Tag: "female" at biology news
Trio of plant genes prevent 'too many mouths'
...ing other purposes, she says. The UW team of four female
scientists serendipitously discovered what appears to be part of the pathway that tempers the production of stomata while studying a trio of genes that code for signaling receptors required for normal plant height. The scientists were working on a b...
...inct ribonuclease patterns have been identified in female
reproductive tissues. As plants with the same S-genotype cannot fertilise each other, research is focussed on identifying different S-genotypes which will help farmers to choose the best mixture of varieties to grow and will also facilitate future cr...
Meaningless sex? Male mounting reduces sexual promiscuity of females
...ies have not fully considered the possibility that female
promiscuity may be inhibited by stimuli generated by the simple act of male mounting. In the new study, a team of researchers led by Dr. Tommaso Pizzari of the University of Oxford tested this idea in the feral chicken, a sexually promiscuous species...
Study in Royal Society journal on world's only horned rodent
...ard (rspb.2005.3140) It is generally thought that female
fertility in animals is not limited by the availability of sperm. In the bitterling, a fish that lays its eggs on the gills of freshwater mussels, we showed that when females spawn with a single male fewer of their eggs were fertilised than those mat...
Sneaky sex causes fish pest
...y 14th July [session A9] where he will reveal that female
"willingness" is influenced by the temperature of ...rgan (gonopodium), fertilising the eggs inside the female
body. Male mosquito fish can reproduce over a temperature range of 14-38C, but can only produce youn...
Cigarette smoke reduces transport of hamster eggs
Eggs of female
hamsters are significantly less likely to be transported by the oviduct when the eggs or the oviduct have been exposed to cigarette smoke, and this could result in disruption of fertilization and pregnancy, according to reproductive scientists at the...
Oxytocin raises aggression, cuts anxiety during lactation; similar effects on virgin rats
...ffect direct OT insertion into the brain of virgin female
rats would have. They found that "driving up-regulation of OT receptor binding in the central amygdala, using adeno-associated viral vectors, reduced the level of anxiety and promoted social dominance behavior in virgin females." * * * A model to d...
UCI researchers define estrogen's role in limiting heart disease in women
... cardiovascular disease in women. In tests done on female
mice and mice heart cells, Dr. Ellis R. Levin and ...gen is needed for normal growth and development of female
sex organs and for functions such as bearing children. But during menopause, the body's production o...
Divergent life history shapes gene expression in brains of salmon
... Proceedings of the Royal Society B. They compared female
salmon, male salmon that will eventually undertake the well-known journey from their river birthplaces to oceans - and then migrate heroically back upstream one to three years later to spawn - and males of the same age known as "sneakers" that mature...
Endangered North Atlantic right whale study says population in crisis
...he whales in recent years continues. Data show the female
survival rate, especially for females that have just given birth, is going down at an alarming rate. Right whale calf production has increased recently, from an average of 12 calves per year prior to 2000 to between 16 and 31 calves per year from 200...
Study reveals new information on the direct and indirect mate choice in lekking animals
...t 2005 issue of The American Naturalist finds that female
great snipes are not attracted to centrally located males or previously popular sites on mating arenas (leks). The findings, which question the widespread beliefs about the lek mating system, were gathered by a team of Norwegian and Swedish biologist...
New study explores the evolution of male parental care and female multiple mating
... many females, whereas the number of offspring per female
does not increase by mating with many males. Furth...lt, various combinations of male parental care and female
multiple mating evolve. The parameters that directly favor male parental care, such as small cost of...
Extravagant but worthless gifts help a guy get the girl
... in. "In other species the deciding factors for a female
is whether she's in a sexually receptive state and...t to human courtship (model 1). Male condition and female
receptiveness are the deciding factors in non-parental care species (model 2). In both cases these w...
Bone marrow may be source of new egg-cell generation in adult mammals
...GH) researchers announced surprising findings that female
mice contrary to longstanding theories of mammali...shering in a new era in the clinical management of female
infertility and menopause," says Jonathan Tilly, PhD, director of the Vincent Center for Reproductiv...
Stem cells in bone marrow replenish mouse ovaries
...rn a long-held dogma in reproductive biology, that female
mice generate egg cells only during fetal developm...ding is "really revolutionizing how we think about female
reproductive function," Tilly says. With the help of several genetic markers that are found in germ ...
Circulating stem cells play small role in lung repair
...ccording to a team of scientists who used male and female
chromosomal differences to analyze the repair proc... transplant recipients who had received lungs from female
donors. They analyzed the origins of type II pneumocytes, a stem cell involved in the complex proce...
Behavioural ecologists elucidated how peahens choose their mates, and why
... train, the more dominant the male," they say. The female
preference for both high number of ocelli and shor...d the ocelli density and found that it did explain female
choice." In the peacock, the ocelli density of the train can only be assessed by females when males ...
New theory tests sex ratios under asymmetrical local mate competition among parasitoid wasps
.... Too many sons, or too many daughters, may mean a female
does not pass on as many copies of her genes to the next generation as another mother. The crucial determinant of sex ratio for many species will be how likely related individuals will interact, in particular whether brothers will be competing amongs...
DDT-resistant insects have additional genetic advantage that helps resistance spread
... "This suggests that by becoming DDT resistant the female
flies are passing on some unknown advantage to their progeny, presumably associated with the single metabolic enzyme (cytochrome P450) that they over express.'' "These results are important for the use of any drug, pesticide or antibiotic as they sug...
In some cases, genetic resistance takes on a life of its own
...rough the female. This suggests that DDT-resistant female
flies are passing on to their progeny some unknown advantage related to the genetic alteration that offers DDT resistance--in this case, the overexpression of a particular gene. The researchers looked at the effects of the DDT-resistance trait on fec...
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