Fig. 4. fkh-6::gfp is expressed in the early somatic gonad and the spermatheca. (A-H) Expression of integrated fkh-6(pro)::gfp array. (A,B) DIC and fluorescence micrographs in four-cell gonad of wild-type L1 male, with fkh-6::gfp expression in Z1 and Z4 (arrows). (C,D) Four-cell gonad of wild-type L1 hermaphrodite showing expression in Z1 (arrow). Z4 is out of focal plane. (E,F) Wild-type male gonad in late L1, with expression of fkh-6::gfp reporter in four daughters of Z1 and Z4, which have moved to the anterior (bracket). Reporter expression is no longer detectable in hermaphrodites by this stage (not shown). (G,H) Wild-type L4 hermaphrodite expressing fkh-6::gfp reporter in spermatheca (spth) and weakly in sheath (sh). Fluorescence outside the gonad in these images is intestinal autofluorescence. Reporter expression is not detected in males at this stage (not shown).