Conservation of neurogenic genes and mechanisms.

Reports from the past year have demonstrated that neural basic helix-loop-helix genes and LIM homeobox genes contribute to neuronal subtype specification in vertebrates and invertebrates, that Notch signaling specifies cell fates in the developing vertebrate inner ear, and that the organization of the central nervous system into three columns is shared by vertebrates and invertebrates. These findings pave the way for future work that will help to establish the extent to which these similarities represent evolutionary conservation.