Gene manipulation in mice and bats shows evolution of limb length

In evolutionary terms bats and mice are separated by millions of years.

An MD Anderson team led by Dr Richard Behringer successfully switched the mouse Prx1 gene regulatory element with the Prx1 gene regulatory region from a bat – the resulting transgenic mice displayed abnormally long forelimbs.

While forelimb length is just one of several key morphological changes that occurred during the evolution of the bat wing, this unprecedented finding demonstrates that evolution can be driven by changes in the patterns of gene expression, rather than solely by changes in the genes, themselves.

Dr. Behringer describes the significance of his finding as such: “Darwin suggested that “successive slight modifications” would ultimately result in the evolution of diverse limb morphologies, like a hand, wing, or fin. The genetic change we engineered in mice may be one of those “slight modifications” to evolve a mammalian wing.”

Elaine Warburton