A NEWLY discovered gene could shed light on why some people develop as girls
even though they have a boy’s Y chromosome.
David Ornitz and his colleagues at Washington University Medical School in St
Louis, Missouri, engineered mice to lack a gene called Fgf9, which
makes fibroblast growth factor 9. They expected this to shrivel the mice’s
lungs, and it did—all 24 mice died at birth. But they were also surprised
to find that 10 male mice in the study had unexpectedly lost their manhood and
developed female genitalia. “The male sex organs had completely regressed,” says
Ornitz.
The…
