Life Sciences and Chemistry

In an unexpected discovery, a team led by Northwestern University scientists has become the first to show that progesterone, a hormone usually associated with female reproduction and maternal behavior, plays a key role in regulating male aggression toward infants in mice. Testosterone, not progesterone, had been thought to be responsible.

The researchers found that the absence of progesterone’s actions reduced aggression while promoting positive paternal behavior. The findings, to be p

The first laboratory population study of genetically modified mosquitoes identifies issues that need to be faced in the task of turning mosquitoes from disease carriers into disease fighters.

Scientists from Imperial College London report in Science today that populations including genetically modified mosquitoes quickly lose their test marker gene when they are bred with unmodified mosquitoes.

The scientists say their results have several lessons for further work on developing GM m

Researchers from the University of Pennsylvania and the University of Sheffield report in the Feb. 21 issue of Science that they have created tree-like molecules that assemble themselves into precisely structured building blocks of a quarter- million atoms. Such building blocks may be precursors to designing nanostructures for molecular electronics or photonics materials, which “steer” light in the same way computer chips steer electrons.

Virgil Percec, the P. Roy Vagelos Chair and Profes

B cell chromatin study strikes physiological chord

Some cells sing with the chorus, while others unwittingly achieve fame on their own. The immune system’s B cell is a true diva that spends its early days preparing for the ultimate audition. Its repertoire of possible antibodies to invading microbes totals 50 million. For the immune system, this repertoire means the difference between destroying a potentially lethal antigen or not.

Since the late 1970s, the genes for makin

Greater insight into human brain disease may emerge from studies of a new genetic mutation that causes adult fruit flies to develop symptoms akin to Alzheimer’s disease.

“This is the first fruit fly mutant to show some of the outward, physical manifestations common to certain major human neurodegenerative diseases,” said principal investigator Michael McKeown, a biology professor at Brown University.

A research team found the mutation in a gene they named “blue cheese.” Reporting i

Increasing hormone causes increase of appetite, eating

Researchers at Oregon Health & Science University (OHSU) have identified a key hormone involved in appetite control and demonstrated its effect on the brain. Scientists have shown that the hormone, called ghrelin, activates specialized neurons in the hypothalamus involved in weight regulation. The research involved scientists at several collaborating institutions, including: Yale Medical School, Baylor College of Medicine, the Uni