A newly discovered genetic abnormality that appears to prevent some men from conceiving children could be the key for developing a male contraceptive, according to University of Iowa researchers reporting their findings in the April 2 online edition of the American Journal of Human Genetics.
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Although female oral contraceptives were developed over 40 years ago and have proven very effective for family planning, no similar pharmacological contraceptive has been developed for males. Surveys conducted by the Medical Research Council Reproductive Biology Unit in the United Kingdom, suggest that men would be willing to use a pharmacological contraceptive if one was available. Presently the only contraceptives available for men are condoms or a vasectomy.
Read more at www.labspaces.net |
Gene in fruit flies may engage in ‘genetic warfare’ that causes speciation |
A newly identified gene in fruit flies may drive the creation of new species, revealing how internal genetic environments may be just as important as external factors when it comes to speciation. The new work lends evidence to a hotly debated idea in evolutionary biology.
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“Conventionally, evolutionary biologists thought that speciation involved adaptation to the external environment, but these results suggest that adaptation to the internal genomic environment also sometimes plays a role,” explains study author Nitin Phadnis of the University of Rochester in New York. |
“I think it’s great,” comments researcher Mohamed Noor of Duke University in Durham, N.C. “It represents a dramatic change in the context of the field.” |
| To many scientists, genome-mingling is what defines a species ” members within a single species can swap genetic material frequently and easilySee more at www.sciencenews.org |
Scientists, including Harvard Medical School’s Jack Szostak, expect an announcement within three to 10 years from someone in the now little-known field of “wet artificial life” that they have created the first cell of synthetic life ” made from the basic chemicals in DNA. Meanwhile at the J. Craig Venter Institute , a team of scientists has refined its method for building a synthetic genome. In a paper in the Proceedings of the National Academy of Sciences, the researchers demonstrate that they can assemble dozens of snippets of DNA into a complete Mycoplasma genitalium genome in just one step in yeast. |
| “Genome assembly in yeast, as we described it, is accomplished not by
the addition of overlapping segments one at a time, but rather by
co-transformation of 25 different pieces at once, |
“Thus, large DNA
molecules can be assembled much more rapidly from synthetic or
naturally occurring sub-fragments than with any other system described
previously.”
See more at www.dailygalaxy.com |
The Caterpillar and Alice looked at each other for some time in silence: at last the Caterpillar took the hookah out of its mouth, and addressed her in a languid, sleepy voice. ‘Who are YOU?’ said the Caterpillar. This was not an encouraging opening for a conversation. Alice replied, rather shyly, ‘I ” I hardly know, sir, just at present.’
The answer might seem simple, even trivial: name, rank, serial number, family connections, occupation, and so forth. But there is more to the caterpillar’s contemptuous question than meets the eye, for biologists no less than for a philosophically inclined insect. Who are we? It turns out that the business of being a “self” is more fraught than cultural tradition and subjective experience tell us |
| The deepest, most private recesses of our genome might seem, if not sacrosanct, at least the inner sanctum of our “selves.” |
| But consider this: More than four times as much space in the human genome is occupied by “endogenous retroviruses”See more at chronicle.com |
Men with a common gene variation for “bonding” hormone report more marital strife |
There’s news for women who want a man who bonds instead of a
James Bond: Scientists have identified a common genetic variation that appears
to weaken a man’s ability to emotionally attach to one partner. |
The study, to appear in the Proceedings of the National Academy of Sciences, is the first to
try to examine whether a hormone that encourages monogamy in animals plays a similar
role in male humans. Before getting ideas about a DNA-fidelity test, though, women
should consider that the study wasn’t designed to determine how much ” or even
whether ” the gene in question is responsible for monogamy in humans. |
“We can’t with any accuracy predict effects on behavior,”
says Hasse Walum of the Karolinska Institute in Stockholm. “A lot of different things
determine how happy you will be in a relationship.” |
Have you ever wondered why you can’t get off the couch and exercise ” despite paying for an expensive gym membership, despite your New Year’s resolutions, even despite the doctor’s scolding at your last check-up? Turns out that your inertia may be coded right into your genes. |
| Based on some intriguing, preliminary studies in animals, J. Timothy Lightfoot, a kinesiologist, and his team at University of North Carolina, Charlotte, suggest that genetics may indeed predispose some of us for sloth. Using mice specially bred and selected according to their activity levels, Lightfoot identified 20 different genomic locations that work in tandem to influence activity levels in mice ” specifically, how far the animals will run |
| genes may affect either the way muscles work ” perhaps causing them to use energy more efficiently and preventing fatigue ” or some higher-order biochemical circuit in the brain, such as levels of the neurotransmitters dopamine or serotoninSee more at www.time.com |
Growing old may not be mandatory after all. Failing eyesight, loosened teeth and greying hair could be driven by regulatory genes that determine when it is time to shuffle off our mortal coil, rather than being indicators of the ravages of age. |
American scientists have challenged the conventional view that ageing is caused by wear and tear ” like rust on an old car. Instead, they suggest specific genetic instructions drive the process. If they are right, science might one day find ways of switching the signals off and halting or even reversing ageing. |
Researchers at Stanford University Medical Centre raised questions about the conventional theory of ageing on the basis of observations in the animal world. Stuart Kim, a professor of developmental biology, said: “Everyone has assumed we age by rust. But how do you explain animals that don’t age?” Some tortoises lay eggs at the age of 100, there are whales that live to be 200 and clams that make it past 400 years, he said. See more at www.independent.co.uk |
| Though you might take mild offense at being compared to a fly, a new scientific discovery may provide a clue as to why humans and animals alike experience insomnia. A new genetic mutation found in flies can cause 80% less sleep than normal flies, forcing the flies to get by with much less sleep. |
| The mutation, now dubbed Sleepless, suggests that at our most basic
level, sleep is caused by a slowdown in certain neurons. And according
to Amita Seghal, a neurobiologist at the University of Pennsylvania in
Philadelphia, who led the new study, an inability to control these
neurons may be the cause of restless nights. |
| “When you’re having a bad night of insomnia you do have the need to
sleep, but you’re not able to,” she says. “That might be what’s going
on with these animals.” |
| normal fly manages to sleep for around 12 hours a day, those
flies with a broken Sleepless only get one or two hours; however they
don’t realize they’ve lose sleep.See more at www.dailygalaxy.com |
It’s clear that there’s a specific set of genes responsible for brain development when you’re in the womb, and that those genes affect your ability to learn later on. But now a group of researchers in the U.S. and Canada have identified those genes. And their discovery could represent the first step in tweaking brain development. It’s possible that that knocking out some of those genes or adding extra copies of them to a developing baby could result in the tailor-made human minds of Brave New World: Some will be born to develop cutting-edge technologies, and others to be slow-witted and compliant. Published this weekend in PLoS Genetics, the study is extraordinary not just because of its futuristic implications, but because of the cool new super-rapid system the researchers used to identify which genes are active during brain development. The technique is called RNA interference, or RNAi: See more at io9.com |
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