Abstract:

Abstract:The histological characteristics, distribution and variation discipline of epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) during skin′s development of goat fetus were studied with histological methods and immunohistochemistry. The results showed that the epidermis formed at the embryonic 6th week, and then the thickness increased gradually because of transition from simple epithelium to stratified epithelium, and decreased after the 15th week. The structure of dermis occurred at the 10th week, and the derivates in dermis appeared after the 11th week. As the process of prenatal development, all structures of skin matured gradually. Low expression of EGF and EGFR could be observed at the 6th week. Afterwards, the expression of EGF and EGFR increased as growth. Before the 11th week, EGF positive reaction mainly located in cytoplasm of basal layer cells of epidermis, hair follicular epithelia cells and fibroblasts, and EGFR mainly located on cell membrane of these cells. From 11th to 16th week, the expressional range of EGF and EGFR extended from basal layer cells, prickle cells, hair follicular epithelia cells and fibroblasts to vascular endothelial cells, epithelial cells of sweat gland and arrector pili muscle. EGF mainly distributed in cytoplasm of these cells, and EGFR were also located on membrane of these cells. From 17th week to birth, EGF mainly located in basal layer cells and hair follicular epithelia cells as the skin thinned, the positive intensity continued to increase. The expressed amount of EGF and EGFR trended to increase during the whole development stage just accompanied by a hysteresis in expression of EGFR. There were extreme significant correlations between expressed amount of EGF and EGFR. The results demonstrated that EGF and EGFR played important roles in the development of skin and its derivates.