【摘要】 构建了合浦珠母贝(Pinctada fucata)的cDNA文库,并通过EST序列筛选和重新测序获得了一个新的C型凝集素基因的cDNA序列,命名为PoLEC2,其长度为1 659 bp,5’端非编码区为39 bp,3’端非编码区为45 bp,开放阅读框为1 575 bp,可编码524个氨基酸;PoLEC2蛋白的分子量约58.0 kD,等电点为5.2;PoLEC2蛋白包含一个信号肽序列(M1-A16)、一个MAM-2结构域和一个C型凝集素的糖识别结构域。同源性分析结果表明,PoLEC2与其他物种C型凝集素的糖识别结构域序列的同源性在26.5%～33.6%,相似性在45.1%～55.6%。组织表达分析表明,PoLEC2基因在肝胰脏、鳃、外套膜、性腺及肠组织中均有表达,经溶藻弧菌刺激后8h在肠组织中的表达量显著上调。更多还原

【Abstract】 The cDNA library was constructed from the pearl oyster(Pinctada fucata).A C-type lectin gene,named as PoLEC2,was obtained by screening and sequencing using EST sequences.The length of PoLEC2 cDNA sequence was 1 659 bp.Sequence analysis showed that the open reading frame of PoLEC2 gene was 1575 bp.The 5’-UTR length was 39 bp and 3’-UTR length was 45 bp.The PoLEC2 gene encoded a protein containing 524 amino acids,and the predicted molecular weight of PoLEC2 protein was about 58.0 kD with the isoelectric point of 5.2.The protein sequence of PoLEC2 gene contained a signal peptide sequence with 16 amino acids(M1-A16),a MAM-2 domain and a carbohydrate recognition domain of C-type lectin.Sequence analysis showed that the identity and similarity of the carbohydrate recognition domain of PoLEC2 genes between the P.fucata and other organisms were 26.5%~33.6% and 45.1%~55.6% respectively.Tissue expression analysis showed that the PoLEC2 gene was expressed in all tissues of P.fucata,and there was maximum expression in the intestine after 8 hours of the bacterial infection.更多还原