Molecular Mechanisms for Maintaining Stem Cell Immaturity

维持干细胞不成熟的分子机制

基本信息

批准号：
12470026
负责人：
NAKANO Toru
金额：
$ 10.5万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12470026/
关键词：
Primordial germ cell Spermatogenesis Teratoma Embryonic germ cell PTEN Germ cell-less Oogenesis 遺伝子破壊細胞分化 PTEN

项目摘要

To reveal the molecular basis of stem cells, we analyzed the function of three genes and found that all of them are essential for germ line stem cell systems.1) We analyzed the function of a tumor suppressor gene PTEN (phosphatase and tensin homologue from chromosome 10). PTEN is a negative regulator of P13kinase by its phosphatase activity catalyzing from PIP3 to PIP2. We produced primordial germ cell (PGC) specific PTEN targeting mouse. The PGC specific PTEN null mice showed teratoma formation in all new born male mice. And the in vitro proliferative activity and embryonic germ cell forming activity was strikingly increased in the null mice.2) We cloned a mouse homologue of Drosophila germ cell less gene which is essential for PGC formation in the fly. To analyze the function of the gene (mouse germ cell less-1, mgcl-1), gene targeting mice were produced. The mice did not show any abnormality in PGC formation. However, the fertility of the targeting mice was significantly reduced. During the study, it was reported that mgcl-1 protein binds to a component of nuclear envelope, LAP2β, which prompted us to examine the nuclear morphology in spermatogenesis. Nuclear morphology of the null spermatocyte was abnormal and subsequent chromatin remodeling was impaired.3) Piwi is a gene essential for germ cell self renewing activity in Drosophila. We cloned one mouse homologue, mili, and analyzed its function by gene targeting. The mili null mice could not produce sperm due to apoptotic cell death at pachytene phase of primary spermatocytes.All of the results facilitates the understanding of molecular mechanisms of stem cells in germ system.

为了揭示干细胞的分子基础，我们分析了三个基因的功能，发现所有基因对于生殖系干细胞系统都是必不可少的。1）我们分析了肿瘤抑制基因PTEN的功能（染色体10中的磷酸酶和Tensin同源物的功能）。 PTEN是p13kinase的负调节剂，其磷酸酶活性从PIP3到PIP2催化。我们产生了原始生殖细胞（PGC）特定的PTEN靶向小鼠。 PGC特异性PTEN无效小鼠在所有新出生的雄性小鼠中呈现畸胎瘤的形成。在无效的小鼠中，体外增殖活性和胚胎生殖细胞的形成活性显着增加。2）我们克隆了果蝇生殖细胞的小鼠同源物，较少的基因，这对于果蝇中的PGC形成至关重要。为了分析基因的功能（小鼠生殖细胞较少1，MGCL-1），产生了靶向小鼠的基因。小鼠在PGC形成中没有任何异常。但是，靶向小鼠的生育能力显着降低。在研究期间，据报道，MGCL-1蛋白与核包膜LAP2β的成分结合，这促使我们检查了精子发生中的核形态。零精子细胞的核形态异常，随后的染色质重塑受损。3）PIWI是果蝇生殖细胞自我更新活性至关重要的基因。我们通过基因靶向克隆了一个小鼠同源物，并分析了其功能。 MILI NULL小鼠由于原代精子细胞的pachytene阶段的凋亡细胞死亡而无法产生精子。所有结果都促进了对生殖系统中干细胞分子机制的理解。