Germline stem cells
We study mechanisms that regulate the development and function of germline stem cell in zebrafish, with a main focus on female germline stem cells. We study factors that function within the stem cells, as well as those that are required for the development of the somatic gonad, the germ cell niche.
Sex determination and maintenance of the adult sexual phenotype
While zebrafish do not switch sex as adults, our lab has recently discovered that maintenance of the adult female sexual phenotype is an active process that requires continuous input from germ cells, as reduction of germ cell numbers in an adult female results in female-to-male sex reversal. Our current research is focused on determining what signal is produced by the germ cells and how it influences the developmental state of the somatic gonad.
Development of the early somatic gonad
The mechanisms mediating the development of the somatic gonad in vertebrates during the transition from the sexually bipotential state to the sex-specified state are well defined. In contrast, far less is known about the genes acting earlier during formation of the undifferentiated gonad primordium. We recently discovered that a mutation in a zebrafish Fgf ligand, fgf24, results in the rapid loss of germ cells during early larval development, at a time prior to gonad differentiation. Our results suggest that the primary function of fgf24 is to promote the development of early somatic gonad cells, and that the loss of germ cells in fgf24 mutants is secondary to this defect. We are currently investigating the role of fgf24 in regulating the development of the early somatic gonad.