Background: Hypoxia-inducible factor 1 (HIF-1) is a key transcription factor in the detection of low oxygen levels, inducing expression of genes involved in mediating the response to hypoxia to maintain cellular oxygen homeostasis. Caenorhabditis elegans is a soil nematode that has evolved specialized chemosensory neurons that detect changes in oxygen levels and guide its behaviour and responses to food. The role of the hif-1 gene in modifying chemosensory behaviour in response to chemical hypoxia however remains unclear. Furthermore, the role of epigenetic modifiers in mediating this behavioural response to hypoxia is unclear. Aims: Our study addresses two questions (a) Do hypoxia-mimetics modify worm behaviour and (b) Are these behaviours modulated by HIF-dependent expression of epigenetic regulators? Material and methods: This study used established behavioural paradigms in hif-1 mutant strains of C. elegans, to study responses to chemical hypoxia. Results: We show that exposure to the hypoxia-mimetic, sodium sulphite, changes the gustatory responses, chemotaxis, gustatory plasticity and associative conditioning behaviour. Longer-term exposure to hypoxia changes the behavioural response of wild type C. elegans, mediated by the HIF pathway. Epigenetic modifiers, lithium chloride and valproic acid, further modulate these behavioural responses.
Keywords: Hypoxia; behaviour; epigenetic.