Zhu L J, Zong S D, Phillips D M, Moo-Young A J, Bardin C W
The Population Council, Center for Biomedical Research, New York, New York 10021, USA.
Anat Rec. 1997 Jul;248(3):391-405. doi: 10.1002/(SICI)1097-0185(199707)248:3<391::AID-AR12>3.0.CO;2-K.
Intermediate filaments (IFs) are components of the cytoskeleton. In mammalian Sertoli cell, IFs are formed by vimentin. Previous studies have shown some characteristics of its distribution in Sertoli cells, however, very little is known of its distributional changes during the seminiferous epithelium cycle and during postnatal development.
Immunohistochemical and electron microscopic methods were used to determine the distribution of vimentin-type IFs in rat Sertoli cells during the seminiferous epithelium cycle and postnatal development.
The distribution of IFs in adult rat Sertoli cell showed distinct cyclic changes during the seminiferous epithelium cycle. At stages I-VI, bundles of IFs extend from the perinuclear region to the supranuclear and apical regions of the Sertoli cell. These apical extensions became shorter at stage VII, and at stages VIII-X IFs were observed only in the perinuclear region. Short apical extensions reappeared at stages XI-XII; and at stages XIII-XIV, they extended again into the apical region. During this cycle, IFs were always closely associated with the heads of elongate spermatids. IFs were also shown to be in close apposition to some specialized structures on the cell membrane, such as the ectoplasmic specialization between adjacent Sertoli cells. During postnatal (p.n.) development, IFs were mainly observed at the basal nuclear region on p.n. day 7. The IFs in the supranuclear or apical regions first appeared at p.n. day 14 and gradually increased during the development. The perinuclear IFs network was fully established by p.n. day 28 and the adult distribution pattern of the IFs was established by p.n. day 42.
Vimentin-type IFs in rat Sertoli cells are a delicate endocellular network, which is centered in the perinuclear region and extends to the apical region of the cell. During the seminiferous epithelium cycle, the distribution of IFs changes in a stage-dependent manner and is closely related to the location of the heads of elongate spermatids. During postnatal development, IFs gradually increase in numbers and the main distribution area is transferred from the basal nuclear to the perinuclear and supranuclear regions.
中间丝（IFs）是细胞骨架的组成部分。在哺乳动物的支持细胞中，中间丝由波形蛋白形成。先前的研究已经显示了其在支持细胞中的一些分布特征，然而，对于其在生精上皮周期和出生后发育过程中的分布变化却知之甚少。
采用免疫组织化学和电子显微镜方法来确定波形蛋白型中间丝在大鼠支持细胞生精上皮周期和出生后发育过程中的分布。
成年大鼠支持细胞中中间丝的分布在生精上皮周期中呈现出明显的周期性变化。在I-VI期，中间丝束从核周区域延伸至支持细胞的核上区域和顶端区域。在VII期，这些顶端延伸变短，而在VIII-X期，仅在核周区域观察到中间丝。在XI-XII期，短的顶端延伸再次出现；在XIII-XIV期，它们又延伸至顶端区域。在这个周期中，中间丝始终与长形精子细胞的头部紧密相连。中间丝也显示与细胞膜上的一些特殊结构紧密相邻，例如相邻支持细胞之间的外质特化结构。在出生后发育过程中，在出生后第7天，中间丝主要在核基部区域被观察到。核上或顶端区域的中间丝在出生后第14天首次出现，并在发育过程中逐渐增加。核周中间丝网络在出生后第28天完全建立，中间丝的成年分布模式在出生后第42天建立。
大鼠支持细胞中的波形蛋白型中间丝是一个精细的细胞内网络，以核周区域为中心并延伸至细胞的顶端区域。在生精上皮周期中，中间丝的分布以阶段依赖的方式变化，并且与长形精子细胞头部的位置密切相关。在出生后发育过程中，中间丝数量逐渐增加，主要分布区域从核基部转移至核周和核上区域。
