Human Hox-4.2 and Drosophila deformed encode similar regulatory specificities in Drosophila embryos and larvae.

Department of Molecular Biophysics and Biochemistry Yale University, New Haven, Connecticut 06511.

Within the serial array of vertebrate homeobox genes in the Hox complexes, it is possible to define a subgroup that is structurally homologous to the Drosophila homeotic gene Deformed (Dfd). We wished to test whether a vertebrate Dfd-like protein could substitute for any of the regulatory functions of the Dfd protein in Drosophila embryos, including its ability to transcriptionally activate the Dfd transcription unit. A fusion gene consisting of a heat shock promoter attached to the human Hox-4.2 gene was introduced into the Drosophila genome, and its regulatory and developmental effects were assayed after heat shock. In developing embryonic and larval cells, we find that human Hox-4.2 specifically activates ectopic expression of the endogeneous Dfd transcription unit and phenocopies a dominant mutant allele of Dfd. Thus, human Hox-4.2 can specifically substitute for a normal regulatory function of its Drosophila homolog, Dfd.

PMID: 1979526 [PubMed - indexed for MEDLINE]