Transcriptome analysis of Eriocheir sinensis hemocytes in response to hypoxia

To understand the effect of hypoxia on Chinese mitten crab Eriocheir sinensis, the transcriptomic profiles of hemocytes in the hypoxia (1.5±0.5) mg/L and the normoxia groups (6.0±0.5) mg/L of DO were obtained using Nova Seq 6000. Firstly, by splicing, annotating and screening the original data, in total, 128614 transcripts were obtained with an average length of 2634 bp. Meanwhile, using a 1.2-fold change (P<0.05) in expression as a physiologically significant benchmark. A total of 1687 differentially expressed genes were identified, including 899 up-regulated and 788 down-regulated genes. GO and KEGG analysis showed that many processes or pathways are involved in the crab against hypoxia stress, such as tricarboxylic acid cycle (TCA cycle), glycolysis, ECM-receptor interaction, gap junction, cell apoptosis, prophenoloxidase system (proPO), etc. Finally, ten selected genes from these processes or pathways were verified by qRT-PCR analysis. The results showed 6 up-regulated genes (integrin-β1, extracellular Cu/Zn-superoxide dismutase, phosphoinositide-3 kinase, phosphoglycerate mutase 2, PDGF/VEGF-related factor 1, and relish) and 4 down-regulated genes (innexin-7, 90 ku heat shock, mitochondrial ATP synthase subunit α, and aspartate aminotransferase) corresponded with the transcriptome analysis. This study preliminarily elucidated the molecular mechanism of hemolymph response to short-time hypoxic stress, and provided some valuable information for the further analysis of the mechanism under hypoxia stress in crabs.