Researchers led by Professor Paul-Martin Holterhus of University Hospital in Kiel, Germany, have shown for the first time that testosterone leaves an irreversible molecular signature in cells and that might provide a far more sophisticated way to look at sex than just ascertaining the presence of the Y chromosome.
The U.S. and German scientists said their findings provide a platform for future work that may lead to improved counseling for individuals whose gender is ambiguous.
"Androgens have long lasting effects during certain sensitive stages of our genital development and this is probably true for other organs," Holterhus said. "It is currently increasingly accepted that the brain shows sex-specific development in response to presence or absence of testosterone. This affects sex specific behavior and probably modulates gender identity."
The study appeared in the online journal BMC Genomics.