Comparative analysis of liver transcriptomes associated with hypoxia tolerance in the gynogenetic blunt snout bream

The blunt snout bream (Megalobrama amblycephala, BSB) is important economic fish, but it is sensitive to hypoxia. To overcome this shortcoming, we previously obtained gynogenetic blunt snout bream (GBSB) with the enhanced ability to resist hypoxia. To explore the molecular mechanisms underlying the enhanced hypoxia tolerance of GBSB as a result of gynogenesis, in the present study, we conducted the comparative analyses of the liver transcriptomes of GBSB and BSB under normoxic conditions and identified differentially expressed genes (DEGs). Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that many DEGs were enriched in the NF-kappa B signaling pathway (flip, nfkb2, cxcl8, il1b, tnfaip3, nfkbia, cox2, pias4, ube2i, malt1), hypoxia-inducible factor-1 (HIF-1) signaling pathway (hif-1α, vegfa, pfkfb2, glut1, hk), FOXO signaling pathway (pi3k, sgk1, foxo1, prmt1, pcka), and glycolysis/gluconeogenesis pathway (pgm, hk, aldo, pcka, gapa, acs). In addition, the average concentration of hemoglobin, which might be related to the NF-kappa B and HIF-1 signaling pathways, was higher in GBSB than in BSB (p < 0.05). This study provided important information regarding the potential molecular mechanisms underlying hypoxia tolerance in the GBSB, presenting further evidence for the enhanced ability to resist hypoxia in GBSB, which is significant for fish genetic breeding.