黑素皮质素受体1(MC1R)在不同毛色羊驼皮肤组织中的表达与定位研究

Expression and Immunolocalization of Melanocortin Receptor 1(MC1R) in Alpaca Skin with Different Coat Color

旨在通过研究黑素皮质素受体1(MC1R)在羊驼皮肤组织中的定位与表达,探讨其在羊驼毛色形成中的作用机制及与毛色的相关性。选用成年白色羊驼与棕色羊驼为研究对象,采用免疫组织化学方法及免疫印迹法(Western blotting),对MC1R在羊驼皮肤中的表达进行定位和定量分析。结果,(1)免疫组化结果显示,MC1R蛋白在白色和棕色羊驼皮肤表皮、毛囊周围外根鞘组织、毛乳头以及毛球周围都呈阳性着色。在棕色羊驼,阳性表达部位主要分布于毛球顶部及表皮,呈强阳性着色。在白色羊驼,阳性表达部位主要在外根鞘及表皮,毛球部表达呈弱阳性。MC1R在棕色羊驼皮肤组织中极显著表达(P<0.01)。(2)Western blotting结果显示,羊驼皮肤组织粗蛋白提取物中存在分子量约35ku与兔抗MC1R多克隆抗体发生免疫阳性反应的蛋白条带,且棕色羊驼平均蛋白表达量显著高于白色羊驼,差异极显著(P<0.01)。MC1R在羊驼皮肤组织中的定位与表达量的不同与羊驼毛色表型之间存在一定的相关性。

To explore the mechanism of coat color formation and the relationship between MC1R expression and coat color of alpaca,the expression and immunolocalization of MC1R in skin of alpacas with different coat color were analyzed.The adult white and brown alpaca were observed.Both immunohistochemistry and Western blotting methods were used to examine the expression and immunolocalization of MC1R in skins.The result showed that：（1） Immunohistochemistry results showed that MC1R positive immunoreactivity was prominently located at the epidermis,outer root sheath,the proximal hair bulb and follicular papilla.However,in brown alpaca skin,MC1R was prominently located at the epidermis and the proximal hair bulb with a strong staining.In white alpaca skin,MC1R was prominently located at the outer root sheath and epidermis,but it expressed with a weak staining in the proximal hair bulb.MC1R expression was higher in brown skin alpaca than that in white skin alpaca（P〈0.01）.（2） Western blotting results showed that the protein band in 35 ku extracted in crude protein of skin tissue responsed to MC1R polyclonal antibody in rabbit.MC1R protein expressed in different coat color skin and MC1R expression was higher in brown skin alpaca than that in white skin alpaca（P〈0.01）.It indicated that expression and immunolocalization of MC1R was related with the phenotype of coat color.