Identification and characterization of stem cells in prepubertal spermatogenesis in mice
Identification and characterization of stem cells in prepubertal spermatogenesis in mice
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DOI：
10.1016/s0012-1606(03)00111-8
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发表时间：
2003-06-01
影响因子：
2.7
通讯作者：
Suda, T
中科院分区：
文献类型：
--
作者：
Ohbo, K;Yoshida, S;Suda, T
性腺细胞和性腺原细胞在青春期前的干细胞特性仍然很不清楚：性腺细胞和性腺原细胞是一种特殊的细胞类型，还是类似于成人未分化的精原细胞。为了鉴定这些细胞，我们建立了携带增强型绿色荧光蛋白(增强型绿色荧光蛋白)基因的转基因小鼠，在含有最小启动子和近端和远端增强子的Oct418kb基因组片段的控制下；据报道，Oct4在青春期前的未分化精原细胞中表达。转基因小鼠的产生使我们能够从睾丸的体细胞中提纯性腺细胞和成熟原细胞。到目前为止，睾丸细胞的移植研究是用生殖细胞和体细胞的混合物进行的。这是第一个建立如何从总的睾丸细胞中纯化生殖细胞的报告，使得能够评估成熟原细胞亚群的细胞自主再繁殖活动。我们发现，在KIT阴性群体的大小和细胞周期特征方面，精原细胞与成年精原细胞都有明显的不同。在成体环境中，成熟原细胞的GFP(+)Kit(-)组分比GFP(+)Kit(+)组分具有更高的再繁殖活性。有趣的是，与成体KIT阳性精原细胞不同，GFP(+)KIT(+)群体仍然表现出再生活性。我们还发现，激活的白细胞黏附分子alcam在性腺细胞中瞬时表达。支持细胞和肌样细胞也同时表达alcam，提示alcam可能有助于性腺细胞与支持细胞的黏附和性腺细胞向基底膜的迁移。(C)2003年埃尔塞维尔科学公司(美国)。版权所有。
The stem cell properties of gonocytes and prospermatogonia at prepubertal stages are still largely unknown: it is not clear whether gonocytes and prospermatogonia are a special cell type or similar to adult undifferentiated spermatogonia. To characterize these cells, we have established transgenic mice carrying EGFP (enhanced green fluorescence protein) cDNA under control of an Oct4 18-kb genomic fragment containing the minimal promoter and proximal and distal enhancers; Oct4 is reported to be expressed in undifferentiated spermatogonia at prepubertal stages. Generation of transgenic mice enabled us to purify gonocytes and prospermatogonia from the somatic cells of the testis. Transplantation studies of testicular cells so far have been done with a mixture of germ cells and somatic cells. This is the first report that establishes how to purify germ cells from total testicular cells, enabling evaluation of cell-autonomous repopulating activity of a subpopulation of prospermatogonia. We show that prospermatogonia differ markedly from adult spermatogonia in both the size of the KIT-negative population and cell cycle characteristics. The GFP(+)KIT(-) fraction of prospermatogonia has much higher repopulating activity than does the GFP(+)KIT(+) population in the adult environment. Interestingly, the GFP(+)KIT(+) population still exhibits repopulating activity, unlike adult KIT-positive spermatogonia. We also show that ALCAM, activated leukocyte cell adhesion molecule, is expressed transiently in gonocytes. Sertoli cells and myoid cells also express ALCAM at the same stage, suggesting that ALCAM may contribute to gonocyte-Sertoli cell adhesion and migration of gonoyctes toward the basement membrane. (C) 2003 Elsevier Science (USA). All rights reserved.