DURHAM, N.C. -- Scientists have discovered an elusive, mutated gene named for the Greek goddess, Aphrodite Kallipygos, that causes certain sheep to have unusually big and muscular bottoms. They hope the genetic mutation will illuminate how muscle and fat are deposited in these animals and possibly in humans.
The discovery is especially exciting, said the researchers, because the unusual gene has evaded all the traditional means of detection for nearly a decade. In fact, the gene appears to represent one of numerous stealth genes, called "imprinted," that have yet to be discovered but which could produce a wide range of diseases.
Researchers from the U.S. Department of Agriculture and Duke University Medical Center discovered a gene called "callipyge," (pronounced cal - ah - PEEJ) meaning "beautiful buttocks" in Greek, because the sheep have large, muscular bottoms with very little fat. Such an attribute could prove beneficial in breeding these sheep because it enables them to convert food into muscle 30 percent more efficiently than normal sheep. Moreover, the gene could explain specific processes that give rise to obesity and fat metabolism, said Randy Jirtle, Ph.D., professor of radiation oncology at Duke and co-author of the study.
"These sheep are, in effect, pumping iron without lifting weights," explained Jirtle. "They are converting food into muscle in their hind regions, instead of converting food into fat."
Results of the study, funded by the USDA and the National Institutes of Health, are published in the October 2002 issue of Genome Research.
Excited as they are to have unearthed the gene behind the big-bottomed sheep, the scientists say their discovery has equally dramatic implications for mining the human genome. The callipyge gene appears to be among a rare subset that eludes traditional methods of identification and mapping, said USDA geneticist Brad Freking, Ph.D., lead investigator o
Contact: Rebecca Levine
Duke University Medical Center