Molecular characterization and expression of Megalobrama amblycephala (Wuchang bream) lysine monomethylase set7 and its potential role in hypoxia adaptation

Previously, we reported that the mammalian lysine monomethylase SET7 impairs the transcriptional activity of hypoxia-inducible factor (HIF), and set7-deficient zebrafish exhibit enhanced tolerance to hypoxia stress. Megalobrama amblycephala, an extensively farmed endemic species in China, is highly sensitive to hypoxia stress, which has posed a serious threat to its intensive and large-scale culture. Therefore, it is meaningful to identify key candidate genes related to the hypoxia tolerance trait in Megalobrama amblycephala. In this study, we found that set7 is highly conserved across species. The luciferase reporter assay showed that Megalobrama amblycephala set7 inhibits the transcriptional activity of hif-1αa/b and hif-2αa/b. Furthermore, using the fluorescent glucose analog 2-NBDG, we observed that overexpression of Megalobrama amblycephala set7 inhibited glucose uptake in EPC cells under hypoxic conditions. Our findings may provide clues to understand the function of Megalobrama amblycephala set7 in the hypoxia signaling pathway, and provide a potential target for genetic breeding of hypoxia tolerant species.