dMi-2, a hunchback-interacting protein that functions in Polycomb repression

Early in Drosophila embryogenesis, gap gene products directly repress trans cription of homeotic (HOX) genes and thereby delimit HOX expression domains . Subsequently, Polycomb-group proteins maintain this repression. Currently , there is no known molecular Link between gap and Polycomb-group proteins. Here, dMi-2 is identified as a protein that binds to a domain in the gap p rotein Hunchback that is specifically required for the repression of HOX ge nes. Genetic analyses show that dMi-2 participates in both Hunchback and Po lycomb repression in vivo. Hence, recruitment of dMi-2 may serve as a link between repression of HOX genes by Hunchback and Polycomb proteins.