Probable transcription factor which may have a role in detoxifying dietary metabolites arising from bacterial tryptophan metabolism (PubMed:23499532). Required for fertility and involved in proper postembryonic germline development, especially germline stem cell (GSC) proliferation (PubMed:23499532). Required for activation of the methionine/S-adenosylmethionine (Met/SAM) cycle in response to low levels of SAM (PubMed:33016879). Expressed in germ and intestinal cells and at low levels in the hypodermis. First expressed in the embryo and subsequently in larvae and adults. No obvious somatic morphological defects in adults (PubMed:23499532). However, shows diet-sensitive sterility arising from germ-cell proliferation defects (PubMed:23499532). Sterile when fed the standard bacterial strain, E.coli B (OP50) as food source, and fertile when maintained on E.coli K-12 strains or bacterial soil isolates (PubMed:23499532). Dietary supplementation of L-tryptophan, but not the D isomer, to E.coli B strains suppresses sterility; this effect requires live bacteria (PubMed:23499532). Sterility when fed E.coli B strain OP50 can be rescued by dietary supplementation of either vitamin B12, methionine or choline (PubMed:33016879). RNAi-mediated knockdown targeted to the intestine, but not the germline, restored almost normal fertility on an E.coli OP50 diet (PubMed:23499532). RNAi-mediated knockdown on a rrf-1 mutant background, in which knockdown occurs mainly in the germline but occurs only weakly in somatic tissues, allowed recovery of a majority (64%) of fertile animals (PubMed:23499532). RNAi-mediated knockdown on an nhr-10 mutant background suppresses expression of acdh-1 (PubMed:33016879). Belongs to the nuclear hormone receptor family. It has been reported that mutant phenotypes can be rescued by tryptophan dietary supplementation, but not by methionine (PubMed:23499532). However, a later report describes successful phenotype rescue by methionine supplementation; this may be due to methodological differences (PubMed:33016879).