0006-291X28042001Feb02Biochem Biophys Res CommunIncrease in expression of the homeobox gene, GBX1, in retinol-induced epidermal mucous metaplasia.105510611055-61Using a degenerate RT-PCR-based screening method, we isolated the homeobox gene, Gbx1, from the shank skin of 13-day-old chick embryos. By in situ hybridization analysis we showed that the Gbx1 was expressed in the epidermis of the skin and the mucous epithelium of the intestine, and that among many homeobox genes isolated, expression of the Gbx1 strongly increased in the epidermis when the skin was cultured with 20 microM retinol, which induces epidermal mucous metaplasia. The Gbx1 expression in the epidermis was increased by interaction with the retinol-pretreated dermal fibroblasts, resulting in mucous metaplasia. These results suggest that the Gbx1 regulates the differentiation and transdifferentiation of the epithelium and controls the morphology of the epithelium. We isolated the chick Gbx1 cDNA clones. The amino acid sequences in homeodomain and its downstream encoded by human and chick Gbx1 cDNA were almost the same, but those upstream of the homeodomain were rather different.Copyright 2001 Academic Press.ObinataAADepartment of Physiological Chemistry, Teikyo University, Sagamiko, Kanagawa, 199-0195, Japan.AkimotoYYOmotoYYHiranoHHengGENBANKAB050015Journal ArticleResearch Support, Non-U.S. Gov't