GeneAlert ... from UPI

FEWER PESTICIDES USED IN CHINESE GM RICE TRIAL

Genetically modified rice grown in Chinese field trials resulted in higher crop yields, reduced pesticide use and fewer pesticide-linked health problems. The study provides China and other nations with objective, research-based information about whether GM food crops can actually improve farmer welfare, according to study co-author Carl Pray at Rutgers University. The farmers grew the rice without help or advice from technicians, making all of their own decisions on whether to apply pesticides on both genetically modified insect-resistant rice and non-genetically modified rice. They based their decisions on observations of the severity of pest infestations, rather than on any prescribed dosages of pesticide, according to the study in Science. Researchers in China, as well as at Rutgers and the University of California, Davis, said use of the genetically modified rice enabled the farmers to reduce pesticide use by 15 pounds per acre, an 80 percent reduction compared with pesticide use by farmers using conventional rice varieties.

NEW METHOD TO PROBE GENETIC HYBRIDIZATION

The exchange of genes between species through interbreeding is a potentially important force in evolution, according to a U.S. study. Introgressive hybridization can facilitate evolutionary divergence and speciation by adding new genetic variation to populations. Until recently it has been thought to be rare, largely restricted to plants, and of little evolutionary significance.

Hybridization is most likely to occur in recently evolved species, yet these are the species in which it is most difficult to detect, owing to strong genetic similarity deriving from their recently shared ancestry, according to Princeton researcher Peter Grant. In the July issue of The American Naturalist, Grant and colleagues use microsatellite DNA data from Darwin's finches in the Galapagos archipelago to compare sympatric and allopatric genetic distances in pairs of species and find a striking tendency for a species to be more similar to a sympatric relative than to allopatric populations of that relative.

SLEEP GENE MUTATION DISCOVERED

Researchers at University of Wisconsin Medical School have identified a single gene mutation that impacts the amount of time fruit flies sleep. The Drosophila (fruit fly) gene, called Shaker, produces an ion channel that controls the flow of potassium into cells, a process that critically affects, among other things, electrical activity in neurons. A handful of recent studies suggest that potassium channels are also involved in the generation of sleep in humans, says lead author Dr. Chiara Cirelli, assistant professor of psychiatry at UW Medical School. The findings, published in Nature, offer the possibility of developing a new class of compounds that could affect potassium channels in the brain rather than other brain chemical systems targeted currently.

LACK OF DEFECT LOWER COLON CANCER RISK

Families with a certain type of hereditary colorectal cancer have a reduced cancer risk if they don't have a gene defect, find Minnesota researchers. Hereditary non-polyposis colorectal cancer -- HNPCC -- is a dominantly inherited syndrome characterized by significantly increased risks for colon cancer. Many experts currently use the term HNPCC synonymously with a hereditary DNA mismatch repair -- MMR -- a gene deficiency mechanism that corrects errors made during DNA replication. However, researchers found while group A families had increased incidences for cancers of the colorectum, endometrium, stomach, small intestine, and ureter, there was no increased incidence of cancer of the breast, lung, prostate or other sites. Group B families showed only a modest increase in the incidence of colorectal cancer, and no increase in the risk of other malignancies, according to the study in the Journal of the American Medical Association.

RACIAL IQ DIFFERENCES LARGELY GENETIC

A review of scientific evidence, some based on brain size, concludes race differences in average IQ are mostly genetic, say U.S. and Canadian researchers. Neither the existence nor the size of race differences in IQ are a matter of dispute, only their cause, according to J. Philippe Rushton of the University of Western Ontario and Arthur R. Jensen of the University of California at Berkeley. The findings, published in the June Psychology, Public Policy and Law pertain only to average differences. "Race differences show up by 3 years of age, even after matching on maternal education and other variables," said Rushton. "Therefore they cannot be due to poor education since this has not yet begun to exert an effect. That's why Jensen and I looked at the genetic hypothesis in detail. We examined 10 categories of evidence."

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(EDITORS: For more information on RICE contact Michele Hujber at 732-932-9559 or hujber@aesop.rutgers.edu. For HYBRIDIZATION, Carrie Olivia Adams at 773-834-0386 or coa@press.uchicago.edu. For SLEEP, Dian Land at 608-263-9893 or dj.land@hosp.wisc.edu. For COLON, Cathryn Stroebel at 507-266-0810. For IQ, J.P. Rushton at 519-661-3685 or rushton@uwo.ca.)