A pair of primers were designed according to the published nucleotide sequence of a putative outer membrane protein gene(omp) of Aeromonas hydrophila.With the specific primers,a target fragment about 1.1 kb was amplif...A pair of primers were designed according to the published nucleotide sequence of a putative outer membrane protein gene(omp) of Aeromonas hydrophila.With the specific primers,a target fragment about 1.1 kb was amplified from Aeromonas hydrophila ML316 via PCR.The target fragment was inserted into the linearized pGEM-T easy vector.After enzyme restriction and sequencing analysis,the nucleotide data had been further analyzed by DNAman and ClutalW software.The analysis results showed that the cloned DNA fragment had a longest open reading frame(ORF) of 1035 nt,it predicted to be encoded a 344-aa protein with the molecular weight of 36 kD.Hydrophobicity analysis suggested that the protein was highly hydrophilic,especialy at the first 24 amino-acid,this region could function as signal peptide.The homologious comparison proved the cloned gene had 96% homology to the sequence of the omp gene,and the alignment of the amino acid sequence was 98%.The recombinant plasmid was constructed with the target gene and the expressing vector pGEX-4T-1 and then was transformed into E.coli BL21(DE3)by BamH and Sal I.The fusion protein was expressed under the IPTG inducing condition,and exhibited about 62 kD in size,very close to the predicted molecular weight of GST-MOMP,furthermore,the fusion protein was specifically recognized by anti-serum which raised against the major outer membrane protein of AHML316.Considering all these together,it proved that the cloned gene represented the major outer membrane protein gene of AHML316,and the expressed gene products shared identical antigenicity with the natural main outer membrane protein,and also provided technical support for developing an advanced gene engineering vaccine against Aeromonas hydrophila.展开更多
最近阐明了水华蓝藻噬藻体PaV-LD(Planktothrix agardhii Virus isolated from Lake Donghu)的全基因组序列,这是一个含有142个ORF的双链DNA噬藻体。在此,我们对其主要衣壳蛋白基因073R,内肽酶和穿孔素基因123L-124L(PaV-LD基因组中两...最近阐明了水华蓝藻噬藻体PaV-LD(Planktothrix agardhii Virus isolated from Lake Donghu)的全基因组序列,这是一个含有142个ORF的双链DNA噬藻体。在此,我们对其主要衣壳蛋白基因073R,内肽酶和穿孔素基因123L-124L(PaV-LD基因组中两个相邻的ORF)进行了基因克隆与表达分析。将073R克隆后构建原核表达质粒pET-32a-073R,并用IPTG进行诱导表达,073R融合蛋白经纯化后,进行免疫小鼠制备抗体;通过Western blot检测经噬藻体感染宿主细胞后073R的表达时序,结果显示在宿主细胞裂解之初,即PaV-LD感染48h以后073R开始表达,表明073R是一个晚期基因;同时073R推导的氨基酸序列与34株噬藻(菌)体及2株藻病毒(感染真核藻的病毒)的主要衣壳蛋白的氨基酸序列进行序列比对,显示073R与无尾的藻病毒衣壳蛋白亲缘关系更近。PCR扩增内肽酶和穿孔素基因123L-124L,并构建质粒pOP123L-124L,将其转入模式藻集胞藻PCC6803细胞中,质粒pOP123L-124L与藻集胞藻PCC6803基因组发生重组,形成重组藻;测定了重组藻与野生藻的生长速率,并绘制生长曲线;制备超薄切片,进一步比较和观察重组藻与野生藻的超微结构的变化。结果显示重组藻与野生藻存在生长速率与超微形态的显著差异。展开更多
根据GenBank中已发表的鸭科(Anatidae)雁属水禽主要组织相容性复合物Ⅰ(major histocompatibility complexⅠ,MHCⅠ)基因的多重比对确定保守序列,用Primer Premier 5.0软件在保守序列区域设计1对特异性引物,从快长系F1鹅的基因组DNA中...根据GenBank中已发表的鸭科(Anatidae)雁属水禽主要组织相容性复合物Ⅰ(major histocompatibility complexⅠ,MHCⅠ)基因的多重比对确定保守序列,用Primer Premier 5.0软件在保守序列区域设计1对特异性引物,从快长系F1鹅的基因组DNA中扩增获得MHCⅠ基因片段序列,采用DNAsis、Mega 5.10、BLAST等多种生物学软件对核苷酸序列和氨基酸序列的结构、性质和功能进行分析。结果显示,克隆的F1鹅MHCⅠ基因片段长1036bp,编码96个氨基酸,与NCBI中五龙鹅MHCⅠ基因和编码序列的同源性达93%和83%,有72处碱基序列不同,16个氨基酸发生改变。与其他家禽也有较高的同源性,亲缘关系依次为四季鹅>鸡>鸭。F1鹅MHCⅠ基因片段编码蛋白分子质量为11.342ku,PI值为5.32,不稳定系数为34.92,脂肪系数为42.81,平均疏水性为-1.066,可能存在9个B细胞抗原表位,但不含信号肽,提示该蛋白为亲水性的非分泌蛋白,具有较高的免疫原性。在蛋白的二级结构中α-螺旋占31.25%,β-折叠占16.67%,β-转角占14.58%,无规则卷曲占37.50%,三级结构呈现近似哑铃型,具有2个结构域:氨基末端结构域和羧基末端结构域。因此,环境中的病原压力使MHC基因在物种之间和种群的个体之间都产生了明显差异,存在着多态性MHC分子与多样性抗原肽相互作用的关系。MHC决定着疾病易感性个体的差异,是研究疾病抗性的最佳候选标记基因。展开更多
文摘A pair of primers were designed according to the published nucleotide sequence of a putative outer membrane protein gene(omp) of Aeromonas hydrophila.With the specific primers,a target fragment about 1.1 kb was amplified from Aeromonas hydrophila ML316 via PCR.The target fragment was inserted into the linearized pGEM-T easy vector.After enzyme restriction and sequencing analysis,the nucleotide data had been further analyzed by DNAman and ClutalW software.The analysis results showed that the cloned DNA fragment had a longest open reading frame(ORF) of 1035 nt,it predicted to be encoded a 344-aa protein with the molecular weight of 36 kD.Hydrophobicity analysis suggested that the protein was highly hydrophilic,especialy at the first 24 amino-acid,this region could function as signal peptide.The homologious comparison proved the cloned gene had 96% homology to the sequence of the omp gene,and the alignment of the amino acid sequence was 98%.The recombinant plasmid was constructed with the target gene and the expressing vector pGEX-4T-1 and then was transformed into E.coli BL21(DE3)by BamH and Sal I.The fusion protein was expressed under the IPTG inducing condition,and exhibited about 62 kD in size,very close to the predicted molecular weight of GST-MOMP,furthermore,the fusion protein was specifically recognized by anti-serum which raised against the major outer membrane protein of AHML316.Considering all these together,it proved that the cloned gene represented the major outer membrane protein gene of AHML316,and the expressed gene products shared identical antigenicity with the natural main outer membrane protein,and also provided technical support for developing an advanced gene engineering vaccine against Aeromonas hydrophila.
文摘最近阐明了水华蓝藻噬藻体PaV-LD(Planktothrix agardhii Virus isolated from Lake Donghu)的全基因组序列,这是一个含有142个ORF的双链DNA噬藻体。在此,我们对其主要衣壳蛋白基因073R,内肽酶和穿孔素基因123L-124L(PaV-LD基因组中两个相邻的ORF)进行了基因克隆与表达分析。将073R克隆后构建原核表达质粒pET-32a-073R,并用IPTG进行诱导表达,073R融合蛋白经纯化后,进行免疫小鼠制备抗体;通过Western blot检测经噬藻体感染宿主细胞后073R的表达时序,结果显示在宿主细胞裂解之初,即PaV-LD感染48h以后073R开始表达,表明073R是一个晚期基因;同时073R推导的氨基酸序列与34株噬藻(菌)体及2株藻病毒(感染真核藻的病毒)的主要衣壳蛋白的氨基酸序列进行序列比对,显示073R与无尾的藻病毒衣壳蛋白亲缘关系更近。PCR扩增内肽酶和穿孔素基因123L-124L,并构建质粒pOP123L-124L,将其转入模式藻集胞藻PCC6803细胞中,质粒pOP123L-124L与藻集胞藻PCC6803基因组发生重组,形成重组藻;测定了重组藻与野生藻的生长速率,并绘制生长曲线;制备超薄切片,进一步比较和观察重组藻与野生藻的超微结构的变化。结果显示重组藻与野生藻存在生长速率与超微形态的显著差异。
