Int. J. Dev. Biol. 49: 885 - 890 (2005)

https://doi.org/10.1387/ijdb.052037ao

Vol 49, Issue 7

Expression of Hex during feather bud development

Open Access | Developmental Expression Pattern | Published: 1 September 2005

Akiko Obinata*^,1 and Yoshihiro Akimoto

¹Department of Physiological Chemistry, Faculty of Pharmaceutical Sciences, Teikyo University, Sagamiko, Kanagawa, Japan and ²Department of Anatomy, Kyorin University School of Medicine, Mitaka, Tokyo, Japan

Abstract

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.

Keywords

Hex, homeobox gene, feather placode, Wnt, feather bud development