Flies with inner ears?

In a study which suggests that genetic mutation was not necessarily the primary evolutionary force producing morphological change in mammals, researchers report in the September issue of Developmental Cell that the Drosophila Hmx gene partially rescued the development of the mouse inner ear, revealing that the gene could direct the development of an organ it does not even possess.

When thinking of how new traits evolve, people have mainly focused upon mutations in protein sequences said Thomas Lufkin, of the Genome Institute of Singapore, and senior author of the Developmental Cell study. "But, an equal possibility is that, instead of the gene sequence mutating, the same gene can acquire new expression domains," Lufkin told The Scientist.

This possibility became apparent as Lufkin, lead author Weidong Wang, and their colleagues began to study a family of homeobox genes termed Hmx. Drosophila has a single Hmx gene, termed DHmx, whose expression pattern ...