ effort is important. “I hope she raises money for it,” he says. Insights from cat genomics extend beyond disease. Razib Kahn, an evolutionary geneticist at the University of California, Davis, wants to use genome sequences to chart the domestication and spread of cats throughout the world, and to determine how different domestic and wild cats are genetically. “There’s always the question — are they domesticated at all?” he says. The 2014 publication that included Cinnamon’s genome already identified differences between domestic and wild cats, including genes expressed in the brain that are possibly linked to the docility of (some) house cats. “Wild cats will hand you your behind if you get next to them and domestic cats will sit on your lap,” O’Brien notes. Lyons is also keen to see genomics help felines. “I would love to eradicate all genetic disease in cat breeds before we’re done,” she says. Her team’s discovery of the cause of polycystic kidney disease has reduced its prevalence among Persians, by removing cats with the mutation from the breeding pool. Her lab is now developing drugs that could treat the terminal condition in cats — and perhaps in humans. But human health, Pedersen says, is not the only goal. “I’m in it, and Leslie’s in it, for the good of cats.”

Nature 517, 252–253 (15 January 2015) doi:10.1038/517252a See Editorial page 244

http://www.nature.com/news/index.html  Nature

http://www.nature.com/news/i-can-haz-genomes-cats-claw-their-way-into-genetics-1.16708  Original web page at Nature

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* Cat genome reveals clues to domestication​​

Cats and humans have shared the same households for at least 9,000 years, but we still know very little about how our feline friends became domesticated. An analysis of the cat genome led by researchers at Washington University School of Medicine in St. Louis reveals some surprising clues. he research appears Nov. 10 in the Proceedings of the National Academy of Sciences Early Edition. Cats have a relatively recent history of domestication compared with dogs; canines arose from wolves over 30,000 years ago. “Cats, unlike dogs, are really only semidomesticated,” said senior author Wes Warren, PhD, associate professor of genetics at The Genome Institute at Washington University​. “They only recently split off from wild cats, and some even still breed with their wild relatives. So we were surprised to find DNA evidence of their domestication.” One way scientists can understand the genetics of domestication is to look at what parts of the genome are altered in response to living together with humans, Warren added. The researchers compared the genomes of domestic cats and wild cats, finding specific regions of the domestic cat genome that differed significantly. The scientists found changes in the domestic cat’s genes that other studies have shown are involved in behaviors such as memory, fear and reward-seeking. These types of behaviors — particularly those when an animal seeks a reward — generally are thought to be important in the domestication process. “Humans most likely welcomed cats because they controlled rodents that consumed their grain harvests,” said Warren. “We hypothesized that humans would offer cats food as a reward to stick around.” This meant that certain cats that would normally prefer to lead solitary lives in the wild had an additional incentive to stay with humans. Over time, humans preferred to keep cats that were more docile. The cat genome sequencing project, funded by the National Human Genome Research Institute, part of the National Institutes of Health (NIH), began in 2007. The project’s initial goal was to study hereditary diseases in domestic cats, which are similar in some cases to those that afflict humans, including neurological disorders, and infectious and metabolic diseases. To obtain the high-quality reference genome needed for this research, the team sequenced a domestic female Abyssinian cat named Cinnamon. They chose this particular cat because they could trace its lineage back several generations. This cat’s family also had a particular degenerative eye disorder the researchers wanted to study.

To better understand characteristics of domestication, the researchers sequenced the genomes of select purebred domestic cats. Hallmarks of their domestication include features such as hair color, texture and patterns, as well as facial structure and how docile a cat is. Cats are bred for many of these types of characteristics. In fact, most modern breeds are the result of humans breeding cats for their favorite hair patterns. The team also looked at a breed called Birman, which has characteristic white paws. The researchers traced the white pattern to just two small changes in a gene associated with hair color. They found that this genetic signature appears in all Birmans, likely showing that humans selectively bred these cats for their white paws and that the change to their genome happened in a remarkably short period of time. The group also compared the cat genome with those of other mammals — including a tiger, cow, dog and human — to understand more about the genetics of cat biology. “We looked at the underlying genetics to understand why certain abilities to survive in the wild evolved in cats and other carnivores,” said Michael Montague, PhD, the study’s first author and a postdoctoral research associate at The Genome Institute. The differences they found in the cat genome help explain characteristics such as why cats are almost exclusively carnivorous and how their vision and sense of smell differ from other animals like dogs. To digest their fatty, meat-heavy meals, cats need genes to efficiently break down fats. The team found particular fat-metabolizing genes in carnivores such as cats and tigers that changed faster than can be explained by chance. This more rapid change generally means these genes provide some sort of digestive advantage to carnivores that only consume animal proteins. The researchers did not find such changes in the same genes of the cow and human, who eat more varied diets and would not need such enhancements. Cats also rely less on smell to hunt than dogs. So it is not surprising that the researchers found fewer genes for smell in cats than dogs. But they did find more genes related to an alternate form of smell that detects chemicals called pheromones, which allow cats to monitor their social environment, including seeking out the opposite sex. This ability is not as important to dogs, which tend to travel in packs. But it is crucial in cats, which are more solitary and may have more difficulty finding mates. Cats also have better hearing than most other carnivores, including an ability to hear in the ultrasonic range to better track prey. Their vision is also exceptional in low light. “Cats tend to be more active at dawn and dusk,” said Montague, “so they need to be able to detect movement in low light.” Accordingly, the team identified specific genes that likely evolved to expand cats’ hearing range and their vision in low light. Even though the genomes of domestic cats have changed little since their split from wild cats, the new work shows that it is still possible to see evidence of the species’ more recent domestication. “Using advanced genome sequencing technology, we were able to shed light on the genetic signatures of cats’ unique biology and survival skills,” said Warren. “And we were able to significantly jump start our knowledge about the evolution of cat domestication.”

http://www.sciencedaily.com/  Science Daily

http://www.sciencedaily.com/releases/2014/11/141110161042.htm  Original web page at Science Daily

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Cat dentals fill you with dread?

A survey published this year found that over 50% of final year veterinary students in the UK do not feel confident either in discussing orodental problems with clients or in performing a detailed examination of the oral cavity of their small animal patients. Once in practice, things don’t always improve and, anecdotally, it seems many vets dread feline dental procedures.

UK-based practitioners, Rachel Perry and Elise Robertson, who themselves felt woefully ill-prepared for feline dentistry as new graduates, have joined forces in an initiative to plug this educational gap. Harnessing their passion for cats and the expertise they have developed in small animal dentistry, they have coordinated a ground-breaking two-part special issue of the Journal of Feline Medicine and Surgery devoted to feline dentistry. The two Guest Editors have recruited a pool of international leaders in the disciplines of dentistry, maxillofacial surgery, medicine and anaesthesia to arm the practitioner with the knowledge and skill set required to provide ‘gold standard’ dental care for all feline patients. Articles, presented in the popular JFMS ‘Clinical Practice’ style, are highly practical and reader friendly, illustrated with stunning images, and supported with video and other online resources, including a feline dental chart. Part 1, the November 2014 issue describes a systematic approach to comprehensive oral examination in the cat; reviews the basics of taking and interpreting the intraoral radiographs that are so critical for proper diagnosis and therapy; presents a step-by-step photographic guide to familiarize the practitioner with feline oral anatomy and tooth extraction techniques; discusses best practice principles for ensuring a rapid return to a functional, pain- and inflammation-free occlusion for cats with traumatic dentoalveolar injuries. Part 2, to be published in January 2015, offers an equally valuable series of articles that will: systematically outline the nature of feline malocclusions typically seen in practice; address periodontal disease and tooth resorption, the two most common orodental complaints seen in practice; take a close look at the anaesthetic and analgesic protocol, an often-neglected aspect of feline dentistry. Contemporary dentistry is all about providing a comfortable patient that heals predictably and quickly alongside a satisfied and grateful client. ‘The days of ‘drilling out roots’ should be consigned to the history books,’ say the Guest Editors, ‘… alongside the days when cats didn’t require as much analgesia as dogs or were castrated in a Wellington boot!’

http://www.sciencedaily.com/  Science Daily

http://www.sciencedaily.com/releases/2014/10/141024111911.htm  Original web page at Science Daily

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* Cheetah menu: Wildlife instead of cattle

Scientists from the German Leibniz Institute for Zoo and Wildlife Research (IZW) can give the all-clear: in a recent study they showed that cheetahs primarily prefer wildlife on their menu. The cheetah is a vulnerable species that only exists on Namibia’s commercial farmland in large populations. Here, local farmers see cheetahs as a potential threat for their cattle.

The conflict is an old one: wherever there are carnivorous wild animals, farmers are concerned about their livestock. In Namibia, the concern refers to the possible threat from cheetahs on cattle. When farmers in Namibia are missing a bovine calf, cheetahs are regularly under suspicion — nowhere else in the world are there as many animals of this vulnerable species as on commercial farmland in Namibia. But the suspicion can rarely be confirmed without demur. In their recent study, scientists of the IZW investigated whether cattle is on top of the cheetahs’ menu. For this purpose they used an indirect method with which they were able to assess the diet over longer periods. “Traditionally, carnivore diet is determined by examining samples of fresh faeces. Faecal samples only provide a snapshot of the diet, based on the detected hair and bone samples of prey animals. One cannot therefore conclude which food items cheetahs devour in the long run,” explains Christian Voigt from the IZW.

Instead the scientists used samples of cheetah hair to determine the stable isotope ratios of carbon and nitrogen. Herbivores have different food webs. One is based on shrubs, trees and herbs whose photosynthesis contains intermediate products with three carbon atoms (C3). In contrast, grasses exhibit a C4 photosynthesis. These food webs can be differentiated with the help of the involved carbon isotopes. Herbivores typically only belong to one food web and the isotope ratio hence deposits in their body tissue. Small antelopes such as springbok or steenbok specialise on shrubs and herbs whereas the oryx antelope feeds on grass — just like the cattle. One step up in the food chain the isotope ratio of the prey transfers to its predator. The study shows that herbivores of the C4 food chain, to which cattle belong, are nearly irrelevant to the cheetah’s diet. Grazers are only occasionally considered as prey by males when they occur in groups of two or three animals. In this project the IZW scientists collaborated closely with the farmers. “We live with the farmers on their farmland and share our scientific results with them. In this way, we attain a very high acceptance,” emphasises Bettina Wachter. “The farmers passed on their experience in dealing with these big cats, as cheetahs cannot be simply lured with bait like many other carnivores,” she adds. This is owed to the fact that cheetahs only eat prey they brought down themselves. Thus, aided by the farmers, the scientists installed box traps at marking trees, which were hidden by thorn bushes except for a narrow passage. The only way to reach their tree is passing the trap. Once a cheetah is captured it is sedated and thoroughly examined: body length and weight are determined, samples of blood and hair are taken and then the scientists release the cheetah equipped with a tracking collar. “We conclude that the farmer’s problems are smaller than they had assumed before this study,” Voigt sums up. This study, published in the scientific online journal PLOS ONE, will contribute to the protection of cheetahs — but not in adversity to the interest of the farmers. “We understand their position. The concepts of species conversation always need to be balanced against the livelihood of humans,” says Wachter. The study is therefore an important mile stone to resolve the conflict between farmers and cheetahs.

http://www.sciencedaily.com/  Science Daily

http://www.sciencedaily.com/releases/2014/08/140827151707.htm  Original web page at Science Daily

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Nasty parasitic worm, common in wildlife, now infecting U. S. cats

When Cornell University veterinarians found half-foot-long worms living in their feline patients, they had discovered something new: The worms, Dracunculus insignis, had never before been seen in cats. “First Report of Dracunculus Insignis in Two Naturally Infected Cats from the Northeastern USA,” published in the February issue of the Journal of Feline Medicine and Surgery, document the first proof that this raccoon parasite can infect cats. The worms can grow to almost a foot long and must emerge from its host to lay eggs that hatch into larvae. It forms a blister-like protrusion in an extremity, such as a leg, from which it slowly emerges over the course of days to deposit its young into the water. Worms in the Dracunculus genus are well known in human medicine. D. insignis‘ sister worm, the waterborne Guinea worm, infected millions of humans around the world until eradication efforts beginning in the 1980s removed it from all but four countries — with only 148 cases reported in 2013. Other Dracunculus worms infect a host of other mammals — but Dranunculus insignis mainly infects raccoons and other wild mammals and, in rare cases, dogs. It does not infect humans. The cats that contracted the Dranunculus insignis worms likely ingested the parasites by drinking unfiltered water or by hunting frogs,” said Araceli Lucio-Forster, a Cornell veterinary researcher and the paper’s lead author.

It takes a year from the time a mammal ingests the worm until the females are ready to migrate to an extremity and start the cycle anew. While the worms do little direct harm beyond creating shallow ulcers in the skin, secondary infections and painful inflammatory responses may result from the worm’s emergence from the host. There are no drugs to treat a D. insignis infection — the worms must be removed surgically. “Although rare in cats, this worm may be common in wildlife and the only way to protect animals from it is to keep them from drinking unfiltered water and from hunting — in other words, keep them indoors,” said Lucio-Forster.

http://www.sciencedaily.com/  Science Daily

March 18, 2014

http://www.sciencedaily.com/releases/2014/02/140227163833.htm  Original web page at Science Daily

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Humans responsible for 62% of cougar deaths in re-established population

The reintroduction of mountain lions across the mid-western United States has made species management an urgent area of research for conservationists. A report in the Wildlife Society Bulletin explores the fatal cost of human interaction with cougars and asks what state agencies can do to protect both species. Cougars (Puma concolor) are slowly recolonizing their historic habitats, including the Black Hills of South Dakota, but since they’ve been away, the land has become crossed with roads and home to many human communities. “The cougar population in the Black Hills Region is unique, as it is separated by 180 km of prairie and agricultural land from the nearest breeding population,” said Dr. David Thompson from South Dakota State University. “Yet, it is a viable population, which is safe from hunting and it has increased in recent decades through natural immigration.” The authors studied 31 cougars, captured between 1999 and 2005. Over the course of 1,570 days, 12 mortalities were recorded. Despite being protected from hunting nearly 62% of cougar deaths were attributed to human influences. A further 85 dead cougars were analyzed during the study, with collisions being the most common cause of death. Snaring and illegal hunting were also identified as causes. “Our work evaluated the types of mortality that occur in a naturally re-established cougar population on the eastern edge of the current range of the species in North America,” concluded Thompson. “Our findings will be valuable to areas experiencing re-colonization of the species as well as providing insight into regions where human populations overlap with cougars from a management perspective.”

http://www.sciencedaily.com/  Science Daily

March 18, 2014

http://www.sciencedaily.com/releases/2014/03/140303084258.htm  Original web page at Science Daily

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Cat parasite found in western Arctic Beluga deemed infectious

University of British Columbia scientists have found for the first time an infectious form of the cat parasite Toxoplasma gondii in western Arctic Beluga, prompting a health advisory to the Inuit people who eat whale meat. The same team also discovered a new strain of the parasite, previously sequestered in the icy north, that is responsible for killing 406 grey seals in the north Atlantic in 2012. Presenting their findings the 2014 Annual Meeting of the American Association for the Advancement of Science (AAAS), Michael Grigg and Stephen Raverty from UBC’s Marine Mammal Research Unit say that the “big thaw” occurring in the Arctic is allowing never-before-seen movement of pathogens between the Arctic and the lower latitudes. “Ice is a major eco-barrier for pathogens,” says Michael Grigg, a molecular parasitologist with the U.S. National Institutes of Health and an adjunct professor at UBC. “What we’re seeing with the big thaw is the liberation of pathogens gaining access to vulnerable new hosts and wreaking havoc.” Toxoplasmosis, also known as kitty litter disease, is the leading cause of infectious blindness in humans and can be fatal to fetuses and to people and animals with compromised immune systems.

“Belugas are not only an integral part of Inuit culture and folklore, but also a major staple of the traditional diet. Hunters and community members are very concerned about food safety and security,” says Raverty, a veterinary pathologist with the B.C. Ministry of Agriculture and Lands’ Animal Health Centre and an adjunct professor at UBC. Raverty has led the systematic sampling and screening of hunter-harvested Beluga for 14 years. Grigg has also identified the culprit of the 2012 grey seal die-off as a new strain of Sarcocystis. While not harmful to humans, the Arctic parasite, which was named Sarcocystis pinnipedi at the AAAS meeting today, has now killed an endangered Steller sea lion, seals, Hawaiian monk seals, walruses, polar and grizzly bears in Alaska and as far south as British Columbia.

http://www.sciencedaily.com/ Science Daily March 4, 2014

http://www.sciencedaily.com/releases/2014/02/140213153532.htm  Original web page at Science Daily

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Cat domestication traced to Chinese farmers 5,300 years ago

Five-thousand years before it was immortalized in a British nursery rhyme, the cat that caught the rat that ate the malt was doing just fine living alongside farmers in the ancient Chinese village of Quanhucun, a forthcoming study in the Proceedings of the National Academy of Sciences has confirmed. “At least three different lines of scientific inquiry allow us to tell a story about cat domestication that is reminiscent of the old ‘house that Jack built’ nursery rhyme,” said study co-author Fiona Marshall, PhD, a professor of archaeology in Arts & Sciences at Washington University in St. Louis. “Our data suggest that cats were attracted to ancient farming villages by small animals, such as rodents that were living on the grain that the farmers grew, ate and stored.” Set for early online publication in PNAS during the week of Dec. 16, the study provides the first direct evidence for the processes of cat domestication. “Results of this study show that the village of Quanhucun was a source of food for the cats 5,300 years ago, and the relationship between humans and cats was commensal, or advantageous for the cats,” Marshall said. “Even if these cats were not yet domesticated, our evidence confirms that they lived in close proximity to farmers, and that the relationship had mutual benefits.”

Cat remains rarely are found in ancient archaeological sites, and little is known about how they were domesticated. Cats were thought to have first been domesticated in ancient Egypt, where they were kept some 4,000 years ago, but more recent research suggests close relations with humans may have occurred much earlier, including the discovery of a wild cat buried with a human nearly 10,000 years ago in Cyprus. While it often has been argued that cats were attracted to rodents and other food in early farming villages and domesticated themselves, there has been little evidence for this theory. The evidence for this study is derived from research in China led by Yaowu Hu and colleagues at the Chinese Academy of Sciences. Hu and his team analyzed eight bones from at least two cats excavated from the site. Using radiocarbon dating and isotopic analyses of carbon and nitrogen traces in the bones of cats, dogs, deer and other wildlife unearthed near Quanhucan, the research team demonstrated how a breed of once-wild cats carved a niche for themselves in a society that thrived on the widespread cultivation of the grain millet. Carbon isotopes indicate that rodents, domestic dogs and pigs from the ancient village were eating millet, but deer were not. Carbon and nitrogen isotopes show that cats were preying on animals that lived on farmed millet, probably rodents. At the same time, an ancient rodent burrow into a storage pit and the rodent-proof design of grain storage pots indicate that farmers had problems with rodents in the grain stores.

Other clues gleaned from the Quanhucun food web suggest the relationship between cats and humans had begun to grow closer. One of the cats was aged, showing that it survived well in the village. Another ate fewer animals and more millet than expected, suggesting that it scavenged human food or was fed. Recent DNA studies suggest that most of the estimated 600 million domestic cats now living around the globe are descendants most directly of the Near Eastern Wildcat, one of the five Felis sylvestris lybica wildcat subspecies still found around the Old World. Marshall, an expert on animal domestication, said there currently is no DNA evidence to show whether the cats found at Quanhucun are descendants of the Near Eastern Wildcat, a subspecies not native to the area. If the Quanhucun cats turn out to be close descendents of the Near Eastern strain, it would suggest they were domesticated elsewhere and later introduced to the region. “We do not yet know whether these cats came to China from the Near East, whether they interbred with Chinese wild-cat species, or even whether cats from China played a previously unsuspected role in domestication,” Marshall said. This question is now being pursued by researchers based in China and in France.

Science Daily
January 7, 2014

Original web page at Science Daily

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Fossil of new big cat species discovered: Oldest ever found

The oldest big cat fossil ever found — which fills in a significant gap in the fossil record — was discovered on a paleontological dig in Tibet, scientists announced today. A skull from the new species, named Panthera blytheae, was excavated and described by a team led by Jack Tseng — a PhD student at the USC Dornsife College of Letters, Arts and Sciences at the time of the discovery, and now a postdoctoral fellow at the American Museum of Natural History (AMNH) in New York. “This find suggests that big cats have a deeper evolutionary origin than previously suspected,” Tseng said. The announcement was made in a scientific paper published by the Proceedings of the Royal Society B: Biological Sciences, on Nov. 13. DNA evidence suggests that the so-called “big cats” — the Pantherinae subfamily, including lions, jaguars, tigers, leopards, snow leopards, and clouded leopards — diverged from their nearest evolutionary cousins, Felinae (which includes cougars, lynxes, and domestic cats), about 6.37 million years ago. However, the oldest fossils of big cats previously found are tooth fragments uncovered at Laetoli in Tanzania (the famed hominid site excavated by Mary Leakey in the 1970s), dating to just 3.6 million years ago. Using magnetostratigraphy — dating fossils based on the distinctive patterns of reversals in Earth’s magnetic field, which are recorded in layers of rock — Tseng and his team were able to estimate the age of the skull at between 4.10 and 5.95 million years old. The new cat takes its name from Blythe, the snow-leopard-loving daughter of Paul and Heather Haaga, who are avid supporters of the Natural History Museum of Los Angeles County. The find not only challenges previous suppositions about the evolution of big cats, it also helps place that evolution in a geographical context. The find occurs in a region that overlaps the majority of current big cat habitats, and suggests that the group evolved in central Asia and spread outward. In addition, recent estimates suggested that the genus Panthera (lions, tigers, leopards, jaguars, and snow leopards) did not split from genus Neofelis (clouded leopards) until 3.72 million years ago — which the new find disproves. Tseng, his wife Juan Liu, and Takeuchi discovered the skull in 2010 while scouting in the remote border region between Pakistan and China — an area that takes a bumpy seven-day car ride to reach from Beijing. Liu found over one hundred bones that were likely deposited by a river eroding out of a cliff. There, below the antelope limbs and jaws, was the crushed — but largely complete — remains of the skull. “It was just lodged in the middle of all that mess,” Tseng said. For the past three years, Tseng and his team have used both anatomical and DNA data to determine that the skull does, in fact, represent a new species.

Science Daily
December 10, 2013

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Ancient cat may reshape feline family tree

The world’s first big cats may have arisen millions of years earlier than previously thought. That’s the conclusion researchers are drawing from a newly discovered species of feline, similar to today’s snow leopard, that lived in the ancient Himalayas. Though the creature doesn’t have any living descendants, it may force researchers to rethink the cat family tree. Much of our knowledge about the origin of ancient cats comes from the DNA of living ones. In an extensive 2006 study, researchers made a rough sketch of the evolutionary history of pantherines, the lineage that includes today’s tigers, lions, leopards, and jaguars. They used overlap between the DNA sequences of modern species to backtrack to when various cat lineages likely diverged. According to this picture, the first pantherine evolved from an unknown ancestor, probably living in Central Asia, 10 million to 11 million years ago. Later research suggested that the big cat lineage didn’t start branching into other species—ancestors of modern tigers, for example—until roughly 2 million years ago. But paleontologists have been reluctant to accept this DNA-based picture, says Julie Meachen, a vertebrate paleontologist at Des Moines University who specializes in carnivores. “We want to actually see the fossil,” she says. Until now, the oldest pantherine fossils were 3.8-million-year-old teeth and jaw and skull fragments found in East Africa, not Asia.

For 8 years, vertebrate paleontologist Z. Jack Tseng of the American Museum of Natural History in New York City has been part of a team searching for fossils in the cold, dry Tibetan Plateau—a landscape he says is reminiscent of South Dakota’s Badlands. In 2010, the group discovered a fossil-rich spot in an area called Zanda Basin: 120 fragments from more than a dozen mammal species were crammed into about one square meter of ground. Among the limbs of extinct antelopes, horses, and rhinos, the researchers turned up a few rare fragments—a skull, several jaws, and teeth—that seemed to belong to a species of cat. Based on the area’s geography, they suspected it would be a relative of the uniquely cold-adapted snow leopard. They soon discovered that the fragments came from at least three individuals of a never-before-seen species dating back 4 million to 6 million years—older than the oldest African find. In a paper published online today in the Proceedings of the Royal Society B, Tseng and his colleagues introduce Panthera blytheae, named for the daughter of avid supporters of the Natural History Museum of Los Angeles County, with which several of the authors are affiliated. The creature, which they believe to be a sister species of the snow leopard, was a dwarf compared with modern lions and tigers. With an estimated weight of about 20 kilograms, it was roughly 10% smaller than the snow leopard. But it appears to share some of that cold-dwelling carnivore’s features, such as a wide forehead, believed to represent an expanded sinus cavity where frigid Himalayan air warmed up with each inhale.

The Himalayan finding is “a nice surprise,” says Andrew Kitchener, a mammalogist at the National Museum of Scotland in Edinburgh whose team uncovered a primitive member of the tiger lineage in China in 2011. “It’s given us a new part of the world to look at for the evolution of the big cat lineage.” The group constructed a new evolutionary tree by combining physical features of the blytheae bones with features of other fossils, plus DNA data from living species. Its analysis pushes back the emergence of big cats to roughly 16.4 million years ago. This number has a wide margin of error, Tseng cautions. But more importantly, he says, by 6 million years ago (when previous research claimed big cats had not yet diversified), at least three separate lineages likely roamed Asia: one containing P. blytheae and the snow leopard, one containing the clouded leopard, and another leading to the modern tiger. (The ancestors of jaguars and lions probably arose later.) The team suggests that when shifting tectonic plates forced the Himalayas upward, many mammals—including, according to their new tree, the emerging pantherines—diversified in this snowy refuge. Some species then spread out across the continent during the Pleistocene ice age. The research gives new support to the idea that the first big cats radiated from Central Asia, says William Murphy, a molecular geneticist at Texas A&M University in College Station and an author on the 2006 study. But he is skeptical of the claim that P. blytheae is a sister species of the snow leopard. With only a few pieces of the skeleton, the group determined this relationship using a limited number of subtle features of the teeth, skull, and jaw, he says, which may not be reliable.

“It’s possible that this fossil species might have a deeper ancestry in the Panthera tree,” he says, in which case they weren’t a part of the more recent diversification that Tseng and his colleagues link to the rising Himalayas. Rather than being nestled among the lineages that led to modern-day cats, it may have been an outlier, which happened to evolve snow leopard-esque features to survive at the top of the world. If P. blytheae actually belongs somewhere else on the tree, this would change the estimates for important splits in the big cat lineage. The only way to clear up these relationships: Dig up more complete fossils.

ScienceNow
November 26, 2013

Original web page at ScienceNow

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Australian cats and foxes may not deserve their bad rep

Foxes and feral cats are wildly unpopular among Australian conservationists. The two animals are infamous for killing off the continent’s native species, and they’ve been the targets of numerous government-backed eradication campaigns. But new research suggests that on Australian islands, these predators help control an even more destructive one: the black rat. As a result, eliminating cats and foxes could actually leave native mammals more vulnerable to predation, competition, and ultimately extinction. Australia is ground zero for the modern biodiversity crisis. The continent has suffered more than a quarter of all recent mammal extinctions, and many other native species survive only as small populations on one or more of the country’s thousands of islands. While habitat destruction has caused some extinctions, cats, foxes, and rats introduced around 1800 by British sailors have also played a major role, decimating native animals like bilbies and bandicoots—both small, ratlike marsupials found only in Australia. All of this has given large, nonnative predators like cats and foxes a bad name. “We hate them,” biologist Emily Hanna of the Australian National University in Canberra declared here last month at the International Congress for Conservation Biology.

But to plan successful eradication campaigns, scientists must first understand how introduced predators interact with native fauna and with each other. For instance, cats and foxes are infamous for hunting birds and other wildlife, but they can also control rats, which are themselves ferocious killers of and competitors with native animals like the bandicoot. To date, few studies have looked at which type of predator is actually most likely to drive native animals extinct. To determine which island invaders were doing the most damage, Hanna and her research adviser Marcel Cardillo created and analyzed what she calls a “ridiculously large” database comprising 934 living and extinct populations of 107 mammal species on 323 Australian islands between the early 1800s and today. For each island, the researchers recorded the presence or absence of various native mammals, and of rats, cats, foxes, and wild dogs known as dingoes, which some scientists believe help control invasive predators. The researchers also included other factors that might affect extinction risk, such as the size of the island and distance from the mainland. (Ecologists have found that island populations close to continents are more easily replenished, while more distant populations more easily go extinct.) Hanna then analyzed these data to find which factors most often correlated with native mammal extinctions.

The study yielded some surprising results: Native mammals were most likely to die off on islands that had rats, but not cats, foxes, or dingoes. Extinction rates on such islands ranged from 15% to 30%, but when cats, foxes, or dingoes were present, the rates plummeted to just over 10%—not much higher than on islands without any introduced predators, the scientists reported at the meeting and online this month in the journal Global Ecology and Biogeography. The scientists also found that native mammals fared only slightly worse on islands with cats than on islands without them. Moreover, the presence of foxes and dingoes on islands seemed to give native species a slight overall boost. “I was really surprised,” Hanna says. “I thought I’d made a big mistake.” Hanna and Cardillo also found that rats’ impact was most pronounced on small mammals—those weighing less than 2.7 kilograms—although the scientists are unsure how much of this influence was due to direct predation as opposed to competition for food and other resources or disease spread. Rats also had the greatest effect on islands within 2.1 kilometers of mainland Australia.

The study includes “a very nice, large data set, and a very well-constructed and complete analysis of the problem,” says Phillip Cassey, an ecologist at the University of Adelaide Environment Institute. The results suggest that managers may need to simultaneously eliminate more than one predator to save rare animals from extinction, he adds; eradication efforts frequently focus on only one species. When it comes to planning such eradication campaigns on limited budgets, Cassey says, “analyses like Hanna’s, which can assist in prioritization, are going to be really important.” Despite the apparent benefit of cats and foxes, Hanna does not advocate introducing the animals to islands that don’t already have them. But she says her results do raise questions about the strategy of trying to kill top predators off while ignoring rats. She now hopes to study whether her results also apply to birds and other groups of native species and to other predators.

ScienceNow
September 17, 2013

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Parasites in cat feces: Potential public health problem?

Each year in the United States, cats deposit about 1.2 million metric tons of feces into the environment, and that poop is carrying with it what may be a vast and underappreciated public health problem, say scientists July 9 in the journal Trends in Parasitology, a Cell Press publication. Some of that poop is laden with an infectious parasite known as Toxoplasma gondii, a protozoan that has recently caused toxoplasmosis epidemics in otherwise healthy people, not just in pregnant women or people with immune deficiencies. Additional concerns have been raised by studies linking T. gondii to schizophrenia, obsessive-compulsive disorder, rheumatoid arthritis, brain cancer, and even to kids’ trouble in school. “The accumulation of Toxoplasma gondii oocysts, found in cat feces, may be a much bigger problem than we realize because of their apparent long life and their association with some diseases,” said E. Fuller Torrey, who directs the Stanley Medical Research Institute. He calls for better control of the cat population, especially feral cats, and more research. Surveys have shown that our backyards and communities may harbor three to 400 oocysts per square foot or more in places where cats frequently leave deposits. Each and every one of those oocysts has the potential to cause an infection.

As for the cats, they typically become infected upon hunting and eating an infected bird, mouse, or other small mammal. Then, they spread oocysts around into the soil, grass, water, and elsewhere. For cat owners, there is little need to worry if your cats stay indoors, Torrey says. If your feline friend (or your neighbors’) does spend time outside, take care with litter boxes, keep sandboxes covered, and wear gloves when gardening. One estimate shows that the dirt under ones fingernails could harbor up to 100 T. gondii oocysts. Torrey and coauthor Robert Yolken of Johns Hopkins University Medical Center recommend extra care with young children, who may be at the greatest risk. But, at this point, there are still many unknowns. Is it worth getting tested? “No,” Torrey says, except perhaps in the case of pregnant women. “Fifteen percent of us have antibodies, including me.” And, he adds, someone who tests positive at one point in time can later test negative.

Science Daily
July 23, 2013

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Wild cheetah accelerate fast and reach speeds of up to 58 miles per hour during a hunt

Researchers at the Royal Veterinary College have captured the first detailed information on the hunting dynamics of the wild cheetah in its natural habitat. Using an innovative GPS and motion sensing collar that they designed, Professor Alan Wilson and his team were able to record remarkable speeds of up to 58 miles per hour (or 93 kilometers per hour). The results, from the team at the Royal Veterinary College’s Structure & Motion Laboratory, are published June 13, 2013 in Nature. To date, measurements of cheetah locomotion mechanics have only been made on captive animals chasing a lure in a straight line, with few studies eliciting speeds faster than racing greyhounds. For wild cheetahs, estimates of speed have only ever been made from direct observation or film, in open habitat and during daylight hours. The team, led by Professor Wilson, developed a tracking collar equipped with a GPS module and electronic motion sensors (accelerometers, magnetometers, gyroscopes) capable of delivering processed position and velocity data and sensitive to the animal’s movements. The collar was powered by a combination of solar cells, rechargeable and non-rechargeable batteries. Collar software monitored the accelerometers to create activity summaries and detect the brief hunting events and adapted collar operation to battery voltages and time of day, meaning that researchers only captured data during a hunt. Overall, researchers recorded data from 367 runs by three female and two male adult cheetahs over 17 months. An episode of feeding after a run indicated hunting success, and was identified in the activity data by consistent, low-magnitude acceleration.

Data revealed that wild cheetah runs started with a period of acceleration, either from stationary or slow movement (presumably stalking) up to high speed. The cheetahs then decelerated and manoeuvred before prey capture. About one-third of runs involved more than one period of sustained acceleration. In successful hunts, there was often a burst of accelerometer data after the speed returned to zero, interpreted as the cheetah subduing the prey — in this case mainly Impala, which made up 75% of their diet. The average run distance was 173m. The longest runs recorded by each cheetah ranged from 407 to 559 m and the mean run frequency was 1.3 times per day, so, even if some hunts were missed, high speed locomotion only accounted for a small fraction of the 6,040-m average daily total distance covered by the cheetahs. The team was also able to identify factors that make up a successful hunt. Successful hunts involved greater deceleration on average, but there was no significant difference in peak acceleration, distance travelled, number of turns, or total turn angle. This indicates that outcome was determined in the final stages of a hunt rather than hunts being abandoned early to save energy or reduce risk of injury, and the higher deceleration values may reflect actual prey capture.

The greatest acceleration and deceleration values were almost double values published for polo horses and exceeded the accelerations reported for greyhounds at the start of a race. The acceleration power for the cheetahs was four times higher than that achieved by Usain Bolt during his world record 100 metres run, about double that for racing greyhounds and more than three times higher than polo horses in competition. Grip and manoeuvrability, rather than top speed, were shown to be key to hunting success. Hunts involved considerable manoeuvring, with maximum lateral (centripetal) accelerations often exceeding 13ms-2 at speeds less than 17ms-1 (polo horses achieve 6ms-2). Professor Alan Wilson, said: “Although the cheetah is recognised as the fastest land animal, very little is known about other aspects of its notable athleticism, particularly when hunting in the wild. Our technology allowed us to capture what to our knowledge is the first detailed locomotor information on the hunting dynamics of a large cursorial predator in its natural habitat and as a result we were able to record some of the highest measured values for lateral and forward acceleration, deceleration and body mass. “In the future, equivalent data for other wild cursorial species would enhance what we know about natural speed, agility and endurance, and provide detailed information on ranging behaviour in the wild. For example, information on habitat selection by endangered species detailing where animals are commuting, hunting and resting would be informative when attempting to evaluate wildlife-protected areas.” The cheetahs used in this study were part of a continuing study by Botswana Predator Conservation Trust in the Okavango Delta region of Northern Botswana.

Science Daily
July 9, 2013

Original web page at Science Daily

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Museum find proves exotic ‘big cat’ prowled British countryside a century ago

The rediscovery of a mystery animal in a museum’s underground storeroom proves that a non-native ‘big cat’ prowled the British countryside at the turn of the last century. The animal’s skeleton and mounted skin was analysed by a multi-disciplinary team of Durham University scientists and fellow researchers at Bristol, Southampton and Aberystwyth universities and found to be a Canadian lynx — a carnivorous predator more than twice the size of a domestic cat. The research, published today in the academic journal Historical Biology, establishes the animal as the earliest example of an “alien big cat” at large in the British countryside. The research team say this provides further evidence for debunking a popular hypothesis that wild cats entered the British countryside following the introduction of the 1976 Wild Animals Act. The Act was introduced to deal with an increasing fashion for exotic — and potentially dangerous — pets. The academics believe such feral “British big cats” as they are known, may have lived in the wild much earlier, through escapes and even deliberate release. There is no evidence that such animals have been able to breed in the wild.

The study of the Canadian lynx, rediscovered by research team member Max Blake among hundreds of thousands of specimens at Bristol Museum and Art Gallery, details records unearthed at the museum which showed the animal had originally been mislabelled by Edwardian curators in 1903 as a Eurasian lynx — a close relative of the Canadian lynx. The records also showed that the lynx was shot by a landowner in the Devon countryside in the early 1900s, after it killed two dogs. “This Edwardian feral lynx provides concrete evidence that although rare, exotic felids have occasionally been part of British fauna for more than a century,” said lead researcher, Dr Ross Barnett of Durham University’s Department of Archaeology. “The animal remains are significant in representing the first historic big cat from Britain.” Co-author Dr Darren Naish, from the University of Southampton, added: “There have been enough sightings of exotic big cats which substantially pre-date 1976 to cast doubt on the idea that one piece of legislation made in 1976 explains all releases of these animals in the UK. “It seems more likely that escapes and releases have occurred throughout history, and that this continual presence of aliens explains the ‘British big cat’ phenomenon.”

The researchers point out in their paper that Eurasian lynxes existed in the wild in Britain many hundreds of years ago, but had almost certainly become extinct by the 7th century. Laboratory analysis of the Bristol specimen’s bones and teeth established it had been kept in captivity long enough to develop severe tooth loss and plaque before it either escaped or was deliberately released into the wild. Ancient DNA analysis of hair from the lynx proved inconclusive, possibly due to chemicals applied to the pelt during taxidermy. Julie Finch, head of Bristol’s Museums, Galleries & Archives, said: “Bristol Museum, Galleries and Archives were pleased to be a part of this ground-breaking research, which not only highlights the importance of our science collections, it establishes the pedigree of our 100-year old Lynx and adds to our knowledge and understanding of ‘big cats’ in the UK. “Our museum collections are extensive and caring for them requires the considerable skills of our collections officers. We have an amazing collection of taxidermy animals on display and we welcome museum visitors to come along, to take a closer look and discover more about the natural world.” Dr Greger Larson, a member of the research team from Durham University and an expert in the migration of animals, said: “Every few years there is another claim that big cats are living wild in Britain, but none of these claims have been substantiated. It seems that big cats are to England what the Loch Ness Monster is to Scotland. “By applying a robust scientific methodology, this study conclusively demonstrates that at least one big cat did roam Britain as early as the Edwardian era, and suggests that additional claims need to be subjected to this level of scrutiny.” The lynx is now on public display at Bristol museum.

Science Daily
May 14, 2013

Original web page at Science Daily

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Study of pumas in Santa Cruz Mountains documents impact of predator/human interaction

In the first published results of more than three years of tracking mountain lions in the Santa Cruz Mountains, UC Santa Cruz researchers document how human development affects the predators’ habits. In findings published April 17 in the online journal PLOS ONE, UCSC associate professor of environmental studies Chris Wilmers and colleagues with the UC Santa Cruz Puma Project describe tracking 20 lions over 6,600 square miles for three years. Researchers are trying to understand how habitat fragmentation influences the physiology, behavior, ecology, and conservation of pumas in the Santa Cruz Mountains. “Depending on their behavior, animals respond very differently to human development,” Wilmers said. Lions are “totally willing to brave rural neighborhoods, but when it comes to reproductive behavior and denning they need more seclusion.” The large predators living relatively close to a metropolitan area require a buffer from human development at least four times larger for reproductive behaviors than for other activities such as moving and feeding. “In addition, pumas give a wider berth to types of human development that provide a more consistent source of human interface,” such as neighborhoods, than they do in places where human presence is more intermittent, as with major roads or highways, the authors write.

Wilmers and his team, which includes graduate students, and a dog tracking team working with the California Department of Fish and Wildlife, have captured 37 lions to date. Twenty-12 females and eight males-were closely followed between 2008 and 2011. Once captured and anesthetized, the lions’ sex was determined, they were weighed, measured, fit with an ear tag and a collar with a GPS transmitter. The collars, developed, in part, by an interdisciplinary team at UCSC, including wildlife biologists and engineers, transmit location data every four hours. Researchers are able to track the lions’ movements and calculate locations of feeding sites, communication spots, and dens. Pumas communicate with scent markings known as “scrapes” where they scrape leaves or duff into a pile then urinate on it. Males typically make the scrapes, advertising their presence and availability. Females visit scrapes when looking for mates. The Puma Project team set up and monitored remote cameras at 44 scrape locations and documented males and females, which confirmed GPS data from the pumas’ collars. Researchers also found 10 den sites belonging to 10 different female lions. They visited 224 “GPS clusters” where activities suggested a feeding site, and located prey remains at 115 sites. Wilmers said the research is helping identify corridors where pumas typically travel between areas of high-quality habitat. This includes neighborhoods where females often are willing to explore for food for their fast-growing brood.

Brushes with humans have resulted in casualties when lions were struck by cars or caught raiding livestock. One male known as 16M was shown to have crossed busy Highway 17 between Scotts Valley and Los Gatos 31 times. He was hit and badly injured in November 2010 and recently shot and killed after attacking goats. A female, 18F, who may have been 16M’s mate, was killed in 2011 crossing the winding highway. Eight of the 11 pumas that died during the study were killed when caught attacking domestic livestock. Wilmers advised owners of goats or other livestock to consider keeping them in a “fully-enclosed mountain lion-proof structure.” While Wilmers advised people to proceed with caution in any known mountain lion roaming grounds he said humans need not panic about the presence of mountain lions. The study’s conservation goals are meant to help lions survive in the midst of rapidly growing human development by building awareness of lions’ behavior and providing safe transit opportunities under or over major highways.

Science Daily
April 29, 2013

Original web page at Science Daily

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Cryopreservation: A chance for highly endangered mammals

Oocytes of lions, tigers and other cat species survive the preservation in liquid nitrogen. Scientists of the Leibniz Institute for Zoo and Wildlife Research (IZW) in Berlin succeeded in carrying out cryopreservation of felid ovary cortex. “We have successfully frozen and thawed oocytes in the ovary cortex of different cat species at minus 196 degrees Celsius. This freezing process and the storage of living cellular material in liquid nitrogen is called cryopreservation,” said Caterina Wiedemann, doctoral candidate at the IZW. The ovarian cortex is regarded as a reservoir of reproductive cells. It contains thousands of immature oocytes. Successful cryopreservation of ovarian tissue of wild cats is therefore a key element for the establishment of genome resource banks, an important tool for the preservation of genetic diversity. All felid species except for the domestic cats are listed on the Red List for endangered species of the International Union for Conservation of Nature (IUCN). Taking a freezing procedure developed in human medicine as their model, scientists at the Department of Reproduction Biology of the IZW developed a method for cryopreserving the ovarian cortex of different cat species. In the original procedure, ovarian tissue of women who suffer from cancer is removed to avoid its damage by chemotherapy or radiotherapy. After successful tumor treatment the tissue is re-transplanted so that the normal female cycle, including fertility, can be restored. In the meantime, the tissue is conserved in liquid nitrogen. The IZW adapted this method to preserve female germ cells from feline species.

The particular challenge in the cryopreservation of ovarian cortex tissue comes from the fact that the cells are embedded in a very complex system. Ovarian cortex is composed of immature oocytes surrounded by small somatic cells, different connective tissue and blood vessel cells. In addition, the cellular properties of every species are unique, thus it not possible to develop a common freezing procedure applicable to all species. For the cat cells, the scientists of the IZW worked out a “slow” freezing protocol. The cortex was dissected into evenly chopped pieces, each 2 mm in diameter. The cellular material was frozen at a speed of 0.3 degrees per minute. Ethylene glycol and saccharose were used as cryoprotectant agents. To demonstrate their survival after thawing the ovaries, the cortex was cultured in a medium for up to 14 days before and after the freezing. The IZW owns the genome resource bank „Arche,” which contains, inter alia, a variety of sperm samples of various wildlife species. The newly developed cryopreservation method will substantially improve the future storage of feline germ cells. „This is a large step towards preserving biodiversity. In particular to endangered cat species the successful cryopreservation of female and male gametes is a ray of hope,” commented the head of the department, Prof Dr Katarina Jewgenow (IZW).

In 2007 the IZW initiated the “Felid Gametes Rescue Project” in order to build up an European network for the extraction and storage of feline gametes, which are made available to breeding programmes of zoos. Within the framework of this project, different European zoos are sending ovaries and testes of big and small cats to the IZW in Berlin for research. The scientists involved are confident that these good results will encourage even more zoos to participate in the network.

Science Daily
March 19, 2013

Original web page at Science Daily

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Amblyopia cat: Turn off the lights

A new study in cats reveals that even brief periods in total darkness can correct the vision disorder amblyopia. A stint in the dark may be just what the doctor ordered—at least if you have “lazy eye.” Researchers report that kittens with the disorder, a visual impairment medically known as amblyopia that leads to poor sight or blindness in one eye, can completely recover their vision by simply spending 10 days in total darkness. “It’s a remarkable study, with real potential to change how we think about recovery from amblyopia,” says neuroscientist Frank Sengpiel of Cardiff University in the United Kingdom who was not involved in the work. Amblyopia affects about 4% of the human population. It’s thought to start with an imbalance in vision early in life: If one eye doesn’t see as well as the other—because, for example, of a cataract or astigmatism—the brain reroutes most of the connections needed for visual processing to the “good” eye. Doctors often treat the condition by patching the good eye and forcing the brain to rely on the other eye, but the treatment risks damaging vision in the good eye, and if it doesn’t succeed or occur early enough in a child’s visual development, the vision loss in the impaired eye can be permanent.

Earlier studies with cats, whose complex visual systems are good stand-ins for human vision, showed that neurons in the brain’s visual centers shrink when the brain decides to disconnect from the bad eye, but that they grow again when the cats are placed in darkness. So neuroscientists Kevin Duffy and Donald Mitchell of Dalhousie University in Halifax, Canada, set out to test darkness itself as a treatment. They first induced amblyopia in 27 kittens by surgically closing one of each animal’s eyes 30 days after birth, when a feline’s visual system plasticity, its ability to change and grow, is at its peak. The eye was kept closed for 7 days, after which each kitten had amblyopia. Then the kittens were divided into two groups: one group that was placed in darkness immediately upon opening the deprived eye, and a second group that waited 3 months before its stint in the darkness. The darkness that both groups experienced was total—”a darkroom inside a darkroom inside a darkroom” that kept out even faint or transient sources of light, Duffy says. When the first group emerged from its 10 days of lights-out, all the kittens were blind in both eyes. But over a 7-week period, each cat’s eyes improved in lockstep, ultimately achieving normal vision in both eyes.

The second group, which during the delay had developed stable and presumably permanent amblyopia, also spent 10 days in the pitch dark. When those kittens emerged, their good eyes could still see and their bad eyes were nearly blind. But within 7 days, each kitten’s bad eye had recovered to the point that it matched the good eye in visual acuity. “This vision impairment that would have lasted a lifetime was completely obliterated by 10 days of darkness,” Duffy says. The results, published today in Current Biology, suggest that darkness restored some of the kittens’ brain plasticity and thus enabled their vision’s recovery. To understand the mechanism behind this, the researchers measured how darkness affects levels of a protein, called NF-L, that helps stabilize the shape and structure of neurons in the brain. These so-called neurofilaments accumulate with age and are thought to be molecular “brakes” that reduce the brain’s plasticity over time. They put a different group of 30-day-old kittens—a group in which the researchers did not induce amblyopia, to make sure they weren’t measuring the effects of the deprivation on neurofilament levels—into the darkness. After 10 days in the dark, these kittens showed 50% lower NF-L levels in their brain tissue than kittens of the same age that had never been kept in the dark. “It was like you were looking at an animal that was much younger than it was,” Duffy says. Sengpiel cautions that it’s too soon to start suggesting doses of dark for humans with amblyopia, in part because the researchers haven’t yet determined the limits of their treatment’s effectiveness. They don’t know, for example, just how dark the room has to be, or whether short breaks from the darkness would destroy its benefits. Duffy and Mitchell hope to answer some of those questions in future studies.

ScienceNow
March 5, 2013

Original web page at ScienceNow

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How the tabby got its blotches

Domestic cats often resemble their larger, wilder counterparts—with black, striped, or tawny fur that presumably helps the big hunters blend into the landscape. For scientists, the genes involved in the evolution of cats’ color patterns have been equally well-camouflaged. But a new study appearing online today in Science reveals a mutation shared by housecats and cheetahs, which may explain how the cat got its stripes—or in this case, its blotches. The sharp, evenly spaced stripes of the tabby cat are among the most common of coat patterns. In some tabbies, however, the stripes look more like long, irregular swirls. Although fairly common in domestic cats, this pattern (called “blotched” by geneticists and cat fanciers) is unusual in the wild. In fact, cheetahs with the blotched pattern were initially thought to be a separate species—they were crowned with the name king cheetahs to distinguish them from the more common, spotted kind. To pinpoint the gene responsible for the difference, an international team of researchers scanned the genomes of feral cats that had either stripes or blotches. Their search led to an unnamed gene about which little is known except that it produces an enzyme that cuts up nearby proteins. The researchers found that every blotched tabby had mutations in both copies of this gene, whereas every striped cat had at least one copy without the mutation. They then found the distinctive mutations in the same gene among DNA samples from a pedigreed family of king cheetahs, confirming their suspicions that mutations in the gene, which they dubbed Taqpep, turned ordinary stripes into the more regal blotches.

Further scrutiny of the cheetah skin made it clear that Taqpep didn’t control the actual colors, because levels of the gene didn’t change between dark and light areas. However, another gene, Edn3, was active at the base of the black hairs. Wondering if the two genes worked in tandem to produce stripes, the researchers studied housecat embryos at several stages of development. They found that the tabby pattern appears only after the hairs begin to grow at 7 weeks of gestation. Meanwhile, levels of Taqpep increase throughout gestation. The researchers propose that very early in development, Taqpep establishes a pattern of stripes or spots, which is then implemented by varying levels of Edn3 as the embryo grows. The role of Taqpep in setting the pattern early on also explains why the number of stripes or spots doesn’t change as the cat ages (unlike in nonmammalian spotted animals such as salamanders and some fish).

“We knew the gene was out there, but we didn’t know what it did. It’s exciting to use the power of genetics to unravel these pathways,” says co-author of the study Stephen O’Brien, a geneticist who was then at the National Laboratory for Cancer Research in Frederick, Maryland, but now heads the Theodosius Dobzhansky Center for Genome Informatics in St. Petersburg, Russia. The possibility that Taqpep might be involved in pigment was totally off anyone’s radar,” says geneticist Sheila Schmutz of the University of Saskatchewan in Saskatoon, Canada. “Scientists who study color patterns now have a totally new gene with a well-defined function to work with.” O’Brien and his collaborators Gregory Barsh and Christopher Kaelin of the HudsonAlpha Institute for Biotechnology in Huntsville, Alabama, wonder why cats have frequently spawned this plethora of color variation and why the blotch-producing Taqpep mutation didn’t simply disappear after one or two generations in the wild. O’Brien is not convinced that protective coloration is the only survival advantage conferred by pigment-related genes like Taqpep. “Big predatory cats hunt their prey; camouflage may be helpful but isn’t essential to survival,” he notes. O’Brien predicts that color-producing genes will prove to play some other vital role—perhaps in resistance to disease. Taqpep, he says, belongs to a family of genes that are involved in immunity and produce receptors that are often co-opted by viruses seeking entry into a cell. A mutation in this gene may have helped some cats survive infection, he says. Geneticist Elaine Ostrander of the National Human Genome Research Institute in Bethesda, Maryland, says that although many papers report a gene or two linked to a particular color, this work ties together several steps in a pattern-producing pathway. “It’s an exciting missing piece of the puzzle,” she says.

ScienceNow
October 30, 2012

Original web page at ScienceNow

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First ever videos of snow leopard mother and cubs in dens recorded in Mongolia

For the first time, the den sites of two female snow leopards and their cubs have been located in Mongolia’s Tost Mountains, with the first known videos taken of a mother and cubs, located and recorded by scientists from Panthera, a wild cat conservation organization, and the Snow Leopard Trust (SLT). Because of the snow leopard’s secretive and elusive nature, coupled with the extreme and treacherous landscape which they inhabit, dens have been extremely difficult to locate. This is a tremendous discovery and provides invaluable insight into the life story of the snow leopard. Dr. Tom McCarthy, Executive Director of Panthera’s Snow Leopard Program stated, “We have spent years trying to determine when and where snow leopards give birth, the size of their litters, and the chances a cub has of surviving into adulthood. This is one of those exceptional moments in conservation where after years of effort, we get a rare glimpse into the life of an animal that needs our help in surviving in today’s world. These data will help ensure a future for these incredible animals.” A short video of the female and her cub who were bedded down in a partially human-made den was recorded from a safe distance by Örjan Johansson, Panthera’s Snow Leopard Field Scientist and Ph.D. student, using a camera fixed to an extended pole.

The team, which included a veterinarian, entered the two dens (the first with two cubs, and the second containing one cub) while the mothers were away hunting. All three cubs were carefully weighed, measured, photographed and other details were recorded. Two of the cubs were fixed with tiny microchip ID tags (the size of a grain of rice) which were placed under their skin for future identification. The utmost care was taken in handling the animals to ensure they were not endangered, which was the top priority of the team at all times. In the following days, the team monitored the mothers’ locations to ensure that they returned to their dens and their cubs, which they successfully did. “Knowledge about the first days and weeks of life is vital to our understanding of how big cat populations work, and how likely it is for a newborn to reach adulthood and contribute to a healthy population. A valid conservation program requires such information, which this new development in snow leopard research provides,” said Dr. Howard Quigley, Panthera’s Executive Director of both Jaguar and Cougar Programs.

Referred to by locals as ‘Asia’s Mountain Ghost,’ knowledge of snow leopards in general is quite limited due to the cat’s elusive nature, and even less is known about rearing cubs and cub survival in the wild. Until now, what is known has mostly been learned from studying snow leopards in zoos. Although snow leopard litters typically consist of one to three cubs in a captive zoo environment, no information exists regarding litter size in the wild. As wild snow leopard cubs are subject to natural predators, disease, and also human threats such as poaching or capture for the illegal wildlife market, the percentage of cubs which survive to adulthood has until now only been speculated. The use of PIT tags and observations of snow leopard rearing in the wild will allow our scientists to learn about the characteristics of a typical natal den and speculate how a den is selected, how long snow leopard cubs remain in dens, when cubs begin to follow their mothers outside of the dens, how often and how long the mother leaves the cubs alone to hunt, how many cubs are typically born in the wild, and other valuable data.

Science Daily
July 24, 2012

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Skulls shed new light on the evolution of the cat

Modern cats diverged in skull shape from their sabre-toothed ancestors early in their evolutionary history and then followed separate evolutionary trajectories, according to new research from the University of Bristol published today in PLoS ONE. The study also found that the separation between modern domestic cats and big cats such as lions and tigers is also deeply rooted. Dr Manabu Sakamoto and Dr Marcello Ruta in the School of Earth Sciences studied the skull shape of extinct sabre-toothed cats, modern (conical-toothed) cats and prehistoric ‘basal’ cats (ancestors of modern cats). This is the first time these three different types of cats have been analysed together in a single dataset. The researchers quantified skull shape by taking various measurements, adjusting these measurements for size differences, then investigating the distribution of cat skulls in shape-space. By estimating ancestral positions through shape-space and time, they investigated patterns of skull shape evolution across the cat family tree.

They found an early and conspicuous divergence between the conical-toothed cats and sabre-toothed cats, with all sabre-toothed cats being more closely related to each other than they were to modern conical-toothed cats. There was also a marked separation between modern small-medium cats (that is, the domestic cat and its close relatives, the cheetah, puma, ocelot, serval and lynx) and modern big cats (such as the lion, tiger, leopard and jaguar), with a divergence in skull shape early in their evolutionary history. This means that small-medium cats and large cats followed different evolutionary trajectories with respect to skull shape. Dr Sakamoto said: “Our study is the first to determine the interrelationships between modern conical-toothed cats, sabre-toothed cats, and some basal cats. “It also highlights how simple measurements can be used not only to investigate shape-space distribution, but also to successfully discriminate and identify different cat species – this could be useful for museums who may have as yet unidentified cat specimens in their collections. “Lastly, our results show that differences in cat skull shape have deeply rooted evolutionary histories, first between the sabre-toothed and conical-toothed cats, and then between small-medium and large cats.”

PhysOrg.com
July 24, 2012

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Highly divergent novel lyssavirus in an African civet

Evidence in support of a novel lyssavirus was obtained from brain samples of an African civet in Tanzania. Results of phylogenetic analysis of nucleoprotein gene sequences from representative Lyssavirus species and this novel lyssavirus provided strong empirical evidence that this is a new lyssavirus species, designated Ikoma lyssavirus. Eleven Lyssavirus species have been classified: Rabies virus (RABV), Lagos bat virus (LBV), Mokola virus (MOKV), Duvenhage virus (DUVV), European bat lyssavirus types -1 and -2, Australian bat lyssavirus, Aravan virus, Khujand virus, Irkut virus, and West Caucasian bat virus (WCBV). All these viruses except MOKV have been detected in bats. Two newly identified lyssaviruses, Shimoni bat virus (SHIBV) and Bokeloh bat lyssavirus, both detected in bats, have not yet been classified. The presence of numerous lyssaviruses in bat species has led to increasing research efforts toward lyssavirus discovery in bat populations globally. However, lyssavirus surveillance in terrestrial mammals remains limited across most of Africa.

Of the 13 lyssaviruses, 5 circulate in Africa (RABV, LBV, MOKV, DUVV, and SHIBV). LBV, MOKV, DUVV, and SHIBV are detected exclusively in Africa, whereas RABV is detected worldwide. The predominant RABV variants circulating in Africa are the mongoose and canine biotypes. In South Africa, canine RABV is considered to have been introduced in the eastern Cape Province after importation of an infected dog from England in 1892 and subsequently spread, infecting domestic and wild carnivores. Separate introductions of canine RABV (particularly in northern Africa) have been suggested. In addition, molecular clock analysis indicates that mongoose RABV was present in southern Africa ≈200 years before the introduction of canine RABV. In Tanzania, canine RABV is endemic and widespread throughout the country. In the Serengeti ecosystem, detailed studies have shown a single variant of canine RABV circulating in multiple host species. However, annual mass rabies vaccination campaigns have been conducted for dogs in villages surrounding Serengeti National Park since 2003, and rabies has not been detected in the park since 2000. Enhanced laboratory-based surveillance in support of this canine rabies elimination program has been running concurrently in the region.
Read more: http://wwwnc.cdc.gov/eid/article/18/4/11-1553_article.htm

Emerging Infectious Diseases
May 1, 2012

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Risk factors for cat cancer could have human implications

A recent, large-scale study on cat intestinal cancer has provided new insight into a common pet disease and its causes; the findings could ultimately benefit humans. We are looking for patterns of cancer development in animals, so we can find common risk factors,” said Kim Selting, associate teaching professor of oncology at the MU College of Veterinary Medicine. “I mentored a former resident, Kerry Rissetto, as she examined intestinal tumors in cats on a very large scale, and we believe we can use this information to eventually identify cancer risk factors and treatments for humans.” Using a database, the researchers examined 1,129 cases covering 47 years of intestinal cancer in cats. The researchers found that most feline intestinal cancers were lymphoma, or cancer of the immune system, and most cancers were found in the small intestines. The researchers also determined that the Siamese breed, particularly males seven years old or older, had an increased risk of developing intestinal cancer.

“This is important because there are very few population-based studies that allow us to evaluate cancer and risk factors on such a large scale,” Selting said. “Pet owners should be on the lookout for unexplained weight loss, vomiting and diarrhea, because these issues can be associated with intestinal cancer.” Selting says that tracking animal cancer is important because animals share the environment with humans. By noting patterns of cancer development, doctors and veterinarians may become aware of environmental factors that could be causing tumor progression in different species, including humans. “Animal health care may predict what could be coming for human health care,” Selting said. “For example, dogs are really the only species, other than humans, that develop the toughest type of prostate cancers. If a treatment develops that can help with prostate cancer, we can test it on dogs and find results faster because cancer in dogs progresses faster than cancer in humans.”

Science Daily
October 18, 2011

Original web page at Science Daily

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Glowing kittens fight feline AIDS

Scientists have genetically modified cats by infecting their eggs with a virus containing a foreign gene—the first time this method has worked in a carnivore. Experts say the advance could make the cat a valuable new genetic model—and potentially protect it from an HIV-like virus. There are two AIDS epidemics in the world: one in humans, the other in cats. Whereas we can become infected with the human immunodeficiency virus (HIV), cats fall victim to the feline immunodeficiency virus (FIV), which causes nearly identical symptoms. The viruses, known as lentiviruses, are different enough that cats can’t catch HIV and people can’t get FIV, but most of their basic biochemistry is the same. Previous studies have suggested that a protein called TRIMCyp is what keeps humans and monkeys from being infected with FIV. The protein, which cats lack, is thought to recognize the virus’s outer shell and target it to be degraded.

Eric Poeschla, a molecular virologist at the Mayo Clinic in Rochester, Minnesota, wanted to figure out if giving cats the TRIMCyp gene would make them immune to FIV. But the only proven way of getting a new gene into a cat, somatic cell nuclear transfer, is tricky. The technique, which produced the famous sheep Dolly, involves replacing the nucleus of an egg cell with a nucleus from an adult cell that contains new genes, then implanting the egg into a female. The strategy works in only a fraction of cases. In cats it’s been used to create glowing kittens with no other traits, just proof that it can be made to work. Poeschla and his colleagues turned to a different method—using a virus to carry genes into an egg cell—that had worked in animals including mice and cows but never been successful in a carnivore. Because cells are readily infected by lentiviruses, the researchers made a lentivirus containing the TRIMCyp gene as well as a gene that encodes for a fluorescent protein. The latter allowed them to easily visualize which cells contained the new genetic material—cats with the gene glow green. After allowing the virus to infect the eggs, the team fertilized them with normal cat sperm and injected them into the fallopian tubes of 22 female cats. Each cat received 30 to 50 eggs.

Five cats became pregnant, with 11 embryos between them, the team reports online in Nature Methods. Ten of the embryos contained the new genes, and five gave rise to kittens, three of which are still alive. (One kitten was stillborn and another died during birth.) The 23% success rate is much higher than the typical 3% seen with somatic cell nuclear transfer, Poeschla says. As well as a high number of animals per pregnancy, the number of transgenic animals per embryo is also high. “A big advantage is efficiency. Almost all of the offspring are transgenic [carry the new gene], so you’re not screening hundreds of animals to find the transgenic ones.” The method’s efficiency is only half the story, however. When the researchers tried to infect blood cells from the genetically modified kittens with FIV, the virus didn’t replicate well. Poeschla and colleagues next plan to test whether the cats are resistant to FIV, or, if not, whether they are less likely to develop feline AIDS after infection. Researchers can use the same method to test whether other antiviral proteins from humans and monkeys affect the transmission of FIV, says veterinarian Susan VandeWoude of Colorado State University in Fort Collins. The advance also makes it easier to use cats as model organisms for other biological questions, she says. For example, the visual cortex of a cat’s brain is a better model for humans than the visual cortex from mice is. With an easier way to modify genes related to vision, researchers may be able to gain an even higher understanding of how this part of the brain works. “I think cats will become easier to utilize as a model organism now that you can manipulate the genome,” VandeWoude says. “They’re not going to replace mice, but it gives another tool to scientists.”

ScienceNow
September 20, 2011

Original web page at ScienceNow

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The low genetic diversity of the Iberian lynx may not decrease the species’ chance of survival

Research looking at DNA from Iberian lynx fossils shows that they have had very little genetic variation over the last 50,000 years, suggesting that a small long-term population size is the ‘norm’ in the species and has not hampered their survival. The new study is published in the journal Molecular Ecology. Conservationists previously thought that having low genetic diversity would doom a species to extinction, through inbreeding and reduced ability to adapt to changing environments. Such a lack of genetic diversity, also seen in other cat species such as African cheetahs, lions of the Ngorongoro crater and the Florida panther, is usually thought to be the result of population bottlenecks. The effect of human activity or the dramatic ecosystem changes at the end of the last ice age caused by the Holocene warming around 10,000 years ago are common explanations for the phenomenon. However, when researchers in Spain, Denmark and Sweden extracted DNA from the fossil bones and teeth of Iberian lynx, covering a period of at least the last 50,000 years, they found no genetic variation over that period. They were looking at mitochondrial DNA – a part of the genome that is usually very variable.

“At first this result was very surprising,” said Ricardo Rodríguez from the Instituto de Salud Carlos III in Madrid, a lead author of the study. “It is not unusual to see low genetic diversity in living members of a species, but when people have looked at fossil DNA – especially from fossils older than 10,000 years – much more diversity is usually seen.” In collaboration with researchers at UCL (University College London), they were able to show that such patterns are best explained by relatively small long-term population sizes over that period. “To see so little genetic diversity over such a long period of time indicates that populations sizes were moderate” said Professor Mark Thomas from the Department of Genetics, Evolution and Environment at UCL, a co-author on the study. “But if small populations can exist for so long and with so little genetic diversity then this must say something about the survivability of similar endangered species today.” The Iberian lynx is currently considered the most threatened cat species in the world and is the most endangered carnivore in Europe. The International Union for Conservation of Nature has classified it as critically endangered. Despite being distributed throughout the Iberian peninsula in the past, lynx are now only found in two small isolated populations in southern Spain which together harbour no more than 279 individuals. This recent reduction in population size has been caused by habitat destruction, the decline of its main prey species – the European rabbit – and excessive hunting, even in the recent past.

“Most importantly, these results show that low genetic diversity in the Iberian lynx is not in itself an indication of a population in crisis” said Dr. Love Dalén from the Swedish Museum of Natural History, senior author on the study. “What’s more, our results may help conservation biologists to assess how large a population needs to be to ensure its long-term survival, something which is a topic of an ongoing debate in many countries, especially for large carnivores.” “One clear message of our study is that a lack of genetic diversity in an endangered species should not hamper conservation efforts” added Dr. Cristina Valdiosera from Copenhagen University. “It’s a myth that certain species are doomed by their genetics. If a species is doomed, it is only doomed by a lack of will to conserve it”. More information: ‘50,000 years of genetic uniformity in the critically endangered Iberian lynx’ is published online in the journal Molecular Biology today.

PhysOrg.com
September 6, 2011

Original web page at PhysOrg.com

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Bolstering genetic diversity among cheetahs

Researchers at the Smithsonian Conservation Biology Institute have discovered why older females are rarely able to reproduce — and hope to use this information to introduce vital new genes into the pool. SCBI scientists and collaborating researchers analyzed hormones, eggs and the uteri of 34 cheetahs at eight institutions, and determined that while the hormones and eggs of cheetahs older than 8 years appear normal, the animals’ uterine tracks tend to suffer from abnormal cell growth, infections and cysts that prevent pregnancy. “Those of us who work with cheetahs have anecdotally noted that it’s hard to reproduce older cheetahs, but this is the first time anyone has documented how aging affects the physiology of reproduction in this species,” said Adrienne Crosier, SCBI cheetah biologist and lead author of the study in which these results were published. “We were relieved to find that, unlike in other older mammals, the eggs in older cheetahs can produce viable-appearing and growing embryos, which means we may be able to transfer them to younger cheetahs and preserve genetic diversity. If we had found that the eggs were abnormal, we were facing losing genes in an already depleted population.”

The researchers’ findings were published in a paper titled “Increasing age influences uterine integrity, but not ovarian function or oocyte quality, in the cheetah (Acinonyx jubatus)” in the online version of the Biology of Reproduction in May and in final form this month. According to the study, approximately 80 percent of adult female cheetahs in North American institutions have never reproduced and the death rate for cheetahs has exceeded the birth rate in 13 of the last 16 years. Lack of genetics can lead to cub mortality and lower cheetahs’ resistance to disease. The next step for SCBI researchers is to extract eggs from a cheetah older than 8 years that has not reproduced and to fertilize the eggs and transfer them to a younger female. Crosier estimates that SCBI will try an embryo transfer within the next two years and said that if it works, it is feasible that someday researchers could do this with wild cheetahs to continue to infuse the population in human care with new genes.

Paper co-author, Pierre Comizzoli, a vertebrate cryobiologist at SCBI, has been collecting and freezing immature eggs and ovarian tissues from felids for the SCBI’s Genome Resource Bank, a frozen repository of biological materials that includes sperm and embryos, tissues, blood products and DNA. Researchers are currently able to produce embryos from fresh eggs, but aim to do the same with frozen eggs. “The work on freezing eggs and ovarian tissues will offer yet another option to preserve the fertility of females, especially long after they are dead,” Comizzoli said. “These approaches also allow us to to boost the number of offspring that can be produced from a single individual.” SCBI is one of five centers participating in research to boost the cheetah population in human care as part of the Conservation Centers for Species Survival, also known as C2S2. All five centers collectively manage more than 25,000 acres of land devoted to the survival of threatened species with special needs (including those requiring large land areas, natural group sizes and minimal public disturbance). All five centers maintain a cheetah breeding facility as part of their long-term commitment to cheetah breeding and research. The Smithsonian’s National Zoo’s Front Royal facility currently houses 10 adult cheetahs and seven cubs. The National Zoo houses three adults. Cheetahs, the fastest animals on land, are struggling to outpace threats to their survival in the wild. As the result of human conflict, hunting and habitat loss, there are only an estimated 7,500 to 10,000 cheetahs left in the wild. The International Union for Conservation of Nature considers cheetahs a vulnerable species.

Science Daily
August 23, 2011

Original web page at Science Daily

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Few replicas as first cloned cat nears 10

She may be slowing down a bit these days, and her grey and white figure has gotten a bit plump after giving birth to kittens three years ago, but that’s part of what makes CC so extraordinary: she is completely normal. “People expect there to be something different about her,” said Duane Kraemer, a Texas A&M University researcher who was part of the team that cloned her. “We took her to a cat show once. A guy who came by to see her said she looks like any other barn cat.” CC — which stands for Carbon Copy — was born in an A&M lab on December 22, 2001, from a cell taken from a calico cat named Rainbow that was inserted into another cat’s embryo. The embryo was then implanted into a surrogate named Allie. While CC has Rainbow’s exact genetic construct, she lacks her orange coloring because generally only two colors — not three — can be transferred when cloning calicos. “Cloning is reproduction, not resurrection,” Kraemer told AFP in an interview at his College Station home.

That — along with a price tag which could reach six figures — is one of the main reasons why cloning pets hasn’t worked out. Too few pet owners sought its services, Lou Hawthorne, the head of BioArts, wrote on the company’s web site two years ago when explaining why the firm was getting out of the pet cloning business. “After studying this market for more than a decade — and offering both cat and dog cloning services — we now believe the market is actually extremely small,” he wrote on BioArts’ now-defunct website. And while many of its dog clones turned out normal, researchers could not explain why some were plagued by physical defects. “One clone — which was supposed to be black and white — was born greenish-yellow where it should have been white,” he wrote. “Others have had skeletal malformations, generally not crippling though sometimes serious and always worrisome,” he added. “These problems are all the more worrisome given that cloning is supposedly a mature technology in general.”

PhysOrg.com
August 23, 2011

Original web page at PhysOrg.com

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Even healthy cats act sick when their routine is disrupted

A cat regularly vomiting hairballs or refusing to eat probably isn’t being finicky or otherwise “cat-like,” despite what conventional wisdom might say. There is a good chance that the cat is acting sick because of the stress caused by changes in its environment, new research suggests. Healthy cats were just as likely as chronically ill cats to refuse food, vomit frequently and leave waste outside their litter box in response to changes in their routine, according to the Ohio State University study. Veterinary clinicians refer to these acts as sickness behaviors. The researchers documented sickness behaviors in healthy cats and in cats with feline interstitial cystitis, a chronic illness characterized by recurring discomfort or pain in the bladder and often both an urgent and frequent need to urinate.

When the cats experienced what were called “unusual external events,” such as a change in feeding schedule or caretaker, the healthy cats were just as likely to exhibit sickness behaviors as were the chronically ill cats. The two groups had the same number of sickness behaviors in response to unusual events, and both groups were at more than three times the risk of acting sick when their routines were disrupted. Previous research has indicated that a diagnosis of interstitial cystitis, known as IC, in cats is strongly associated with a number of other health problems. The fact that healthy cats exhibit some of those same problems in the face of stress suggests that veterinary clinicians should consider cats’ environmental conditions during assessments for health problems, researchers say.

“For veterinary clinicians, when you have a cat that’s not eating, is not using the litter box or has stuff coming up out of its mouth, the quality of the environment is another cause that needs to be addressed in coming up with a diagnosis,” said Tony Buffington, professor of veterinary clinical sciences at Ohio State and senior author of the study. “We are cautious about extrapolating these findings to the average home, but we will say that anyone who has a pet accepts the responsibility of understanding their pet’s needs and providing them,” he added. “And what we’ve learned is that all cats need to have some consideration of environmental enrichment.” The study is published in the Jan. 1, 2011, issue of the Journal of the American Veterinary Medical Association.

This research project didn’t begin as a study of cats’ tendency to exhibit sickness behaviors. Ohio State’s Veterinary Medical Center was housing 12 healthy cats and 20 cats with IC, including those at risk of euthanasia because their previous owners were unable to tolerate their sickness behaviors, for a variety of other research efforts, many related to better understanding the chronic disease. Judi Stella, a doctoral candidate in veterinary preventive medicine, was the primary caretaker of this colony of cats. Based on previous work by Buffington about the benefits of environmental enrichment for cats that stay indoors, Stella spent months setting up a standardized feeding, play and cleaning schedule that seemed the least stressful for all of the cats. And then she noticed that the cats with the chronic illness looked better: Their coats were shinier, their eyes were clearer and, perhaps most surprising of all, none of these cats missed the litter box or vomited for two weeks. “At the time, we assumed the IC cats were always going to have these problems. When I started looking at the data, it was the lack of sickness behaviors that tipped me off. It was not expected,” said Stella, lead author of the study.

“This became a study of enrichment as an approach to therapy for these syndromes because there is no good drug therapy in cats, or in people, for that matter, with this disorder. What we found, in other clinical studies and with this study, is that by enriching the environment, you can reduce IC cats’ symptom burden by about 75 or 80 percent,” Buffington said. Another important finding: “A healthy cat — or any healthy mammal — can feel the stress of environmental disruption and exhibit sickness behaviors as a result,” he said. After the environment was stable for all of the cats, Stella observed them for another 77 weeks. The nature of the research changed again over the course of the observation. When Stella took a vacation and was replaced by substitute caretakers, or when she changed the feeding schedule for the cats as part of yet another project, it became clear that these changes had an influence on the cats’ sickness behaviors. So she tracked those changes. During the period of observation, these changes — called unusual external events — included a discontinuation of contact with Stella, the longtime primary caretaker; a combination of husbandry schedule changes, food removal, restraint stress and withdrawal of playtime and music; a three-hour delay in feeding time; and a dramatic change in caretaker personnel.

During control weeks, when the routine was unaltered, the healthy cats, on average, exhibited 0.4 sickness behaviors and the cats with IC exhibited 0.7 sickness behaviors — virtually no difference. Similarly, during weeks containing unusual external events, those numbers increased to 1.9 sickness behaviors for healthy cats and 2.0 sickness behaviors for cats with interstitial cystitis. Overall, this translated to a 3.2-fold increase in the risk for sickness behaviors by all cats when their routines were disrupted. The three most common sickness behaviors — vomiting, urination or defecation outside the litter box and decreased food intake — accounted for 88 percent of all sickness behaviors in healthy cats and 78 percent of sickness behaviors in the cats with IC. Buffington noted that these three signs of illness are among those that often lead pet owners to take their cats to a veterinarian for evaluation. And interestingly, these sickness behaviors also are seen in other captive housing environments, such as zoos, kennels and shelters.

So how does a cat owner enrich the animal’s environment? In this study, this included routine care and feeding at the same time every morning, keeping food and litter boxes in consistent locations, daily cleaning of cages, provision of a clean litter box, regularly washed bedding, hiding boxes, numerous commercial cat toys and classical music for one to two hours each day. Stella also released all cats from their cages for 60 to 90 minutes each afternoon to allow them to interact and play with toys or use climbing and scratching posts. “I think a huge part of this is giving cats resources they can interact with and control. Litter boxes and food bowls go without saying, but I also think that equally important are predictable schedules and some semblance of control so they don’t feel trapped. And their humans can focus on quality interaction rather than the quantity of interaction. Understanding how they live in the world can allow humans to interact with them more effectively,” Stella said. There is also a need to recognize that what might be common isn’t necessarily normal. “There is not another mammal on the planet that wouldn’t be hospitalized for throwing up once a week,” Buffington said. “Vomiting hairballs is not normal. What we think happens is that stress changes motility in their stomach and that leads to vomiting. Pet owners have to recognize that vomiting is not normal in cats.”

The researchers noted a few other findings of interest: Older cats had a higher risk for an increase in the total number of sickness behaviors and for an increase in upper gastrointestinal symptoms and avoidance behavior. The oldest cat in the study was 8 years old. In addition, the sickness behaviors of cats with interstitial cystitis were reduced even though they were not treated with any drugs and were eating commercially available dry food, which suggests these cats do not require drugs or special diets as part of their therapy. “You get the environment right and they’ll recover,” Buffington said. “It’s like having lactose intolerance — you can’t put the corrective gene into the intestinal tract, but you can teach people to avoid milk sugar and that’s just as good. That’s what we’re doing — teaching these cats how to avoid threats that cause stress.”

Science Daily
January 11, 2011

Original web page at Science Daily

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Protein helps parasite survive in host cells

Toxoplasma gondii and other related parasites surround themselves with a membrane to protect against factors in host cells that would otherwise kill them. Scientists at Washington University School of Medicine in St. Louis have identified a parasite protein that protects this membrane from host proteins that can rupture it. According to the researchers, disabling the parasite’s defensive protein could help give hosts an advantage in the battle against infection. In a study published in Cell Host & Microbe, scientists show that the ROP18 protein disables host cell proteins that would otherwise pop a protective bubble the parasite makes for itself. The parasite puts the bubble on like a spacesuit by forming a membrane around itself when it enters host cells. This protects it from the hostile environment inside the cell, which would otherwise kill it. “If we can find therapies that block ROP18 and other parasite proteins like it, that could give the host the upper hand in the battle against infection,” says first author Sarah Fentress, a graduate student in the laboratory of L. David Sibley, PhD, professor of molecular microbiology.

Infection with Toxoplasma, or toxoplasmosis, is most familiar to the general public from the recommendation that pregnant women avoid changing cat litter. Cats are commonly infected with the parasite, as are some livestock and wildlife. “The exact role of ROP18 and related proteins in human disease remains to be studied,” says Sibley. “But mice are natural hosts of Toxoplasma, so studies in laboratory mice are relevant to the spread of infection.” Epidemiologists estimate that as many as one in every four humans is infected with Toxoplasma. Infections typically cause serious disease only in patients with weakened immune systems. In some rare cases, though, infection in patients with healthy immune systems leads to serious eye or central nervous system disease, or congenital defects or death in the fetuses of pregnant women.

In the new study, Fentress showed that the ROP18 protein binds to a class of host proteins known as immunity-related GTPases. Tests in cell cultures and animal models showed that this binding leads to a reaction that disables the GTPases, which normally would rupture the parasite’s protective membrane. “With one exception, humans don’t have the same family of immunity-related GTPases,” Fentress notes. “But we do have a similar group of immune recognition proteins called guanylate-binding proteins, and we are currently testing to see if ROP18 deactivates these proteins in human cells in a similar manner.” The findings could be applicable to other parasites and pathogens. Toxoplasmosis belongs to a family of parasites that includes the parasite Plasmodium, which causes malaria. All surround themselves with protective membranes when they enter host cells. “Plasmodium doesn’t make ROP18, but it does secrete related proteins called FIKK,” says Fentress. “It’s possible they also act to thwart host defense mechanisms like GTPases and guanylate-binding proteins.”

PhysOrg.com
January 11, 2011

Original web page at PhysOrg.com