Singh B, Armstrong D T
Department of Obstetrics and Gynaecology, University of Western Ontario, London, Canada.
Biol Reprod. 1995 Dec;53(6):1429-35. doi: 10.1095/biolreprod53.6.1429.
The present study was undertaken to determine transforming growth factor alpha (TGF alpha) gene expression in various components of medium-sized porcine ovarian follicles by reverse transcription-polymerase chain reaction, and to localize the peptide during folliculogenesis by immunocytochemistry. A strong signal for TGF alpha transcript was detected in cumulus and granulosa cells, whereas the signal in theca cells was very weak but detectable. No TGF alpha mRNA was detected in the oocyte. Immunolocalization studies revealed intense TGF alpha staining in cumulus and granulosa cells of all stages of follicular development. TGF alpha immunostaining was also observed in the oocytes of primordial and primary follicles. In antral follicles, immunostaining was observed only in cumulus and mural granulosa cells, whereas theca cells and oocytes exhibited very little or no detectable staining. TGF alpha immunostaining was absent in follicles undergoing atresia. No TGF alpha immunostaining was observed when the antibody was omitted from the procedure, and the staining was substantially reduced when the primary antibody was preabsorbed with the same mass of TGF alpha peptide, suggesting the specificity of the staining procedure. These results suggest a local follicular production of TGF alpha in the porcine ovary and thus a role for TGF alpha of follicular origin in the regulation of follicular development in an autocrine/paracrine fashion.
本研究旨在通过逆转录-聚合酶链反应确定转化生长因子α（TGFα）基因在中等大小猪卵泡各组分中的表达，并通过免疫细胞化学在卵泡发生过程中定位该肽。在卵丘细胞和颗粒细胞中检测到TGFα转录本的强信号，而在膜细胞中的信号非常弱但可检测到。在卵母细胞中未检测到TGFα mRNA。免疫定位研究显示，在卵泡发育各阶段的卵丘细胞和颗粒细胞中，TGFα染色强烈。在原始卵泡和初级卵泡的卵母细胞中也观察到TGFα免疫染色。在有腔卵泡中，仅在卵丘细胞和壁颗粒细胞中观察到免疫染色，而膜细胞和卵母细胞的染色很少或未检测到。闭锁卵泡中不存在TGFα免疫染色。当程序中省略抗体时未观察到TGFα免疫染色，并且当一抗用相同质量的TGFα肽预吸收时，染色显著减少，表明染色程序的特异性。这些结果表明猪卵巢中卵泡局部产生TGFα，因此卵泡来源的TGFα在以自分泌/旁分泌方式调节卵泡发育中起作用。
