抑制素α基因表达下调对鹅卵泡颗粒细胞凋亡和增殖的影响

抑制素α基因是控制家禽排卵率的一个重要候选基因。为研究抑制素α基因对体外培养的鹅卵泡颗粒细胞增殖凋亡的遗传作用,构建psiRNA-INHα1和psiRNA-INHα2两个抑制素α基因干扰载体,以降低抑制素α基因表达。体外培养鹅F1和闭锁卵泡的颗粒细胞,经抑制素α基因干扰48h后,荧光显微镜检测转染效率,同时用流式细胞术检测抑制素α基因表达水平,以及细胞生长周期、细胞凋亡指数和增殖指数的变化,用放免法测定细胞培养上清中雌激素和孕酮水平。结果表明,抑制素α基因干扰后卵泡颗粒细胞抑制素表达水平比对照组降低30%～40%（P〈0.05）;细胞凋亡指数和增值指数显著高于对照组（P〈0.05）;细胞分泌雌激素水平显著下降（P〈0.05）。由此推断,抑制素α基因对颗粒细胞具有显著的抗凋亡效应。

Effects of Downregulation of Inhibin α Gene Expression on Apoptosis and Proliferation of Goose Granulosa Cells

Inhibin alpha is one of the candidate genes that control the ovulation in poultry. To study the genetic effects of inhibin alpha on apoptosis and proliferation of goose granulosa cells cultured in vitro, two RNA interference (RNAi) expression vectors, psiRNA-INH alpha 1 and psiRNA-INH alpha 2, were constructed to knock down inhibin alpha gene expression. After 48 h of transfection, the efficiency of these two RNAi expression vectors was examined by fluorescence microscopy. Meanwhile, inhibin protein expression levels, apoptosis indexes (AI) and proliferation indexes (PI) of granulosa cells were analyzed by flow cytometry. In addition, the supernatants were collected to assay the concentrations of estrogen (E2) and progesterone (P) by radioimmunoassay. The results showed that the expression level of inhibin alpha in the RNAi group were decreased 30%-40% than those in the control groups (P < 0.05) and the apoptosis indexes and proliferation indexes in the RNAi groups were significantly higher than those in the control groups (P < 0.05). However, the E2 concentrations in the RNAi groups were lower than those in the control groups (P < 0.05). These results indicate that inhibin alpha has antagonistic effect on granulosa cell apoptosis.