Transcriptional activator that binds to the consensus sequence 5'-[AT]GATA[AG]-3' (PubMed:26700680). Required for gut-specific differentiation, specifically acting with the GATA region-binding transcription factor elt-2 to control normal gene expression and promote normal formation of the intestine (PubMed:20807527, PubMed:24257624). May have a protective role in response to infection by Gram-negative bacteria such as P.aeruginosa (PubMed:21168435). Expressed highly during embryogenesis. Expressed in the endoderm in cells of the gut lineage beginning at the 2E cell stage (endodermal cell stage) of embryogenesis through to adulthood. Induced by P.aeruginosa infection. No obvious phenotype (PubMed:20807527). RNAi-mediated knockdown results in no obvious phenotype (PubMed:18448117). Following infection with P.aeruginosa, RNAi-mediated knockdown results in reduced survival and slight intestinal distension (PubMed:21168435). Double mutation with elt-2 results in arrest at the L1 stage of larval development, reduced expression of gut-specific genes and a severe disruption to normal gut differentiation with the absence of birefringent and rhabditin granules, which are characteristic of normal gut differentiation, largely at the regions of the cell that interface with the pharyngeal and rectal valves (PubMed:20807527). These mutants also have essentially no gut lumen, with only infrequent patches of lumen and brush border in few animals, and reduced gut epithelialization as indicated by reduced expression of epithelial markers erm-1b, itx-1 and ajm-1 (PubMed:20807527).