摘要
The expression of six genes belonging to two different homeobox gene families was studied during skin morphogenesis of the mouse embryo. The first family include the Otx1 and Otx2 genes, both related to the orthodenticle Drosphila gene, while the second was represented by four member of theAntennapedia class HOX genes: Hoxc8 and three Hoxd genes (Hoxd9, d11 and d13). In situ hybridizations with 35S labeled antisense RNA probes were performed on head serial frontonasal sections, as well as entire embryo saggital and postnatal tail sections. The expression of these genes shows a differential spatio-temporal pattern along the cephalo-caudal axis. In 12.5-day embryo, the Otx2 gene expression is limited to the nasal epithelium and its associated glands, while the Otx1 transcripts are present both in nasal and facial integument, including hair vibrissa follicles. The Hoxc8 and two of theHoxd genes (Hoxd9 and d11) were respectively expressed in the dorsal and caudal skin, by 14.5 days of gestation. Furthermore, the Hoxd13 transcripts appear only 2 days after birth and are restricted to the hair matrix of the caudal pelage hair follicles. Taken together, these observations strengthen the hypothesis that different homeobox gene families specify the regional identity of the skin in the cephalic and body regions.