Effect of cadmium on oxidative stress and immune function of common carp (Cyprinus carpio L.) by transcriptome analysis.

Cadmium (Cd) is an increasingly important environmental pollutant which causes irreversible toxicity to fish. To understand how Cd impacts the immune response and oxidative stress in common carp, we performed transcriptomic profiles for head kidney, the immune organ of common carp which were underwent Cd exposure. Totally there are 42,489,124 and 48,562,526 high quality clean reads obtained from the Cd exposure groups, and 44,677,578 and 44,106,696 clean reads from the control groups. Among them, 308 genes were differently expressed, including 101 upregulated and 207 down-regulated genes. The identified genes were enriched using databases of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Antioxidant systems and immune function genes and pathways were identified and validated by quantitative real-time RT-PCR. Our results showed that Cd exposure leads to oxidative stress and immunosuppression in head kidney of common carp. These results provide new insights for unveiling the biological effects of Cd in common carp.