The Murine Homeobox Protein Hox 1.1 Is Differentially Expressed in Embryonal Mesoderm and Ectoderm

Abstract

Structural conservation is usually indicative of functional conservation. If this were also true of developmental control genes then the isolation of sequences homologous to developmental control genes of Drosophila could lead to the identification of genes with a related function in the mammalian genome. Indeed, based on this hypothesis, several candidates for mammalian developmental control genes have been identified. Undoubtedly most effort has gone into delineating the possible role of murine homeobox genes. At least 18 members of the Hox multigene family have been found, most of which are located on mouse chromosomes 6 and 11 (see Martin et al. 1987 for references and nomenclature). Another class of putative control gene is characterized by a common finger motif, a structure first suggested for the Xenopus transcription factor TFIIIA (Miller et al. 1985; for review see Klug and Rhodes 1987). Murine finger containing genes have been identified and individual members of this family have been shown to be specifically active in developing and adult neurons (Chowdhury et al. 1987; K. Chowdhury et al., submitted). Finally, a candidate for a third class of murine developmental control gene (Pax) bears a high degree of homology to Drosophila paired box (U. Deutsch et al., submitted). This conserved element is present in Drosophila segmentation genes such as paired, gooseberry proximal and gooseberry distal (Bopp et al. 1986; Cote et al. 1987).