Men's genes are from Venus and women's are from Mars

GENETICS

New research from the University of California at Los Angeles shows that many genes behave differently in females than in males, possibly explaining gender differences in disease rates and drug reactions. The investigators examined 23,000 genes from brain, liver, fat, and muscle tissues of 169 female and 165 male mice using genetic profiling tools. Measuring genetic expression, the process by which cells convert genetic instructions into proteins, they identified differences in expression levels in more than half of these genes. ``Whatever creates these differences between the sexes has a pervasive effect on the majority of genes in the body, at least in the tissues we looked at. These aren't tissues from the ovaries and testes, which are obviously different. They're the ones that do the basic work of the body," said UCLA pathologist and co-author Thomas Drake. In the liver, for example, the researchers found that genes known to affect drug metabolism behave differently in the sexes, possibly explaining why men and women often respond differently to the same drug. Many of the genes showing gender bias also relate to processes that influence common diseases.

BOTTOM LINE: Gender differences in the amounts of proteins that genes produce might explain why men and women react differently to drugs and many diseases.

CAUTIONS: The differences in genetic expression levels measured were statistically significant, but their significance biologically and for humans has not yet been determined.

WHAT'S NEXT: The researchers want to determine what factors cause these gender differences.

WHERE TO FIND IT: Genome Research, August 2006

ELIZABETH DOUGHERTY

CANCER

Fungus from a toxic lake may lead to a treatment

A therapy for cancer could come from one of the most toxic and contaminated waters on the planet. The Superfund site at Berkeley Pit Lake in Butte, Mont. -- an abandoned copper mine now contaminated with toxic metals -- is mostly devoid of life, but it is home to millions of microbes especially adapted to extreme conditions. Researchers have found that one of these microbes, a fungus, produces a chemical that kills ovarian cancer cells -- at least in a petri dish. Andrea A. Stierle of the University of Montana and her colleagues discovered the fungus and isolated the new anticancer compound, called berkelic acid. ``We tend to be interested in grizzly bears and orchids," said Stierle. ``Sometimes it's the microbial populations that have tremendous importance, and we often overlook them."

THE BOTTOM LINE: A fungus living in water contaminated by waste from a copper mine produces a chemical that shows promise fighting cancer.

WHAT'S NEXT: The researchers will share their finding with pharmaceutical companies, hoping that the companies will be interested in turning the compound into a drug.

CAUTIONS: Many steps still lie ahead before the compound, so far only tested in a lab, can become an anticancer drug. It could eventually prove to be too toxic for humans.

WHERE TO FIND IT: Journal of Organic Chemistry, July 7, 2006.

NAILA MOREIRA

BIODIVERSITY

Bird extinctions happening faster than thought

By the end of this century , human activity may drive 12 percent of the world's bird species to extinction, according to a new study, which found the bird extinction rate to be four times higher than previously believed and likely to increase dramatically. There are approximately 10,000 known bird species, and an estimated 130 of those have become extinct since 1500 , yielding an extinction rate of roughly one species every four years . The study, which took into account the continual identification of recently extinct species from skeletal remains and counted many missing species that have not yet been declared extinct, estimated that one species is lost every year . Human efforts to protect birds in recent decades have helped mitigate losses, but habitat destruction, invasive species, and climate change will greatly overwhelm such efforts, according to the study's authors. The research, the most detailed look yet of extinction rates in any comparably sized group of organisms, is ``an excellent baseline for considering the problem of extinction for all plants and animals," said Peter H. Raven , director of the Missouri Botanical Garden and a co-author of the study. ``The more we know, the better job we can do in saving them."

BOTTOM LINE: The rate of extinction in birds, one of the most heavily studied groups of organisms, appears to be four times higher than previous estimates, suggesting that humans may have a greater impact on global rates of biodiversity loss than previously believed.

CAUTIONS: Predictions on the loss of biodiversity have not always proven true. Raven said future projections in the study are difficult to substantiate.

WHAT'S NEXT: Raven and his colleagues will continue to refine their predictions on the extinction rate of birds and catalog new plants and animals to better understand extinction rates in other organisms.

WHERE TO FIND IT: Proceedings of the National Academy of Sciences, July 18, 2006

PHIL MCKENNA