Molecular basis of primordial germ cell formation from multipotent stem cells in the polychaete Platynereis dumerilii, an ancestral lophotrochozoan.

• Applicant: Dr. Nicole Rebscher
• Subject Area: Evolutionary Cell and Developmental Biology (Zoology) ; Evolution, Anthropology
• Term: from 2009 to 2013
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 161759413

Basal metazoans such as cnidarians and platyhelminthes exhibit stem cells, which give rise to both somatic descendants and primordial germ cells. Recently we could show that similar multipotent stem cells exist in the growth zone of the polychaete Platynereis du-merilii. In order to elucidate the molecular mechanism underlying the formation of germ cells from stem cells in this lophotrochozoan, this project follows three approaches: (1) The function of the germ cell-related genes vasa and nanos will be elucidated by RNAi. (2) Injections of capped mRNA from EGFP:3’UTR constructs into fertilized eggs will pro-vide information on the role of the 3’untranslated region of vasa and nanos in the stabiliza-tion of the corresponding transcripts. Furthermore, this approach will not only allow visual-izing and manipulating of the primordial germ cells of Platynereis for the first time in vivo, but also unraveling regulatory elements and putative micro-RNA binding sites in the 3’UTRs. (3) inhibitor experiments will identify the signaling cascades (FGFR, Notch, Wnt, MAPK) involved in PGC specification. Besides unraveling the molecular mechanism of germ cell formation in Platynereis, this project will contribute to a better understanding of the evolutionary relationship between germ cells and stem cells in Metazoa.

• DFG Programme: Research Grants