Identification of genes expressed in Drosophila germline

果蝇种系中表达基因的鉴定

• 批准号: 07680793
• 负责人: KOBAYASHI Satoru
• 金额: $ 1.47万
• 依托单位: University of Tsukuba
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07680793/
• 关键词: Drosophila; Pole Cell; Germline; Enhancer-trap; Differential Display; Polar granules; 生殖系列; nanos遺伝子

In many animal groups, factors required for germline formation are localized in a histologically remarkable region in egg cytoplasm, called germ plasm. In Drosophila embryos, germ plasm is localized in the posterior pole region and is inherited in pole cells, the germ-line progenitors in this animal. Transplantation experiments have demonstrated that germ plasm contains factors with sufficient ability to form germ line. Germ plasm also contains a second localized activity that directs the formation of abdomen. Genetic analysis has revealed that a common mechanism directs the localization of the abdomen and germ-line forming factors to the posterior pole. The critical factor for abdomen formation is the product of the nanos (nos) gene.In this study, we show that nos is also esential for germ-line formation in Drosophila. Pole cells lacking nos activity are incapable of becoming functional germ cells because they fail to migrate into the gonads. In such pole cells, enhancer activation which normally initiates within the gonad begins prematurely during pole cell migration. Premature activation of genes in germline precursors may cause these cells to be incapable of following the normal germline developmental program.Furthermore, we have identified an untranslatable RNA,called Pgc, which is localized in germ plasm. Most pole cells in embryos produced by females expressing anti-sense Pgc RNA fail to complete migration and to populate the embryonic gonads, and females which develop from these embryos often have agametic ovaries. Our results support an essential role for Pgc RNA in germ line development.

在许多动物群体中，生殖系形成所需的因子位于卵细胞质中的组织学显著区域，称为生殖质。在果蝇胚胎中，生殖质位于后极区，并在极细胞（这种动物的生殖系祖细胞）中遗传。移植实验证明，种质中含有足够的形成种系的因子。种质还含有第二种局部活性，指导腹部的形成。遗传分析表明，一个共同的机制指导定位的腹部和生殖系形成因素的后极。果蝇腹部形成的关键因素是nanos基因产物，本研究表明nos基因也是果蝇生殖系形成的必需基因。缺乏nos活性的极细胞不能成为有功能的生殖细胞，因为它们不能迁移到性腺中。在这样的极细胞中，增强子激活通常在性腺内启动，在极细胞迁移期间过早开始。生殖系前体细胞中基因的过早激活可能导致这些细胞不能遵循正常的生殖系发育程序。此外，我们已经鉴定出一种位于生殖质中的不可翻译的RNA，称为Pgc。表达反义Pgc RNA的雌性产生的胚胎中的大多数极细胞无法完成迁移并填充胚胎性腺，并且从这些胚胎发育而来的雌性通常具有无配生殖卵巢。我们的研究结果支持Pgc RNA在生殖系发育中的重要作用。

项目成果

A.Nakamura: "Requirement for anoncoding RNA in Drosophila polargranulos for germ cell establishment." Science. 274. 2075-2079 (1996)

A.Nakamura：“果蝇极粒细胞建立生殖细胞所需的非编码 RNA。”