A new heat shock protein 70 gene (HSC70) and its expression profiles in response to cadmium stress and after different post-moulting times in Exopalaemon carinicauda (Holthuis, 1950) (Decapoda, Palaemonidae)

In this study, the full-length cDNA sequence (GenBank accession number AGF80339.1) encoding a novel heat shock protein HSP70 family member (Heat shock cognate 70, EcHSC70) was cloned from the ridgetail white prawn, Exopalaemon carinicauda (Holthuis, 1950) [currently also as: Palaemon carinicauda Holthuis, 1950]. EcHSC70 full-length cDNA consists of 2452 bp, containing an open reading frame (ORF) of 1935 bp, and it encodes a 650-amino-acid protein with a theoretical size of about 71 kDa and a predicted isoelectric point of 5.32. Phylogenetic analysis showed that EcHSC70 can be categorized together with the known HSP70 family members reported in other crustaceans. Tissue-expression analysis revealed that EcHSC70 was constitutively expressed in all of the tested tissues, with a significantly increased expression in the gill post-moulting. Moreover, the relative mRNA level of EcHSC70 tended to increase in the early stages of post-moulting (from 0 to 5 min), suggesting that EcHSC70 might take part in the recovery of E. carinicauda after moulting. In addition, under different levels of cadmium stress, EcHSC70 tended to be significantly expressed only after 24 h of cadmium exposure, and was more inducible by low concentrations of cadmium, as opposed to high concentrations.