Cloning and expression of the chick p63 gene.

We have isolated a chick cDNA for p63, a member of the p53 transcription factor family. This cDNA encodes a protein of 582 amino acids for an alpha isoform in the C-terminal region, while lacking the N-terminal transactivation domain. The chick p63 gene is first expressed in the prospective cutaneous ectoderm at stage 6 and later in the developing epithelia. The p63 expression is intense in specialized epithelial structures, such as apical ectodermal ridge of the limb bud, epithelia of branchial arches and feather buds. Furthermore, we have found that the transcripts are detected in the interdigital epithelium, intersomite epithelium, and epaxial dermamyotome.