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)

Abstract

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 carinicaudaHolthuis, 1950].EcHSC70full-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 thatEcHSC70was constitutively expressed in all of the tested tissues, with a significantly increased expression in the gill post-moulting. Moreover, the relative mRNA level ofEcHSC70tended to increase in the early stages of post-moulting (from 0 to 5 min), suggesting that EcHSC70 might take part in the recovery ofE. carinicaudaafter moulting. In addition, under different levels of cadmium stress,EcHSC70tended 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.