Testicular morphogenesis -: Comparison of in vivo and in vitro models to study male gonadal development
Testicular morphogenesis -: Comparison of in vivo and in vitro models to study male gonadal development
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DOI：
10.1196/annals.1411.015
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发表时间：
2007-01-01
期刊：
影响因子：
--
通讯作者：
Schlatt, Stefan
中科院分区：
文献类型：
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作者：
Gassei, Kathrin;Schlatt, Stefan
功能性精巢的器官发生是每个物种雄性生殖力和延续的基础。在哺乳动物中，睾丸发育取决于胚胎和青春期发育期间的两个关键事件。首先，初级性别决定是由Y染色体上的Sry基因表达启动的，并指导原始性腺向睾丸发育而不是卵巢分化。雄性途径包括性腺原基中体细胞的高度调节的细胞分化，以及中肾细胞和原始生殖细胞的迁移，最终导致睾丸索的形成。这些索是雄性性腺分化的最早可见标志。第二，在青春期，未成熟的支持细胞停止增殖并分化成有丝分裂后的成人表型。支持细胞的成熟是启动和维持精子发生的关键。支持细胞在睾丸发育和精子发生过程中的两种独立功能的调节机制还知之甚少。本文对胚胎性腺发育和睾丸成熟的不同模型进行了比较。在体内模型，器官和细胞培养系统进行了讨论，就其适用性研究睾丸器官发生。然后，提出了一种新的组织工程方法，模仿男性胚胎性腺发育，并提供了新的方法来研究早期睾丸分化，以及支持细胞成熟和精原干细胞龛的形成。
The organogenesis of a functional testis is the basis for male fertility and perpetuation of each species. In mammals, testicular development is dependent on two crucial events during embryonic and pubertal development. First, primary sex determination is initiated by expression of the Sry gene on the Y chromosome and directs the primordial gonad toward testicular development rather than ovarian differentiation. The male pathway comprises highly regulated cell differentiation of somatic cells within the gonadal primordium, as well as migration of mesonephric cells and primordial germ cells, ultimately leading to the formation of testis cords. These cords present the earliest visible sign of male gonadal differentiation. Second, during puberty immature Sertoli cells cease to proliferate and differentiate into their postmitotic, adult phenotype. The maturation of the Sertoli cells is pivotal for initiation and maintenance of spermatogenesis. The regulation of the two separate functions of Sertoli cells-during testis development and in spermatogenesis-are poorly understood. In this review, different models that have been used to study embryonic gonadal development and testicular maturation are compared. In vivo models, organ, and cell culture systems are discussed as regards their applicability to study testicular organogenesis. Then, a new tissue engineering approach is presented that mimics male embryonic gonadogenesis and that offers novel ways to study early testicular differentiation, as well as Sertoli cell maturation and spermatogonial stem-cell niche formation.