Animals are made of two major cell types, somatic cells that are responsible for the development and survival of the organism (e.g. muscle cells, cells in the nervous system etc.) and germ cells that are responsible for the generation of a new organism in the next generation by forming sperm and eggs. Scientists at the MPI in Göttingen are studying the development of germ cells in zebrafish, a vertebrate model organism that offers numerous advantages for such studies. Importantly, zebrafish embryos develop outside the body of the mother and are translucent allowing us to easily observe the germ cells within the live animal. Moreover, in studying the development of the cells we can use a large number of genetic techniques such as reducing the level of specific proteins, expression of different genes in different positions in the embryo etc. The research focus of our group is the understanding of the molecular basis for early germ cell development and behavior as well as studying the interaction between somatic and germ cells. To this end we analyze the mechanisms that are responsible for the segregation of the somatic and germ cell populations and the mechanisms responsible for the migration of the cells towards the gonad, the organ in which they generate sperm and eggs. Using mutations affecting the development of somatic cells we can determine whether the somatic cells provide the germ cells with signals important for their development and conversely, we analyze the development of somatic cells in which germ cell development is blocked.