cDNA cloning and mRNA expression of heat shock protein 70 gene in blood clam Tegillarca granosa against heavy metals challenge

Abstract

In this study, the full-length heat shock protein 70 of Tegillarca granosa was cloned from cDNA library by rapid amplification of cDNA end (RACE). The open reading frame (ORF) of heat shock protein 70 was 1968 bp, and it encoded a protein of 655 amino acids with a predicted molecular weight of 71.48 kDa and an isoelectric point of 5.25. Basic local alignment search tool (BLAST) analysis showed that the heat shock protein 70 of T. granosa shared high similarity with other species, supporting that it is a new member of heat shock protein family. Western blot analysis revealed that the generated polyclonal antibodies could specially detect native protein from whole cell lysate of T. granosa. The spatial distribution confirmed that the heat shock protein 70 was abundant in visceral mass, gill and haemocytes, and weakly in foot, mantle and adductor. Heavy metal pollutes such as lead (Pb²⁺), cadmium (Cd²⁺) and copper (Cu²⁺) could induce the gene expression in similar manners by quantitative real-time polymerase chain reaction (PCR). The present results indicate that heat shock protein 70 of T. granosa may be involved in environmental pollution challenges and should be considered as one of T. granosa promising molecular marker candidates.

Keywords: Tegillarca granosa, heat shock protein 70, heavy metals, quantitative real-time polymerase chain reaction (PCR)

African Journal of Biotechnology Vol. 12(18), pp. 2341-2352