Hamano Koh-Ichi, Sugimoto Ryo, Takahashi Hiroshi, Tsujii Hirotada
Faculty of Agriculture, Shinshu University, Nagano, Japan.
Reprod Med Biol. 2007 Aug 6;6(3):139-149. doi: 10.1111/j.1447-0578.2007.00177.x. eCollection 2007 Sep.
Mammalian spermatogenesis has been studied extensively as a prime theme of male reproductive biology, especially for germ cell production, fertilization and development. Investigation of spermatogenesis has provided us with the opportunity to both study the male germ line stem cells and generate the transgenic animals. Spermatogenesis is conducted in the seminiferous tubules, which end in the rete testis. The organization of spermatogenesis means that the spermatogonia are uniformly distributed around the seminiferous tubules. The pubertal establishment and mature maintenance of spermatogenesis requires precursor cells. In bull testes at 4 weeks postnatal, gonocyte migration occurs and differentiated spermatogonia are recognized after 8 weeks. Within the period of 4-8 weeks of age, spermatogonial stem cell conversion and niche formation must occur. Spermatogonial stem cells are the only cells that can undergo self-renewal in spermatogenesis. Spermatogonial stem cell transplantation can potentially contribute to studies of gene expression during spermatogenesis and provide genetic progress in domestic animals. Bull spermatogonial stem cells have been demonstrated to be capable of colonizing recipient mouse seminiferous tubules. (Reprod Med Biol 2007; : 139-149).
哺乳动物精子发生作为雄性生殖生物学的一个主要主题已得到广泛研究，尤其是在生殖细胞产生、受精和发育方面。精子发生的研究为我们提供了研究雄性生殖系干细胞和培育转基因动物的机会。精子发生在生精小管中进行，生精小管通向睾丸网。精子发生的组织结构意味着精原细胞均匀地分布在生精小管周围。精子发生的青春期建立和成熟维持需要前体细胞。在出生后4周的公牛睾丸中，生殖母细胞发生迁移，8周后可识别出分化的精原细胞。在4至8周龄期间，必须发生精原干细胞转化和微环境形成。精原干细胞是精子发生过程中唯一能够进行自我更新的细胞。精原干细胞移植可能有助于精子发生过程中基因表达的研究，并在家畜中取得遗传进展。已证明公牛精原干细胞能够在受体小鼠的生精小管中定植。（《生殖医学与生物学》2007年；：139 - 149）
