中文摘要：

目的观察9头健康牦牛犊牛睾丸结构特征及细胞外基质相关蛋白的分布特点。方法采用组织化学染色和透射电镜技术,观察睾丸显微及超微结构特点,免疫组织化学SP法及IPP图像分析技术,研究层黏连蛋白（LN）、Ⅳ型胶原（ColⅣ）和硫酸乙酰肝素糖蛋白（HSPG）的分布特征。结果睾丸生精上皮由Sertoli细胞和生殖母细胞构成1～2层,未形成空腔。电镜下,Sertoli细胞异染色质丰富,相邻Sertoli细胞胞膜下分布有典型外质特化与肌动蛋白丝形成的胞膜下纤维束;生殖母细胞较大,胞质丰富。免疫组织化学显示,LN、ColⅣ和HSPG在生精小管基膜和肌样细胞表达较弱,LN在生殖母细胞内的表达量显著低于ColⅣ和HSPG（P〈0.05）,而在Sertoli细胞及Leydig细胞均无表达;ColⅣ和HSPG在Sertoli细胞均为强阳性表达;HSPG在Leydig细胞的表达量显著高于ColⅣ（P〈0.05）。结论牦牛犊牛生精上皮以幼稚型Sertoli细胞为主,Leydig细胞处于胚胎型向成熟型过渡时期;细胞外基质（ECM）相关Ⅰ及Ⅳ型Col、LN及HSPG的分布适应于其在高原低氧环境中的发育。

英文摘要：

Objective To characterize the structure and distribution of extracellular matrix proteins of testis in 9 yak calves. Methods Histochemistry and transmission electron methods were used to study the microstructure and nltrastructure of yak calves testis, and immnnohistochemical SP technique and Image Pro Plu （IPP） statistics methods were used to identify the distribution of the laminin （LN） , type Ⅳ collagen （ Col Ⅳ ） and heparan sulfate proteo glycans （HSPG）. Results The germinal epithelium of seminiferous tubule was constructed 1-2 layers by Sertoli cells and gonocytcs without appearance of the lumen. The gonocytes were larger and abundant with cytoplasm. Sertoli cells were rich in heterochromatin and the microfilaments constructed by the typical ectoplasmic specialization and actin filament were accumulated in the submembranes regions between the adjacent Sertoli cells. Immunostaining analysis appeared that the extracellular matrix （ECM） proteins LN, ColiV and HSPG were weakly present throughout the basement membranes and peritubular myoid cells in yak calves seminiferous tubule. The relative expression of LN in the gonocytes was significantly lower than Col Ⅳ and HSPG（P 〈 0. 05） , and no expression in Sertoli cells and leydig cells. The strong immunoreactivity for Col Ⅳ and HSPG was seen in the Sertoli ceils. In addition, the distribution of HSPG in the Leydig ceils was higher than Col Ⅳ. Conclusion Taken together, the proliferation of the Sertoli cells is the main causes for the development of the yak calves seminiferous tubule and the Leydig cells are in the transition period which developed from embryonal type to a mature stage ; the distribution of ECM proteins LN, Col IV and HSPG may serve as a meaningful index for the further research of the yak testis development.