Abstract
The classical term germ cell determinant was defined to cover whole function of germ plasm, or morphologically remarkable cytoplasm localized in oocytes and germ cells. Since early 1970 consequential advances in technology, including microsurgery, genetic anatomy and gene manipulation, have allowed cytological and molecular analyses of pole plasm (germ plasm) in Drosophila embryos. A series of recent work has revealed that multiple factors or molecule species in pole plasm participate in a consecutive reactions resulting in germline formation. Two molecule species have been specified as playing roles in germline cell formation. One that participates in sequestering pole plasm from somatic environment is mitochondrial large ribosomal (mtlr) RNA, and the other involved in driving pole cells into the germline pathway is Nanos protein. Studies disclosed the roles of those two molecules are reviewed.
