Comparative transcriptome analysis in the hepatopancreas of Helice tientsinensis exposed to the toxic metal cadmium.

Abstract

The mudflat crab Helice tientsinensis is one of the most commercially valuable species for crabmeat production due to its delicious taste. These crabs are mainly found in coastal wetland where they are seriously threatened by toxic heavy metal pollution. In crustaceans, the hepatopancreas is an important organ for detoxification, and metal toxic substances can be converted to non-toxic or less toxic compounds in this organ. To develop a better understanding of the molecular response of H. tientsinensis to the toxic metal cadmium (Cd) and provide a molecular basis for the toxic metal tolerance of H. tientsinensis. In this study, we performed comparative hepatopancreas transcriptome analysis between H. tientsinensis unexposed (as control) and exposed to the toxic metal Cd for 48h. We identified 1089 Cd stress significantly-upregulated and 1560 Cd stress significantly-downregulated unigenes. Functional categorization and annotation of these differentially-expressed genes (DEGs) demonstrated that the response to Cd stress in the hepatopancreas of H. tientsinensis mainly involves "antioxidant activity", "detoxification", "toxin degradation activity" and "immune system process". In addition, five genes (ABCC1, NDUFAF5, ASTL, DES1, CYP27A) were identified as possible major targets for toxic metal tolerance. This is the first time reporting thatthe response of H. tientsinensis to Cd exposure at the transcriptome level, and it lays the foundation for understanding the molecular mechanisms of the response of H. tientsinensis to environmental toxic metal stress.