Gender Divide: Gene Expression Differs in Males and Females

Article excerpt

There are far more biological differences between males and females than meet the naked eye. A new study suggests that the two sexes vary in the amounts of proteins produced by thousands of genes--information that could explain why some diseases strike men and women differently.

"We're certainly conscious that sex can have an effect on numerous diseases," says Thomas Drake of the University of California, Los Angeles. For example, he points out, autoimmune diseases such as lupus disproportionately strike women, whereas men are more likely to have autism and some other mental disorders.

Ongoing studies by Drake and his colleagues are investigating the root causes of diabetes, obesity, and related metabolic diseases. To see how gender interacts with genetics to affect those diseases, Drake and his colleagues worked with 165 male and 169 female mice. Using samples of four tissues--liver, fat, muscle, and brain--the researchers measured production of the proteins encoded by each of 23,000 of the animals' genes.

"We were immediately struck by the differences in gender" Drake says. "They went way beyond what we were expecting."

The team found that in liver, fat, and muscle tissue, males and females differently expressed 55 to 72 percent of the genes studied. The brain had the smallest differences in gene expression between the sexes, occurring in only about 15 percent of the genes. …