Mice Given Bat-like Forelimbs

Molecular Evolution: Mice Given Bat-like Forelimbs Through Gene Switch A research team led by Dr. Richard Behringer at MD Anderson Cancer Center reports that they have successfully switched the mouse Prx1 gene regulatory element with the Prx1 gene regulatory region from a bat — and although these two species are separated by millions of years of evolution — the resulting transgenic mice displayed abnormally long forelimbs.