Two regulatory genes, cNkx5 - 1 and cPax2, show different responses to local signals during otic placode and vesicle formation in the chick embryo. - Herbrand,H.; Guthrie,S.; Hadrys,T.; Hoffmann,S.; Arnold,H.H.; Rinkwitz-Brandt,S.; Bober,E. (Development, 1998)