STAGE-SPECIFIC AND CELL-SPECIFIC GENE-EXPRESSION AND HORMONE REGULATION OF THE SEMINIFEROUS EPITHELIUM
STAGE-SPECIFIC AND CELL-SPECIFIC GENE-EXPRESSION AND HORMONE REGULATION OF THE SEMINIFEROUS EPITHELIUM
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DOI：
10.1002/jemt.1060190207
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发表时间：
1991-10-01
期刊：
影响因子：
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通讯作者：
PARVINEN, M
中科院分区：
文献类型：
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作者：
TOPPARI, J;KANGASNIEMI, M;PARVINEN, M
精子发生的调节似乎涉及睾丸中复杂的细胞相互作用。对这些蜂窝通信事件知之甚少。随着分子生物学技术和细胞或细胞群分离方法的发展，对生精细胞和支持细胞的功能分析成为可能，从而对精子发生的旁分泌调节机制有了新的认识。在这篇综述中，我们将描述如何曲细精管段与不同的细胞协会可以快速分离，以及如何通过高能X射线照射的细胞组成可以修改。现将这些技术的最新研究结果作一简要总结。在生精细胞发育的特定阶段，可在活体条件下用透照技术分离出生精细胞，用于形态学和生化学研究。为了准确鉴定生精上皮细胞周期的各个阶段，使用了活细胞挤压物的相差显微镜。Leblond和Clermont（Am.纽约大学科学，55：548-573，1952）可用于准确识别周期的大多数阶段。然而，在一些研究中很重要的I期和II期以及VII期的亚期很难区分。因此，除了早期精子细胞的形态外，精子发生第16步鞭毛的发育和细胞质叶形态的变化（残留尸体）作为快速识别和隔离的标准用北方印迹分析核蛋白和热休克蛋白70相关蛋白基因的表达，狭缝印迹和原位杂交技术在精确分期的曲细精管中。在精子细胞中，类染色体体（cb）被认为在储存长寿命mRNA方面具有特殊的功能。它是一个活跃的细胞质细胞器，在顶体系统形成过程中与高尔基复合体相互作用。类染色体显然也依赖于细胞质微管，因为它的运动受到抑制，它的结构变得异常，在长春新碱的存在下，微管蛋白聚合的抑制剂。卵泡刺激素（FSH）是一个重要的调节支持细胞功能。由于基础和FSH依赖性的环腺苷酸（cAMP）的生产曲细精管表现出显着的阶段依赖性，支持细胞显然是生精细胞的影响。因此，支持细胞功能根据生精上皮周期的阶段而周期性变化，以提供精子发生的最佳微环境。支持细胞和生精细胞之间的相互作用的进一步证据，通过调查阶段依赖性反应的曲细精管FSH局部X射线照射后，当定义的生殖细胞在生精上皮中的数量低。特异性生精细胞的缺乏改变了FSH刺激的cAMP产生。对精子发生的细胞和分子机制的研究对于我们理解精子发生的激素调节是非常重要的。
The regulation of spermatogenesis seems to involve complex cell interactions in the testis. Little is known about these cellular communication events. Advances in molecular technology and cell or cell group separation methods have made it possible to analyze function of defined spermatogenic and Sertoli cells, thereby giving some insights into the paracrine regulation of spermatogenesis. In this review we will describe how seminiferous tubule segments with distinct cell associations can be rapidly isolated and how the cell composition can be modified by high-energy X-irradiation. Results of the recent studies performed using these techniques will be briefly summarized.Spermatogenic cells at defined stages of their development can be isolated in living condition for morphological and biochemical studies by the transillumination technique. For accurate identification of the stages of the seminiferous epithelial cycle, phase contrast microscopy of live cell squashes has been used. The criteria described by Leblond and Clermont (Am. NY Acad. Sci., 55:548-573, 1952) can be used for accurate recognition of most of the stages of the cycle. However, stages I and II and substages of VII that are important in several studies are difficult to distinguish. Therefore, in addition to the morphology of early spermatids, development of the flagella at step 16 of spermiogenesis and the changing morphology of the cytoplasmic lobes (residual bodies) at stage VII of the cycle were used as criteria for rapid identification and isolation (preparative) of the seminiferous tubule segments.Expression of nucleoprotein and heat shock protein 70-related protein genes was analyzed with Northern blot, slot blot, and in situ hybridization techniques in accurately staged seminiferous tubules. Accurate stage-dependent timing of the onset of transcription, followed by storage and disappearance of the messages was demonstrated.The chromatoid body (cb) has been proposed to have a specific function in storage of the long-lived mRNAs in the spermatids. It is an actively moving cytoplasmic organelle that interacts with Golgi complex during formation of the acrosomic system. The chromatoid body is apparently also dependent on cytoplasmic microtubules, since its movements are inhibited and its structure becomes abnormal in the presence of vincristin, an inhibitor of tubulin polymerization.Follicle-stimulating hormone (FSH) is an important regulator of Sertoli cell function. Since both basal and FSH-dependent cyclic AMP (cAMP) production by seminiferous tubules showed marked stage dependency, Sertoli cells are apparently influenced by spermatogenic cells. Thus, Sertoli cell function varies cyclically depending on the stage of the seminiferous epithelial cycle to provide an optimal microenvironment for spermatogenesis. Further evidence of the interactions between Sertoli cells and spermatogenic cells was obtained by investigating stage-dependent responses of the seminiferous tubules to FSH after local x-irradiation, when defined germ cells were low in number in the seminiferous epithelium. The absence of specific spermatogenic cells changed FSH-stimulated cAMP production. Studies of the underlying cellular and molecular mechanisms are important for our understanding of the hormonal regulation of spermatogenesis.