MOLECULAR-CLONING AND EVOLUTIONAL ANALYSIS OF A MAMMALIAN HOMOLOG OF THE DISTAL-LESS-3 (DLX-3) HOMEOBOX GENE

We have cloned and sequenced a cDNA encoding the mammalian homologue o f Disral-less 3 (Dlx-3) from a rat embryonic brain cDNA library. The p rimary structure of rat Dlx-3 showed a cDNA with an open reading frame of 290 amino acids with a molecular weight of 31 kDa harboring a home odomain sequence characteristic of the Distal-less homoeobox gene. In addition to the highly conserved homeodomain sequence, we newly found the consensus motifs in the N-terminal and C-terminal region, which we re specifically conserved among Distal-less members of different speci es. Phylogenetic analysis of the Distal-less homeodomain sequence also showed a possible association between the sequence similarities in th e homeodomain and the spatial specifications of homeobox genes express ed in the developing central nervous system.