HIF-3α/PPAR-γ Regulates Hypoxia Tolerance by Altering Glycolysis and Lipid Synthesis in Blunt Snout Bream (Megalobrama amblycephala).

Hypoxic stress causes cell damage and serious diseases in organisms, especially in aquatic animals. It is important to elucidate the changes in metabolic function caused by hypoxia and the mechanisms underlying these changes. This study focuses on the low oxygen tolerance feature of a new blunt snout bream strain (GBSBF1). Our data show that GBSBF1 has a different lipid and carbohydrate metabolism pattern than wild-type bream, with altering glycolysis and lipid synthesis. In GBSBF1, the expression levels of phd2 and vhl genes are significantly decreased, while the activation of HIF-3α protein is observed to have risen significantly. The results indicate that enhanced HIF-3α can positively regulate gpd1ab and gpam through PPAR-γ, which increases glucose metabolism and reduces lipolysis of GBSBF1. This research is beneficial for creating new aquaculture strains with low oxygen tolerance traits.