nessy, an evolutionary conserved gene controlled by Hox proteins during Drosophila embryogenesis

From a library of DNA fragments associated with Ultrabithorax protein in vi vo, we have isolated nessy, a new Drosophila gene that encodes a putative t ransmembrane protein conserved in evolution from Caenorhabditis elegans, to human. Zygotic expression occurs transiently in mesectodermal cells at gas trulation, proceeds in mesoderm and endoderm lineages during germ band move ments and becomes then restricted to anterior and posterior domains in the visceral mesoderm. The Hox proteins Ultrabithorax, Antennapedia and Abdomin alA are likely acting simultaneously to repress nessy in the other parts of the visceral mesoderm. (C) 1999 Elsevier Science Ireland Ltd. All rights r eserved.