Transcriptionally controlled transcription factor. Important for the differentiation of various specialized cell types that arise from both endoderm and mesoderm. May have a role in early gut formation. Plays an essential role in lipid catabolism, regulating lipid mobilization and beta-oxidation in response to nutrient deprivation. Homodimer. In third instar larvae, expressed at high levels in midgut and attached gastric caeca, fat body, Malpighian tubules and oenocytes, and at lower levels in proventriculus, salivary glands, epidermis, brain and ring gland. Not detected in imaginal disks and the median neurosecretory cells that produce insulin-like peptides (at protein level). In developing embryos, expressed in mid-gut, fat bodies and the distal region of Malpighian tubules. Under normal culture conditions, the flies progress through development until they die during or shortly after adult eclosion. Under low density culture conditions, many flies survive and develop into morphologically normal adults. The mutant flies are, however, very sensitive to starvation, displaying inability to efficiently mobilize stored lipid in the midgut and fat body, increased levels of long-chain fatty acids and triglycerides, and premature death. Belongs to the nuclear hormone receptor family. NR2 subfamily. Truncated N-terminus. Extended N-terminus. Extended N-terminus.