Characterization of the CnMnSOD in response to lower temperature stress in noble scallop Chlamys nobilis with different carotenoids content

Abstract

Manganese-superoxide dismutases (MnSODs) play vital roles in immune response and maintaining cellular physiology. In this study, a novel MnSOD (CnMnSOD) gene from noble scallop Chlamys nobilis was first cloned. The full-length cDNA sequence of CnMnSOD contains a 681 bp ORF with 226 amino acids and includes two highly conserved domains, a SOD Fe-N domain and a SOD Fe-C domain. Multiple sequence alignment and phylogenetic analysis showed CnMnSOD was highly conserved to other mollusks. Tissue expression analysis showed CnMnSOD had a significant difference between golden and brown scallops. The transcript level of CnMnSOD in blood, mantle and gill of golden and brown scallops was all significant up-regulated (p < 0.05) under lower temperature stress, and a more interesting finding was that golden scallops had a significantly higher expression levels in mantle and gill (p < 0.05) than those of brown scallops under lower temperature stress. Furthermore, analysis of variance showed the genetic and temperature stress all had significant effects on the expression level of CnMnSOD, and the interaction between them was also significant (p < 0.05). Collectively, these results indicated that CnMnSOD and carotenoids play important roles in the antioxidant system defence against the lower temperature stress, and the carotenoids in scallop may enhance the resistance by up-regulating genes related to innate immunity. These results will deepen our understanding to innate immune response of scallop under low-temperature stress.