Obinata Akiko, Akimoto Yoshihiro
Department of Physiological Chemistry, Faculty of Pharmaceutical Sciences, Teikyo University, Sagamiko, Kanagawa, Japan.
Int J Dev Biol. 2005;49(7):885-90. doi: 10.1387/ijdb.052037ao.
We studied proline-rich divergent homeobox gene Hex/Prh expression in the dorsal skin of chick embryo during feather bud development. Hex mRNA expression was first observed in the dorsolateral ectoderm and mesenchyme at 5 days, then in the epithelium and the dermis of the dorsal skin before placode (primordium of feather bud) formation and then was restricted to the placode and the dermis under the placode. Afterward, Hex expression was seen in the epidermis and the dermis of the posterior region of short bud. In accordance with Hex mRNA expression in the placode, Hex protein was observed in the epidermis as well as in the dermis of the placode. Immunoelectron microscopic study indicated that the protein located both in the nuclei and cytoplasm of the epidermis and the dermis at the short bud stage. The Wnt signaling pathway plays an essential role in the early inductive events in hair (Wnt3a and 7a) and feather (Wnt7a) follicles. The pattern of Hex expression in the epidermis was similar to that of Wnt7a, while little, if any, expression of Wnt7a was detected in the dermis under the placode or the dermis of the short bud compared with that of Hex, suggesting that Hex plays an important role in the initiation of feather morphogenesis.
我们研究了富含脯氨酸的分歧型同源框基因Hex/Prh在鸡胚羽毛芽发育过程中背部皮肤中的表达。Hex mRNA表达在第5天首次在背外侧外胚层和间充质中观察到，然后在羽基板（羽毛芽原基）形成前在背部皮肤的上皮和真皮中表达，随后局限于羽基板和羽基板下方的真皮。之后，在短芽后部区域的表皮和真皮中可见Hex表达。与羽基板中Hex mRNA表达一致，在羽基板的表皮以及真皮中观察到Hex蛋白。免疫电子显微镜研究表明，在短芽阶段该蛋白位于表皮和真皮的细胞核及细胞质中。Wnt信号通路在毛发（Wnt3a和7a）和羽毛（Wnt7a）毛囊的早期诱导事件中起重要作用。Hex在表皮中的表达模式与Wnt7a相似，而与Hex相比，在羽基板下方的真皮或短芽真皮中几乎未检测到Wnt7a表达，这表明Hex在羽毛形态发生起始中起重要作用。
