Molecular biological analysis of ontogenetical expression of inhibin in horse testis.

从形态、组织化学、免疫组织化学、超微结构和分子生物学等方面研究了马精巢的个体发生变化，特别是抑制素α-，βA、βB亚基的表达。马睾丸发育过程中最典型的特征是色素细胞的出现和消失。这些细胞最早出现在3日龄的小马身上，直到1岁时体积逐渐增大。细胞数量在2个月龄时达到最大值，以后逐渐减少，3岁后完全消失。根据组织化学和超微结构特征，这些着色细胞可能是吞噬胎儿型间质细胞的巨噬细胞。免疫组织化学显示，抑制素α-，βA和βB亚基不仅在间质细胞中存在，而且在支持细胞中也存在。但它们的Position…强度为了原位杂交，制备了地高辛标记的完整RNA探针，以检测抑制素α-，βA亚基和βB亚基的胞内信使RNA。在间质细胞和生精上皮基底区检测到抑制素α-，βA和βB亚基的信号。虽然由于这一方法的局限性，无法在生精小管的基底区确定信号的准确定位，但很可能是支持细胞。但不能排除精原细胞。在出生前和出生后阶段，甚至在成年马中，这些结果基本上是相似的。结果表明，抑制素α亚基、抑制素/激活素βA亚基和βB亚基不仅在支持细胞中表达，而且在间质细胞中的表达水平高于支持细胞。此外，本研究表明，间质细胞是马睾丸抑制素和/或激活素的主要来源。抑制素和/或激活素可能通过自分泌和/或旁分泌方式对睾丸功能起调节作用，但具体情况尚不清楚。较少

Ontogenetical changes of horse testis were examined morphologically, histochemically, immunohistochemically, ultractructurally and molecular biologically with special reference to expression of inhibin α-, βA-, βB-subunits.Spermatogenesis initiated in the spring of 2 years old, and spermatogeneic activity appeared to inverase with age up to 9 years old. The most characteristic feature during development of horse testis is the appearance and disappearance of pigmented cells. These cells first appeared in 3-day old colt and gradually increased in volume up to 1 year old. The number of cells reached maximum at 2 months old, graduelly decreased, and completely disappered after 3 years old. According to their histochemical and ultrastructural feature, the pigmented cells might be macrophages phagocytized fetal types of Leydig cells.Immunohistochemically, inhibin α-, βA- and βB-subunits were found not only in Lydig cells but also in Sertoli cells, respectively. But their intensities of posit … More ive stainings were more intense in Lydig cells than in Sertoli cells.For in-situ hybrldization, digoxigenin-labelled comprementary RNA probes were prepared to detect intracellular messenger RNAS of inhibinα-, βA- and βB-subunits. Signals for inhibin α-, βA- and βB-subunits were detected in Leydig cells and the basal region of seminiferous epithelium. Although exact localization of the signals were could not identified in the basal region of the seminiferous tubules due to the limitation of this method, it may well be that Sertoli cells have the highest possibility. However we could not excluded the spermatogonia. During prenatal and postnatal stages and even in adult horses, these seults are fundamentally similar. The present results suggested that inhibin α-subunit and inhibin/activin βA- and βB-subunits were expressed not only in Sertoli cells but also in Lydig cells, and the expression level was higer in Leydig cells than in Sertoli cells. Furthermore this study suggested that Leydig cells are the major source of inhibin and/or activin in horse testis. Inhibin and/or activin may play reguration role of testicular function by autocrine and/or paracrine manner, but they are not known in detail. Less