Molecular characterization and expression analysis of heat shock cognate 70 after heat stress and lipopolysaccharide challenge in sea cucumber (Apostichopus japonicus)

摘要

A gene encoding hsc70 was cloned from the sea cucumber Apostichopus japonicus and named AjHsc70. The full-length cDNA sequence was 2,508 bp, containing a 5′-UTR of 77 bp, an ORF of 2,010 bp encoding 670 amino acids, and a 3′-UTR of 421 bp. Quantitative RT-PCR analysis revealed that AjHsc70 was expressed constitutively in all of the tested tissues with respiratory tree tissue showing the highest expression level. AjHsc70 expression was significantly induced by lipopolysaccharide, and the expression levels peaked at different sampling times in the body wall (24 h), coelomocytes (12 h), and intestine and respiratory tree tissues (6 h). After heat stress, AjHsc70 expression in intestine, coelomocytes, and body wall decreased acutely at first and then increased slightly. AjHsc70 expression patterns indicated that hsc70 plays an important role in mediating the responses of A. japonicus to bacterial challenge and heat stress.