The homeodomain gene Xenopus Distal-less-like-2 (Xdll-2) is regulated by a conserved mechanism in amphibian and mammalian epidermis.

Xenopus Distal-less-like-2 (Xdll-2) is a gene encoding a homeodomain protein expressed predominantly in the epidermis of frog embryos. We report here that this epidermal expression is specified by a regulatory 5' flanking DNA region located within 933 bp of the start of transcription. This regulatory DNA also confers upon a globin reporter gene calcium-inducible expression in cultured murine keratinocytes and induction-dependent repression in frog ectodermal cells treated in vitro with activin A. These results reveal a new example of phylogenetically conserved, tissue-specific transcriptional regulation of a homeodomain gene.