Surfing the Wave, Cycle, Life History, and Genes/Proteins Expressed by Testicular Germ Cells. Part 1: Background to Spermatogenesis, Spermatogonia, and Spermatocytes
Surfing the Wave, Cycle, Life History, and Genes/Proteins Expressed by Testicular Germ Cells. Part 1: Background to Spermatogenesis, Spermatogonia, and Spermatocytes
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DOI：
10.1002/jemt.20783
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发表时间：
2010-04-01
影响因子：
2.5
通讯作者：
Smith, Charles E.
中科院分区：
文献类型：
--
作者：
Hermo, Louis;Pelletier, R. -Marc;Smith, Charles E.
精子发生是生殖细胞发育的研究，是发生在睾丸曲细精管中的一个漫长、有序、明确的过程。这是一个时间事件，未分化的精原生殖细胞在几周内演变成成熟的精子。精子发生的特征是三个特定的功能阶段增殖，减数分裂和分化，它涉及精原细胞，精母细胞和精子细胞。生殖细胞在发育阶段形成各种细胞联合或阶段，在人类，小鼠和大鼠中鉴定出6，12和14个特定阶段，这些阶段在生精小管的给定区域中随时间演变，形成生精上皮的周期，对于给定物种具有明确的持续时间。在这一部分中，我们讨论了增殖和减数分裂阶段，其中精原细胞经历几次有丝分裂，形成精母细胞，精母细胞经历两次减数分裂，形成单倍体精子细胞。在大鼠中，精原细胞可分为几类，干细胞（A（s））、增殖细胞（A（pn）A（al））和分化细胞（A（1）-A（4），In，B）。它们依赖于由支持细胞、肌样细胞和间质细胞贡献的特定微环境（生态位）进行适当发育。精原细胞具有几种表面标记，由此它们可以彼此识别。在减数分裂期间，精母细胞进行染色体配对，突触，减数分裂后，细胞形成特定的结构实体，如联会复合体和性体。许多基因参与精原细胞的更新和减数分裂过程，已被鉴定并证明是必不可少的。活动microsc研究技术。73：243 - 278，2010（C）2009 Wiley-Liss，Inc
Spermatogenesis, a study of germ cell development, is a long, orderly, and well-defined process occurring in semimferous tubules of the testis. It is a temporal event whereby undifferentiated spermatogonial germ cells evolve into maturing spermatozoa over a period of several weeks. Spermatogenesis is characterized by three specific functional phases proliferation, meiosis, and differentiation, and it involves spermatogonia, spermatocytes, and spermatids Germ cells at steps of development form various cellular associations or stages, with 6, 12, and 14 specific stages being identified in human, mouse, and rat, respectively The stages evolve over time in a given area of the seminiferous tubule forming a cycle of the seminiferous epithelium that has a well-defined duration for a given species. In this part, we discuss the proliferation and meiotic phase whereby spermatogonia undergo several mitotic divisions to form spermatocytes that undergo two meiotic divisions to form haploid spermatids. in the rat, spermatogonia can be subdivided into several classes, stern cells (A(s)), proliferating cells (A(pn) A(al)), and differentiating cells (A(1)-A(4), In, B). They are dependent on a specific microenvironment (niche) contributed by Sertoli, myoid, and Leydig cells for proper development. Spermatogonia possess several surface markers whereby they can be identified from each other During meiosis, spermatocytes undergo chromosomal pairing, synapsis, and genetic exchange as well as transforming into haploid cells following meiosis The meiotic cells form specific structural entities such as the synaptonemal complex and sex body Many genes involved in spermatogonial renewal and the meiotic process have been identified and shown to be essential for this event. Microsc Res. Tech. 73:243-278, 2010 (C) 2009 Wiley-Liss, Inc