iTRAQ-based quantitative proteomics reveals the biochemical mechanism of cold stress adaption of razor clam during controlled freezing-point storage

Razor clam is a major cultivated shellfish of great economic importance and high nutritional value. Due to high corruptible potential, razor clam is generally preserved by controlled freezing-point storage (CFPS). Here, we applied isobaric tags for relative and absolute quantification (iTRAQ) labeling to investigate the biochemical mechanism of cold stress adaption in razor clam during CFPS. In total, 369 proteins were quantified, and 27 of them were identified as differentially expressed proteins during CFPS, mostly involved in energy metabolism process, DNA duplication and protein synthesis, and stress response, specifically, MAPK is the predominant pathway. Further qPCR results revealed H2A and S6K 2 alpha to be the critical post-transcriptionally regulated genes. Our results provided proteomics information with respect to the biochemical mechanism of cold stress adaption in razor clam, shed light on the further elongation of razor clams storage period, and help clarify the novel mechanisms of cold tolerance.