Abstract:
To investigate the influence of hemoglobin loss on the function of the immune system, gill tissues from Chionodraco hamatus lacking hemoglobin and functional red blood cells, Trematomus bernacchii, Pagothenia borchgrevinki and Notothenia coriiceps with hemoglobin and red blood cells were used for a transcriptome sequencing comparison studies. The results showed that among the 7 498 genes involved in the comparison, 2 796 genes showed significant changes in the gills of Antarctic ice fish, of which 1 584 genes were significantly down regulated and 1 212 genes were significantly up regulated.. KEGG Pathway enrichment analysis of differential genes showed that 33 pathways(Such as the HIF-1 signaling pathway) related to immunity and hypoxia was enriched in gills of Antarctic ice fish. Differential gene GO enrichment analysis also revealed that Antarctic icefish had been enriched in GO pathways(Such as immune system development, homeostatic process and hematopoietic or lymphoid organ development, etc) in multiple biological processes related to immune function and erythropoiesis. It should be noticed that many of the genes(such as gata1 a, tfr1 a, kmt2 a, slc4 a1 a, myb, alas2, epor,slc25 a37 and metap2 a, etc) with decreased expression in gills of Antarctic ice fish were associated with immune function and erythropoiesis, which was consistent with the inhibition of erythropoiesis of Antarctic ice fish. It is concluded that there are significant differences in the expression of genes in the gill tissue between Chionodraco hamatus and the other three Antarctic fish, which provides reference for revealing the evolution of the immune mechanism of Antarctic fish.