Tag Archives: Reproduction

Chlorhexidine umbilical cord care can save newborn lives

Cleansing a newborn’s umbilical cord with chlorhexidine can reduce an infant’s risk of infection and death during the first weeks of life by as much as 20 percent, according to a study led by researchers at the Johns Hopkins Bloomberg School of Public Health. The study, conducted in rural Bangladesh in partnership with ICDDR,B and […]

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Gene mutation discovery sparks hope for effective endometriosis screening

Researchers at Yale School of Medicine have, for the first time, described the genetic basis of endometriosis, a condition affecting millions of women that is marked by chronic pelvic pain and infertility. The researchers’ discovery of a new gene mutation provides hope for new screening methods. Published in the Feb. 3 early online issue of […]

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Saving the snow leopard with stem cells

The survival of the endangered snow leopard is looking promising thanks to Monash University scientists who have, for the first time, produced embryonic stem-like cells from the tissue of an adult leopard. Never before have induced pluripotent stem (iPS) cells, which share many of the useful properties of embryonic stem cells, been generated from a […]

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Not tonight deer: A new birth control vaccine helps reduce urban deer damage

A new birth control vaccine for white-tailed deer — a growing nuisance in urban areas for gardens and landscaping — eliminates the dangerous reproductive behavior behind the annual autumn surge in automobile-deer collisions. The vaccine, just becoming commercially available in some U.S. states, was the topic of a report in Denver at the 242nd National […]

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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 […]

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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 […]

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New insights into biology of germ cells: Machinery for recombination is part of chromosome structure

During the development of gametes, such as egg and sperm cells in humans, chromosomes are broken and rearranged at many positions. Using state of the art technology, the research group of Franz Klein, professor for genetics at the Max F. Perutz Laboratories of the University of Vienna, has analyzed this process at high resolution. The […]

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There’s no magic number for saving endangered species

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A new study offers hope for species such as the Siberian Tiger that might be considered ‘too rare to save’, so long as conservation efforts can target key threats. The findings have important implications for conserving some of the world’s most charismatic endangered species, which often exist in populations far smaller than the many thousands […]

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Larger female hyenas produce more offspring

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When it comes to producing more offspring, larger female hyenas outdo their smaller counterparts. A new study by Michigan State University researchers, which appears in Proceedings of the Royal Society, revealed this as well as defined a new way to measure spotted hyenas’ size. “This is the first study of its kind that provides an […]

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Oldest known wild bird in US returns to Midway to raise chick

The oldest known U.S. wild bird — a coyly conservative 60 — is a new mother. The bird, a Laysan albatross named Wisdom, was spotted a few weeks ago with a chick by John Klavitter, a U.S. Fish and Wildlife Service biologist and the deputy manager of the Midway Atoll National Wildlife Refuge. The bird […]

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Whooping cranes head back to Louisiana

Officials with the Louisiana Department of Wildlife and Fisheries (LDWF) are finalizing plans to release a small flock of whooping cranes (Grus americana) in a protected wetland, in what could be a promising step towards long-term viability for an endangered species. The move would represent the return of a long-lost native — absent from the […]

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Biological clock ticks slower for female birds who choose good mates

In birds as in people, female fertility declines with age. But some female birds can slow the ticking of their biological clocks by choosing the right mates, says a new study. Female birds become progressively less fertile as age takes its toll, said co-author Josh Auld of the National Evolutionary Synthesis Center in Durham, North […]

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Viable female and male mice from two fathers produced using stem cell technology

Using stem cell technology, reproductive scientists in Texas, led by Dr. Richard R. Behringer at the M.D. Anderson Cancer Center, have produced male and female mice from two fathers. The achievement of two-father offspring in a species of mammal could be a step toward preserving endangered species, improving livestock breeds, and advancing human assisted reproductive […]

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Identification codes inserted into mouse embryos

Researchers from the Department of Cell Biology, Physiology and Immunology at Universitat Autònoma de Barcelona (UAB), in collaboration with researchers from the Institute of Microelectronics of Barcelona (IMB-CNM) of the Spanish National Research Council (CSIC), have developed an identification system for oocytes and embryos in which each can be individually tagged using silicone barcodes. Researchers […]

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Critically endangered tree frog bred for first time

As frogs around the world continue to disappear — many killed by a rapidly spreading disease called chytridiomycosis, which attacks the skin cells of amphibians — one critically endangered species has received an encouraging boost. Although the La Loma tree frog, Hyloscirtus colymba, is notoriously difficult to care for in captivity, the Panama Amphibian Rescue […]

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Protein sets stage for exchanges of DNA code in eggs and sperm

A team led by a scientist at the University of Pittsburgh School of Medicine has discovered a regulatory protein that influences where genetic material gets swapped between maternal and paternal chromosomes during the process of creating eggs and sperm. The findings, which shed light on the roots of chromosomal errors and gene diversity, appear in […]

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Early reproduction retains fertility in cheetah females

Reproduction in free-ranging female cheetah in Namibia is far better than expected. Their reproductive organs are healthy and approximately 80 percent of their young reach adulthood. With these findings, scientists from the Leibniz Institute for Zoo and Wildlife Research (IZW) in Berlin have overturned the established dogma that cheetahs generally reproduce badly due to their […]

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‘Artificial ovary’ develops oocytes into mature human eggs

Researchers at Brown University and Women & Infants Hospital have invented the first artificial human ovary, an advance that provides a potentially powerful new means for conducting fertility research and could also yield infertility treatments for cancer patients. The team has already used the lab-grown organ to mature human eggs. “An ovary is composed of […]

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Guppies: Rapid growth in adolescence leads to fewer offspring

University of California, Riverside biologists working on guppies — small freshwater fish that have been the subject of long-term studies — report that rapid growth responses to increased food availability after a period of growth restriction early in life have repercussions in adulthood. Based on their experiments, the biologists found that female guppies that grew […]

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Rainfall-driven sex-ratio genes in African buffalo suggested by correlations between Y-chromosomal haplotype frequencies and foetal sex ratio

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The Y-chromosomal diversity in the African buffalo (Syncerus caffer) population of Kruger National Park (KNP) is characterized by rainfall-driven haplotype frequency shifts between year cohorts. Stable Y-chromosomal polymorphism is difficult to reconcile with haplotype frequency variations without assuming frequency-dependent selection or specific interactions in the population dynamics of X- and Y-chromosomal genes, since otherwise the […]

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Breakthrough findings on early embryonic development

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Scientists at the Genome Institute of Singapore (GIS) have recently generated significant single cell expression data crucial for a detailed molecular understanding of mammalian development from fertilization to embryo implantation, a process known as the preimplantation period. The knowledge gained has a direct impact on clinical applications in the areas of regenerative medicine and assisted […]

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Mouse sperm cells team up with their kin in the race to fertilize eggs

The sperm of some rodents form trains to speed their passage to the egg. The sperm of a mouse can recognize and team up with sperm from the same male, US biologists have found. The discovery is further evidence that, far from being simply shells loaded with DNA, sperm cells have evolved sophisticated social behaviours […]

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The sex wars of ducks: An evolutionary battle against unwanted fertilization

The twisted sex life of Muscovy ducks is the result of an evolutionary battle between males and females. Scientists have elucidated the mechanism by which female ducks thwart forced copulations. Unwanted sex is an unpleasant fact of life for many female ducks. After carefully selecting a mate, developing a relationship and breeding, a female must […]

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Stem cells changed into precursors for sperm, eggs

Human embryonic stem cells derived from excess IVF embryos may help scientists unlock the mysteries of infertility for other couples struggling to conceive, according to new research from the Stanford University School of Medicine. Researchers at the school have devised a way to efficiently coax the cells to become human germ cells — the precursors […]

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Minimum population size targets too low to prevent extinction?

Conservation biologists are setting their minimum population size targets too low to prevent extinction. That’s according to a new study by University of Adelaide and Macquarie University scientists which has shown that populations of endangered species are unlikely to persist in the face of global climate change and habitat loss unless they number around 5000 […]

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Wolf in coyote’s clothing

Farmers depend on hybrid vigor for improved crop yields, as seeds produced from different strains of, say, corn, can lead to superior crops. Hybrid vigor seems to have worked for coyotes in the Northeastern United States as well, according to a genetic study and physical analysis of the animals: Coyotes in this part of the […]

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Mary had a lot of lambs: Researchers identify way to accelerate sheep breeding

Mary had a little lamb, but only once a year. However, Cornell Sheep Program researchers have discovered an unusual form of a gene that prompts ewes to breed out of season as well as conceive at younger ages and more frequently. They conducted a simple genetic test to identify the presence of the unusual form […]

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Many depleted fisheries are making good progress to recovery

Fisheries scientists and conservation ecologists have put aside their differences to collaborate in a study of overexploited commercial fisheries. They say that such ecosystems can be revived and managed sustainably with existing techniques, but that these measures are being patchily applied around the world. The study marks a rare consensus between the two fields. Both […]

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121 breeding tigers estimated to be found in Nepal

The first ever overall nation-wide estimate of the tiger population brought a positive ray of hope among conservationists. The figures announced by the Nepal Government’s Department of National Parks and Wildlife Conservation (DNPWC) shows the presence of 121 (100 – 194) breeding tigers in the wild within the four protected areas of Nepal. The 2008 […]

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Animal mating choices more complex than once thought

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When female tiger salamanders choose a mate, it turns out that size does matter – tail size that is – and that’s not the only factor they weigh. Findings of a Purdue University study show that animals make more complex decisions about choosing mates than once thought. The results of Andrew DeWoody’s study, released Monday […]

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