Involved in the response to variation in environmental oxygen levels by inhibiting hif-1-mediated gene transcription in a vhl-1-independent manner (PubMed:16980385). Plays a role in susceptibility to killing mediated by P.aeruginosa and by pore-forming toxins produced by B.thuringiensis (PubMed:20011506, PubMed:20865124). Probably by preventing hif-1 transcriptional activity, regulates behavioral responses, such as locomotion speed following acute reoxygenation (PubMed:22405203). Plays a role in normal egg-laying probably by regulating spermatogenesis and in body morphogenesis (PubMed:16980385). Expressed in intestine, some sensory neurons in the head, body wall muscles and socket cells. In L4 stage, expressed in vulva, ventral nerve cord, tail and at higher levels in hypodermis. Induced by hypoxia. Impaired acute acceleration of locomotion speed upon rapid increase in oxygen levels (from 0% to 5-20% oxygen). In double mutants for both rhy-1 and hif-1, normal increase in locomotion speed is restored.