线粒体tRNA-Lys(T7719G)基因变异对绵羊卵巢颗粒细胞生理功能的影响

Effects of mitochondrial tRNA-Lys(T7719G)gene variations on the physiological function of granulosa cells in sheep

颗粒细胞是卵泡的重要组成部分,可分泌多种卵泡发育所需的因子调控卵母细胞的生长、分化、成熟和闭锁。研究表明线粒体tRNA变异改变线粒体融合、分裂和自噬等生理功能。本试验对绵羊卵巢组织进行PCR扩增产物测序确定tRNA-Lys基因型,使用流式细胞仪测定细胞凋亡情况,采用Western blot技术检测颗粒细胞内线粒体融合相关蛋白Mfn1、Mfn2及分裂相关蛋白Drp1、MFF的蛋白表达水平。结果表明,线粒体tRNA-Lys基因7 719位点存在T→G变异,所以存在G、T两种基因型;G基因型颗粒细胞凋亡率显著降低(P<0.05),G分裂相关蛋白MFF含量显著升高(P<0.05)。综上,线粒体tRNA-Lys(T7719G)基因变异对绵羊颗粒细胞凋亡有明显抑制作用,显著提高分裂相关蛋白MFF表达量,促进细胞分裂。

Granulosa cells are important components of the follicle,and they secrete a variety of factors required for follicular development to regulate oocyte growth,differentiation,maturation and atresia.Studies have shown that mitochondrial tRNA variants alter physiological functions such as mitochondrial fusion division and autophagy.In this study,genotypes were determined by sequencing PCR amplification products from ovarian tissues of sheep,and apoptosis was measured by flow cytometry.The results showed that there were two genotypes of mitochondrial tRNA-Lys gene,G and T.The apoptosis rate of the granulosa cells of genotype G was significantly lower(P<005).The con-tent of division-related protein MFF was significantly higher(P<005),and mitochondrial fission was enhanced in genotype G samples.Taken together,mitochondrial tRNA-Lys(T7719G)significantly reduced the rate of apoptosis,increased the value of the division-related protein MFF,and promoted and increased cell division.