In constructs driven by either the -310 to +151 or -56 to +151 region of janA (+1 is the transcription start site for janA), EcollacZ expression is detected in the follicle cell throughout oogenesis. EcollacZ staining in the nurse cell and in the oocyte nucleus is intense from stage S1 to stage S7 of oogenesis, but declines sharply at stage S8. The nurse cell cytoplasm stains faintly. In adult males, staining is detected throughout the testis, but not in male somatic tissue (ejaculatory duct and male accessory gland). However, introductin of four copies of either construct reveals weak staining in male somatic tissue. In third instar larvae, staining is strong in gonads of both sexes, but weak in other tissues.