Meinhardt A, O'Bryan M K, McFarlane J R, Loveland K L, Mallidis C, Foulds L M, Phillips D J, de Kretser D M
Institute of Reproduction and Development, Monash University, Clayton, Victoria, Australia.
J Reprod Fertil. 1998 Mar;112(2):233-41. doi: 10.1530/jrf.0.1120233.
The cellular localization of the activin-binding protein, follistatin, in the rat testis has been a matter of some controversy with different investigators claiming that Sertoli cells, Leydig cells or germ cells are the primary cell types containing this protein. The localization of mRNA encoding follistatin was re-examined using reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization as well as the distribution of follistatin by immunohistochemistry. The results demonstrate that mRNA encoding follistatin is located in many germ cells including type B spermatogonia, primary spermatocytes with the exception of the late leptotene and early zygotene stages, and spermatids at steps 1 to 11. It is also found in Sertoli cells and endothelial cells but not in Leydig cells. Immunohistochemistry, using two different antisera to follistatin, showed that this protein was localized to spermatogonia, primary spermatocytes at all stages except the zygotene stage, spermatids at all stages and to endothelial cells and Leydig cells in the intratubular regions. The failure to detect mRNA for follistatin in Leydig cells using RT-PCR and in situ hybridization suggests that the immunohistochemical localization in these cells reflects binding of follistatin produced elsewhere. The widespread localization of follistatin, taken together with its capacity to neutralize the actions of activin, may indicate that follistatin modulates a range of testicular actions of activin, many of which remain unknown.
激活素结合蛋白卵泡抑素在大鼠睾丸中的细胞定位一直存在一些争议，不同的研究者声称支持细胞、间质细胞或生殖细胞是含有这种蛋白质的主要细胞类型。利用逆转录-聚合酶链反应（RT-PCR）、原位杂交技术重新检测了编码卵泡抑素的mRNA的定位，并通过免疫组织化学方法检测了卵泡抑素的分布。结果表明，编码卵泡抑素的mRNA存在于许多生殖细胞中，包括B型精原细胞、除细线期晚期和偶线期早期之外的初级精母细胞以及1至11期的精子细胞。在支持细胞和内皮细胞中也发现了该mRNA，但在间质细胞中未发现。使用两种不同的卵泡抑素抗血清进行免疫组织化学检测显示，这种蛋白质定位于精原细胞、除偶线期之外所有阶段的初级精母细胞、所有阶段的精子细胞以及曲细精管内区域的内皮细胞和间质细胞。利用RT-PCR和原位杂交技术未能在间质细胞中检测到卵泡抑素的mRNA，这表明这些细胞中的免疫组织化学定位反映了在其他地方产生的卵泡抑素的结合。卵泡抑素的广泛定位，连同其中和激活素作用的能力，可能表明卵泡抑素调节激活素在睾丸中的一系列作用，其中许多作用仍不清楚。
