Sequence features and functional analysis of the C-type lectin gene (PoLEC1) from pearl oyster Pinctada fucata

Pinctada fucata is one of the main shellfishes which produce sea water pearls,and it has high economic value.Shellfish diseases continuing to occur in recent years,we had to strengthen to study the immune system of shellfish.In this test,through researching the related genes C-type lectin from P.fucata, provided some basic theories of molecular assisted selection for P.fucata. We identified and cloned the cDNA of the C-type lectin gene(PoLEC1)from P.fucata by the cDNA library of P.fucata. Sequence analysis showed that PoLEC1 is 998 bp long,a 5′-UTR is 33 bp,and a 3′-UTR is 101 bp,open reading frame is 864 bp,encoding 287 amino acids,the molecular weight is 31.68 ku and the theoretical isoelectric point is about 5.83.The signal peptide in the predicted amino acid is the Met¹-Ser¹⁹,also contains sugar binding sites.Homology analysis showed that the homology of PoLEC1 and other species.Amino acid sequence is between 18.8% and 28.6%,the similarity is between 28.9% and 50.0%.The phylogenetic analysis showed that the PoLEC1 shared the same branch with Chlamys farreri. Tissue expression analysis showed that the PoLEC1 mRNA was expressed in digestive gland,mantle,gonad,adductor muscle,intestine,gills and hemolymphe.Digestive gland expression analysis showed that after stimulation by Vibrio alginolyticusit was significantly reduced in 2 h,and expression was up-regulated in 4 h and 24 h.The prokaryotic expression vector of PoLEC1 was constructed using the mature peptide,and expressed in E.coli. After the preparation of inclusion bodies,purified by IDA HisBind resin and a single protein.And the coagulation test showed that the protein can agglutinate the E.coli significantly.