Male, female fat cells different in mice

DALLAS, May 18 (UPI) -- Genes dictate if fat is stored on belly or hips -- in particular, gender genes, U.S. researchers said.

Researchers at the University of Texas Southwestern Medical Center in Dallas, who studied mice say they were surprised to find major differences between male and female fat cells.

"We found that out of about 40,000 mouse genes, only 138 are commonly found in both male and female fat cells," senior author Dr. Deborah Clegg said in a statement. "This was completely unexpected. We expected the exact opposite -- that 138 would be different and the rest would be the same between the sexes."

The study, published in the International Journal of Obesity, also found male mice on a high-fat diet gained more weight and had more highly inflamed fat tissue -- especially belly fat -- than female mice eating the same diet.

However, in the female mice whose ovaries had been removed -- a condition similar to human menopause -- put on the high fat diet, weight gain was greater and more likely to be in the belly.

"Although our new findings don't explain why women begin storing fat in their bellies after menopause, the results do bring us a step closer to understanding the mechanisms behind the unwanted shift," Clegg said.