HEDGEHOG IS REQUIRED FOR THE PROLIFERATION AND SPECIFICATION OF OVARIAN SOMATIC-CELLS PRIOR TO EGG CHAMBER FORMATION IN DROSOPHILA

The hedgehog (hh) gene plays a role in regulating cell proliferation a nd specifying cell identity in diverse systems. We show that hh is exp ressed at the extreme apical end of Drosophila ovarioles in terminal f ilament cells and a newly identified group of associated somatic cells . Reducing or ectopically expressing hh affects somatic cells in regio n 2 of the germarium, 2-5 cells away from the cells in which Hh protei n is detected. hh activity stimulates the proliferation of pre-follicl e somatic cells, and promotes the specification of polar follicle cell s. hit signalling during egg chamber assembly appears to be closely re lated to, or part of pathways involving the neurogenic genes.