Development of a detection system for germ-cell mutagenesis with high sensitivity and multiple genetic endpoints using the Japanese Medaka

使用日本青鳉开发具有高灵敏度和多个遗传终点的生殖细胞突变检测系统

基本信息

批准号：
04558026
负责人：
SHIMA Akihiro
金额：
$ 7.23万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research (B)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1994
项目状态：
已结题

项目摘要

The purpose of the present study is to develop a detection system for germ-cell mutagenesis with high sensitivity and multiple genetic endpoints using the Japanese Medaka Oryzias latipes. About ten years ago, we started developing a non-mammalian test system for detecting environmental germ-cell mutagenesis using the Japanese Medaka. In the middle of the FY 94, we succeeded in establishing a inbred tester strain with three marker loci (b/b ; gu/gu ; lf/lf) , named AA2 inbred strain, by repeating brother-sister mating for more that 20 filial generations. By February 8,1995, we have examined 872,961 embryos that correspond to 2,299,892 loci. Among these were the control with 195,554 embryos corresponding to 501,917 loci. The rate for spontaneous embryonic death was 5.6%, a value almost comparable to the reported one in the mouse (5.8%). The spontaneous total mutation rate and the spontaneous viable mutation rate were, respectively, 3.8x10-5/locus and 4.2x10-6/locus. In the present test system, we succeeded in integrating four genetic endpoints, i.e., dominant lethal mutation, total mutation, viable mutation and external malformation, into one individual, although the quantitation of external malformations was not as successful as the remaining three endpoints. These genetic endpoints showed good dose-response relationships for gamma-rays and fission neutron radiation. Furthermore, the extent of reduction of total mutation rate down to viable mutation rate was about 90%, irrespective of the difference in stages of maturation of male germ cells at the time of exposure to radiations.However, exposure of male germ cells to ENU resulted in different reduction depending on the maturation stages as well as ENU concentration.

本研究的目的是使用日本的Medaka Oryzias latipes开发一种具有高灵敏度和多个遗传终点的种系诱变的检测系统。大约十年前，我们开始开发一种非哺乳动物测试系统，用于使用日本MEDAKA检测环境种系诱变。在94财年的中间，我们成功地建立了一个用三个标记基因座（B/B; gu/gu; lf/lf）的近交测试菌株，称为AA2 Inbred菌株，通过重复兄弟姐妹交配，以增加20个文件。到1995年2月8日，我们检查了872,961个胚胎，对应于2,299,892个位点。其中包括195,554个胚胎对应于501,917个基因座的对照。自发胚胎死亡的速率为5.6％，该值几乎与小鼠报告的值相当（5.8％）。自发的总突变率和自发的可行突变率分别为3.8x10-5/locus和4.2x10-6/lotus。在当前的测试系统中，我们成功地整合了四个遗传终点，即主要的致命突变，总突变，可行的突变和外部畸形，尽管外部畸形的定量并不像剩余的三个终点那样成功。这些遗传终点显示出良好的剂量反应关系，用于伽马射线和裂变中子辐射。此外，无论在暴露于辐射时，男性生殖细胞成熟阶段的阶段差异差异，总突变率降低到可行的突变率约为90％。