The murine and Drosophila homeobox gene complexes have common features of organization and expression
Graham, A.; Papalopulu, N.; Krumlauf, R.
Cell 57(3): 367-378
1989
ISSN/ISBN: 0092-8674 PMID: 2566383 DOI: 10.1016/0092-8674(89)90912-4
Accession: 007918112
In situ hybridization analysis of mouse embryos shows the seven members of the Hox-2 complex to be differentially expressed in the central and peripheral nervous system and in mesodermal derivatives (somites and lung). Beginning at the 5- end of the cluster, each successive gene displays a more anterior boundary of expression in the central nervous system. A gene's position of the Hox-2 cluster therefore reflects its relative domain of expression along the anteroposterior axis of the embryo, a feature observed with Drosophila homeotic genes. Sequence comparisons of the Hox-2 cluster with other mouse and Drosophila homeobox genes have defined subgroups of related genes; in the mouse there are four clusters related by duplication and divergence. Alignment shows a clear relationship among genes in the mouse and Drosophila complexes, based on relative position, sequence identity, and domains of expression along the rostral-caudal axis. Our results argue that these complexes arose from a common ancestor, present before the divergence of lineages that gave rise to arthropods and vertebrates.