EXPRESSION OF VERTEBRATE HOMOLOGS OF THE DROSOPHILA MSH GENE DURING EARLY CRANIOFACIAL DEVELOPMENT

It has become clear that many gene products containing the homeodomain, a helix-turn-helix DNA motif, are involved in establishing the initial pattern of differentiation during development. The msh family of homeobox containing genes is just being characterized in vertebrate embryos where it is widely expressed during craniofacial development. msh transcripts accumulate in the dorsal neural tube, presumptive neural crest, and many tissues in the craniofacial region during a period when tissue patterning is occurring, but not after cytodifferentiation. Based on these observations, it is likely that this group of homeobox containing genes is involved in the development and evolution of the craniofacial region.