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，发现它们都是生殖系干细胞系统所必需的。1）我们分析了抑癌基因PTEN（来自染色体的磷酸酶和张力蛋白同源物）的功能10). PTEN 是 P13 激酶的负调节因子，其磷酸酶活性催化 PIP3 到 PIP2。我们生产了原始生殖细胞 (PGC) 特异性 PTEN 靶向小鼠。 PGC特异性PTEN缺失小鼠在所有新生雄性小鼠中均显示出畸胎瘤形成，并且缺失小鼠的体外增殖活性和胚胎生殖细胞形成活性显着增加。2)我们克隆了果蝇生殖细胞缺失基因的小鼠同源物。为了分析果蝇中PGC形成所必需的基因（小鼠生殖细胞less-1，mgcl-1）的功能，产生了基因靶向小鼠，但其生育力并未表现出任何异常。在研究过程中，有报道称 mgcl-1 蛋白与核膜成分 LAP2β 结合，这促使我们检查无效精母细胞的核形态。 3）Piwi是果蝇生殖细胞自我更新活动所必需的基因，我们克隆了一个小鼠同源基因mili，并通过基因打靶分析了其功能。mili缺失小鼠无法产生。初级精母细胞粗线期细胞凋亡导致精子死亡。所有这些结果有助于理解生殖系统中干细胞的分子机制。