Required for the terminal differentiation of seam cells, and the differentiation of distal tip cells important for normal somatic gonad and germ cell development. Plays a role in the Wnt signaling pathway, regulating the expression of beta-catenin homologs wrm-1, bar-1 and sys-1, and the localization of wrm-1 and the wnt signaling pathway component pop-1 during asymmetric cell division of seam cells and the Z-cell lineage of the somatic gonad, respectively. May have a pro-apoptotic role, possibly linked to the negative regulation of expression of anti-apoptotic factor ced-9. Ubiquitous. Expressed in the hypodermis from embryogenesis to adulthood. Animals are sterile producing no oocytes, display a protruding vulva phenotype past the young adult stage of development, and have disrupted or no alae formation. Fewer seam cells in larval stages post the L1 larval stage of development and impaired seam cell differentiation with large and irregularly shaped nuclei in seam cell-derived hyp7 cells. Defective gonadal growth and proliferation whereby gonads are thin and shortened probably due to decreased mitosis, and abnormal germ cell nuclei which are irregularly shaped and enlargened. Mis-localization of the beta-catenin homolog wrm-1 in the daughter cells of seam cells following cell division with expression equal to or stronger in the anterior daughter cells as opposed to the posterior daughter cells in 50% of mutants. Aberrant asymmetric localization of the wnt signaling component pop-1 in the nuclei of Z1 and Z4 somatic gonadal precursor cells. Increased expression of anti-apoptotic factor ced-9. RNAi-mediated knockdown results in egg-laying defective and burst vulva phenotypes. Belongs to the BCL7 family.