Ogawa Takehiko, Ohmura Masako, Ohbo Kazuyuki
Department of Urology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
Int J Hematol. 2005 Dec;82(5):381-8. doi: 10.1532/IJH97.05088.
The theory of the "stem cell niche" was originally proposed for the hematopoietic system, and the existence of the niche as an actual entity was proved in the Drosophila germ cell system. Historically, mammalian spermatogenesis has been studied extensively as a prime example of a stem cell system, and studies have established a stem-progenitor hierarchical order of spermatogonia. In the niche on the basal lamina of seminiferous tubules, spermatogonial stem cells (SSCs) are secluded from the outside world and divide constantly to self-renew and differentiate. During the last 10 years, the development and exploitation of the germ cell transplantation method has expanded our understanding of the nature of SSCs and their niches. The ability to maintain and expand SSCs in vitro, which recently became possible, has further reinforced this research area as a mecca of stem cell biology. Nonetheless, the mammalian germ stem cell and its niche remain to be defined more strictly and precisely. We are still on a journey in search of the real stem cell and its true niche.
“干细胞微环境”理论最初是针对造血系统提出的，而该微环境作为一个实际存在的实体在果蝇生殖细胞系统中得到了证实。从历史上看，哺乳动物精子发生作为干细胞系统的一个典型例子已被广泛研究，并且研究已经确立了精原细胞的干细胞 - 祖细胞层级顺序。在生精小管基膜上的微环境中，精原干细胞（SSCs）与外界隔绝，不断分裂以实现自我更新和分化。在过去的10年里，生殖细胞移植方法的发展和应用拓展了我们对SSCs及其微环境本质的理解。最近实现的在体外维持和扩增SSCs的能力，进一步巩固了这个研究领域作为干细胞生物学圣地的地位。尽管如此，哺乳动物生殖干细胞及其微环境仍有待更严格和精确地定义。我们仍在寻找真正的干细胞及其真实微环境的征程中。
