Molecular cloning, characterization and expression of heat shock protein 70 gene from the oyster Crassostrea hongkongensis responding to thermal stress and exposure of Cu2+ and malachite green

► The cDNA of Crassostrea hongkongensis inducible hsp70 (chhsp70) was cloned. ► Sequence analysis results indicated that the ChHSP70 belonged to HSP70 family. ► Expression of chhsp70 rose obviously in gill and digestive gland after heat shock. ► Expression of chhsp70 after Cu2+ and malachite green exposure was measured. ► A time-dependent expression pattern was observed in gill and digestive gland.