Gene Cloning And Functional Studies Of The Matrix Protein CfMSP-1 In Chlamys Farreri

Chlamys farreri is a significant species in aquaculture and fishery in China. In our study, we cloned and studied the biomineralization-related gene-cfMSP-1. Our research contributed to uncovering the biomineralization mechanism of Chlamys farreri.In this study, we cloned an acidic protein(p I = 3.36) homolog of MSP-1 that was highly expressed in the mantle transcriptome of the scallop Chlamys farreri, with using RACE cloning. We got a 2912-bp transcript containing a 5’-untranslated region(UTR) of 74 bp, an open reading frame of 2406 bp(encoding a deduced 802 amino acid protein) and a 3’-UTR of 432 bp. The calculated molecular mass of the deduced mature protein is 71.3 kDa. A 20-aa signal peptide is predicted. At the same time RTPCR and in situ hybridization showed that cf MSP-1 was specifically expressed in the outer fold of the mantle edge and pallial part. The expression level of cf MSP-1 remarkably increased and then reduced gradually to a value which was ~2-fold higher than basal levels after shell notching. Knock-down expression of cf MSP-1 in adults via ds RNA injection gave a disordered folia surface. Both shell notching and RNAi experiments indicated that cf MSP-1 plays an essential role in the formation of the folia of C. farreri.