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Tag: "males" at biology news

Found: Missing sequence of the human Y chromosome

...structural polymorphismpresent only in a subset of males in the human population, members ofRappold's laboratory ?including Stefan Kirsch, Ph.D., lead author onthe paper ?tested 100 men of different ethnic origin for the presenceof this 554-kilobase fragment. Indeed, the sequence was present in all100 indi...

The secret lives of whales

...Female sperm whales feed in tropical regions while males travel globally and feed near the poles. “For example, of the roughly one million sperm whales killed by whalers in the Antarctic Ocean, only one was a female,?says Payne. Ocean Alliance is testing its samples for 30 different pollutants. “Some of t...

Ants Genetic Engineering Leads To Species Interdependency

...ions have been discovered inwhich queens mate with males of another species to produce geneticallynovel hyb... the researchers prevented queens from mating with males of theother species, very few succeeded in making any workers at all, ahandicap that would lead to c...

Love at first smell

Why do some males smell better than others? Scientists at Cardiff Un...researchers found in a study of sticklebacks, that males with body odour that is particularly attractive to females produce small protein fragments (known as...

Sexual cooperation: Mating increases longevity in ant queens

...Drosophila). These manipulations are beneficial to males because, for example, they reduce female re-mating...ive success, living longer irrespective of whether males could transfer viable sperm or had been sterilized prior to mating. It remains unknown how mating in...

Cricket's finicky mating behavior boosts biodiversity

...pala species to the next. They refuse to mate with males of other species, thus promoting the formation of new species. The scientists say their findings shed light on the role of individual choices in the evolution of species and the growth of biodiversity. "Animals with nervous systems and brains have ...

Variation in women's X chromosomes may explain differences among individuals, between sexes

... the differences in traits among women and between males and females, in terms of both health and disease, ...s completely unique to women. The X chromosomes of males are all the same in this regard." Willard and study co-author Laura Carrel, Ph.D., of Penn State, r...

Scientists journey to southern Africa to unravel the secret world of elephant communication

...s. Suddenly, and for no apparent reason, the four males step away from the water and freeze in unison, as ...d their offspring," O'Connell-Rodwell notes. "Once males reach puberty, around age 12, they get kicked out and start traveling alone or forming small bachelo...

Maine Researchers Find Exceptions to Old Rules of Genetic Inheritance

...k who studied inheritance in flowering pea plants, males and females should pass the t haplotype to half th...nge twist to what Mendel might have predicted, the males pass the t haplotype to nearly 100 percent of their offspring (a phenomenon known as "transmission r...

To sea or not to sea: When it comes to salmon sex, size sometimes doesn't matter

...almost as likely to be a "winner" as the full-size males that are releasing their sperm in a competitive fr... at sea for the relative safety of freshwater, and males are more inclined to remain than females. This difference is related to the fact that reproductive s...

Oldest cranial, dental and postcranial fossils of early modern European humans confirmed

...urope. Given the presence of multiple individuals, males and females, adult and immature with cranial, dental and postcranial elements, the Mladec assemblage becomes the oldest directly dated substantial assemblage of modern human remains in Europe. ...

Of mice and men's (and women's) contraceptives

... in germ-line cells results in infertility in both males and females, according to a new study from researchers at the University of Pennsylvania School of Medicine. Norman Hecht, PhD, Professor of Human Reproduction in Penn's Center for Research in Reproduction and Women's Health, and colleagues say that ...

Scientists generate patient-specific stem cells, Science study says

...ailored to match the nuclear DNA of patients, both males and females of various ages, suffering from diseas... resulted from nuclear transfer with skin cells of males or females and oocytes from biologically-unrelated females. Other improvements over the last paper ...

SuperLigands - a database of ligand structures derived from the Protein Data Bank

...ailored to match the nuclear DNA of patients, both males and females of various ages, suffering from diseas... resulted from nuclear transfer with skin cells of males or females and oocytes from biologically-unrelated females. Other improvements over the last paper ...

Making Sure Sacred Sheep Don't Become Extinct

...He hopes to get samples from at least 50 different males to get a broad sampling of genetic diversity. If there were ever a need to totally regenerate the Navajo-Churro breed from the ARS collection, a backcrossing strategy could be used. In such a situation, Churro semen would be used to inseminate a ewe...

Mother birds increase progesterone to hatch females

...n feeding the next generation," says Correa. Since males disperse, the mother bird may adaptively bias her offspring to female so that plenty of females from one generation will be available to help raise the next generation. Although the finding is not of practical use in the near future for the poultry ...

Gov't Creates Gene Database of Normal Human Tissues

...harvested an average of 11 hours after death, from males and females of different ethnic groups, ranging from ages 3 months to 39 years old. The very large cDNA microarray they constructed has more than 42,000 detectors built into two chips using verified cDNA libraries upon which many other researchers c...

Scientists use manufacturing methods to reconstruct mastodon

...ome died of wounds inflicted by the tusks of other males during combat. The Buesching mastodon, in fact, appears to have been killed in a fight with another male mastodon and then butchered by humans. Fisher and a team of assistants also discovered a set of 30 mastodon footprints, believed to be the longe...

Certain fish have a special mating preference

...s shown that for some fish species, females prefer males with larger sexual organs, and actually choose them for mating. That does not exclude males with an average-sized sex organ, called a gonopodium. These fish out-compete the larger-endowed male...

IMF Launches World’s First DNA Database for Myeloma Patients

...s shown that for some fish species, females prefer males with larger sexual organs, and actually choose them for mating. That does not exclude males with an average-sized sex organ, called a gonopodium. These fish out-compete the larger-endowed male...

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