MOUSE HOMEOBOX GENE DBX - SEQUENCE, GENE STRUCTURE AND EXPRESSION PATTERN DURING MIDGESTATION

Homeobox genes regulate multiple aspects of mouse development includin g the axial patterning in the central nervous system. Some of the more divergent members of this gene family are expressed in the anterior r egion of the central nervous system where the Hox genes are not expres sed. We previously reported the isolation of a mouse homeobox gene, Db x, from the forebrain. Here we describe its genomic structure, complet e cDNA sequence, characterization of the basal promoter and the expres sion pattern at different stages of the developing embryo. During earl y and mid-gestation, Dbx expression is restricted to the telencephalon , diencephalon, dorsal mesencephalon and spinal cord. At later gestati onal stages, Dbx expression continues in the dorsal mesencephalon and diencephalon, in which expression is more restricted than at the earli er stages. Dbx transcripts were also detected in the primitive cerebel lum. At all stages, the Dbx expressing regions contain a high proporti on of proliferating cells, suggesting a role for Dbx in patterning the central nervous system during embryogenesis.