Cloning and respond of a cold shock domain protein (CnCSDP) gene to cold stress in noble scallop Chlamys nobilis (Bivalve: Pectinidae).

Cold shock domain proteins (CSDPs) play various roles in cellular processes, including adaptation to low temperature in mollusk. In this study, the cDNA encoding CSDP in noble scallop Chlamys nobilis was cloned (CnCSDP), and its transcript profile in cold-stressed orange and brown strains was analyzed using real-time RT-PCR. Bioinformatic analysis shows that the complete CnCSDP cDNA is 1,434 bp in length, consisting of a 5'-, and 3'-untranslated region of 86 and 466 bp, respectively, and a 882 bp open reading frame encoding 294 amino acids with an estimated molecular mass of 33.23 kDa and an isoelectric point of 9.72. Furthermore, CnCSDP has two consensus RNA binding domains, four DNA binding sites and four RGG repeats. CnCSDP transcripts amount in the blood of orange strain were significantly higher, while in the mantle were much lower than that of brown strain. In the cold-stressed orange strain, CnCSDP mRNA decreased dramatically in the blood and mantle, but was significantly up-regulated at 1 h, and progressively returned to its original levels in the gill. In the cold-stressed brown strain, CnCSDP transcripts were significantly up-regulated at 6 h in the blood, decreased dramatically in the mantle, while mostly maintained unchanged in the gill. Lastly, significantly positive correlation was found between the CnCSDP transcripts amount and total carotenoids content in the gill in both orange and brown strain. This study will be helpful for understanding the molecular mechanism underlying cold stress in noble scallop in the further.