Changes of the cytoskeletal structures in the peritubular myoid cells in the testis and their effects on spermatogenesis

1.肌样细胞肌动蛋白细丝排列的生后发育15日龄大鼠肌样细胞内仅见环状束肌动蛋白细丝，30日龄时出现纵束状肌动蛋白细丝。40d时，生精上皮内出现细长的精子细胞，此时，在成体睾丸内可见放线丝的晶格排列。这些结果表明，在精子发生完成之前，肌样细胞可能在形态上成熟。2.隐睾症对肌样细胞肌动蛋白细丝的影响实验性隐睾症的诱导，导致腹部高温导致精子发生中断。腹膜缩窄后7天，大鼠肌样细胞肌动蛋白细丝排列明显破坏。这一结果提示肌样细胞中肌动蛋白细丝的排列对于正常的精子发生很重要。3.肌样细胞中α-肌动蛋白的分布用激光共聚焦显微镜和免疫电子显微镜对肌样细胞中的一种肌动蛋白α-肌动蛋白进行免疫定位。该蛋白呈点状分布在肌样细胞的肌动蛋白细丝束中，并存在于肌样细胞的致密小体中。这些结果与其他报道一致，表明α-肌动蛋白存在于鸡胆和胃肌层的平滑肌细胞致密体中。4.细胞骨架与Fyn酪氨酸激酶在小鼠睾丸中的关系为了进一步研究细胞骨架蛋白在睾丸中的功能，研究了Fyn酪氨酸激酶的分布。Fyn是src家族的成员，src与细胞骨架蛋白相互作用，参与细胞的生长和分化。免疫组织化学结果显示，Fyn蛋白定位于小鼠睾丸支持细胞中，并与肌动蛋白细丝共存。

1.Postnatal development of the arrangement of actin filaments in myoid cellsOnly circular bundles of actin filaments were seen in the rat myoid cells at 15 days of age, and longitudinal bundles appeared at 30 days. The lattice arrangement of the actinfilaments, whicih was seen in the adult testis, was completed at 40 days when elongated spermatids occurred in the seminiferous epithelium. These data suggest that the myoid cells may mature morphologically before the completion of spermatogenesis.2.Effect of cryptorchidism on actin filaments in myoid cellsThe induction of experimental cryptorchidism results in the disruption of spermatogenesis by high abdominal temperature. Seven days after abdominal confinement, the arrangement of actin filaments in the rat myoid cells showed a remarkable disruption. This result suggests that the arrangement of actin filaments in the myoid cell is important for normal spermatogenesis.3.Distribution of alpha-actinin in myoid cellsOne of the actin-binding proteins, alpha-actinin, was immunolocalized in the rat myoid cells by confocal laser microscopy and immuno-electron microscopy. This protein was distributed as dots in the actin filament bundles of the myoid cells, and appeared to exist in dense bodies of the myoid cells. These results correspond to other reports showing the existence of the alpha-actinin in dense bodies of smooth muscle cells in the chicken gizzard and in stomach muscle layrs.4.Relationship between cytoskeleton and Fyn tyrosine kinase in the mouse testisTo study further on the function of cytoskeletal proteins in the testis, distribution of Fyn tyrosine kinase was investigated. Fyn is a member of the Src family, and Src plays a role in cell growth and differentiation, interacting with cytoskeletal proteins. Immunohistochemical results showed that Fyn protein was localized in Sertoli cells in the mouse testis, and that was colocalized with actin filaments.