BBB seminar: Lisbeth C. Olsen
Metazoans and germ line development
Lisbeth C. Olsen
Department of Molecular Biology, University of Bergen, and Sars International Centre for Marine Molecular Biology, Bergen
Since August Weismann proposed his germ plasm theory more then 100 years ago, the dichotomy between germ line and soma has been a fundamental issue in biology. It addresses how the fundamental distinctions between germ cells and somatic cells are initiated and maintained throughout development. The germ cell lineage is unique in its ability to generate totipotent cells, a process that occurs through the fusion of mature gametes, egg and sperm. In most animals, germ-soma segregation occurs early during development. After germ-soma segregation is completed, the primordial germ cells migrate towards the location where the gonadal primordia form. Here the germ cells differentiate according to their somatic environment. Mechanisms by which germ cells are specified and maintained in metazoans, and how these issues relate to our model organism - the zebrafish - will be discussed. I will highlight our work on the DEAD-box RNA helicase VASA, a conserved marker for the developing germ line in metazoans.