Cloning and sequencing of a cDNA for poly(A)+RNA responsible for pole cell formation in Drosophila embryos.

本项目的最终目标是确定极性质作为种质功能的分子基础。在果蝇中，极性质可以自主启动极细胞的形成，并使极细胞发育为生殖细胞。我们已经在果蝇中证明了母系转录的poly(a)^+RNA负责极细胞的形成，并提出这种RNA是胚质的一个组成部分。本项目克隆了该poly(A)^+RNA的cDNA，并测定了其核苷酸序列。用计算机程序对DNA数据库进行检索，结果表明该cDNA序列与线粒体大核糖体DNA严格同源，但与核DNA不同源。

Final goal of the present project is to elecidate the molecular basis for the function of polar plasm as the germ plasm. In Drosophila, polar plasm is known to autonomously initiate pole cell formation and commit the pole cells to develop to germ cells. We already showed in Drosophila that a maternally transcribed poly(A)^+RNA was responsible for pole cell formation, adn proposed that this RNA was a component of germ plasm. In this project we cloned cDNA of this poly(A)^+RNA, and determined the nucleotide sequence of the cDNA. A search in a DNA data base by a computer program showed that this cDNA sequence is strictly homologous with mitochondrial large ribosomal DNA but not with nuclear DNA.