Abstract:

【Objective】 The aim of this experiment is to study the expression and immunolocalization of endothelin receptor A and B in sheep skin, to compare the expression quantity in different colors, and to explore the function of EDNR in the process of coat color formation.【Method】The mRNA and protein expression level of EDNR in sheep skin of different colors were examined by real-time quantitative PCR , western blot and immunohistochemistry.【Result】 The EDNR A and B genes were expressed in sheep skin reliably. The expressive quantity of EDNR A gene in the black sheep skin tissue was 1.2649 times than that in white one, and the same quantity of EDNR B gene in black was 1.8248 times than that in white. By western blot there appeared EDNR proteins in total protein extracted from skin tissue, and there was no significantly difference in EDNR A between black and white skin (P＞0.05), but there was higher level of EDNR B in black skin than that in white one (P＞0.05). Immunohistochemistrial results showed that there was an expression of EDNR protein in black and white epidemic and hair follicle sheath cells of black and white skin tissue. Furthermore, by optical density analysis, the expression of EDNR A was higher in every cell of black skin than that in white one. There was also a higher level of EDNR B in dermal papilla cells and epidemic cells of black skin tissue than that in white ones (P＞0.05). However, there was no significant difference of EDNR B in hair follicle sheath cells of black and white skin tissue. 【Conclusion】 Results showed that EDNR is involved in the process of coat color formation, and a difference in the functional efficiency of the two receptors is existed.

Key words: EDNR, sheep, skin, immunohistochemistry, Western blot, QRT-PCR