By targeting the sonic hedgehog (Shh) gene, geneticists Michel Milinkovitch and Rory Cooper of the University of Geneva in Switzerland altered embryonic chickens to grow feathers instead of scales on their usually squamous feet.
And the alteration is permanent. Once hatched, the chicken’s unusually feathery feet will stay that way for life.
Tweaking Just a Few Genes Transforms Scales Into Feathers
I think there was a time when Robert T. Bakker was talking about reverse engineering dinos from chickens..