【摘要】 根据已知禽流感病毒(AIV)的8个基因序列设计合成12对特异引物,通过反转录—聚合酶链式反应(RT-PCR)技术,分别成功扩增出分离于野鸭(Mallard)的1株H3N8亚型禽流感病毒的全基因片段,将其分别克隆到pMD18-T载体后进行序列测定。同时将8个基因片段与GenBank发表的相应序列进行比较,绘制各基因的进化树。结果表明:所克隆到的8个片段均包含相应病毒基因的完整开放阅读框架,长度分别为PB2/2280、PB1/2276、PA/2150、HA/1734、NP/1497、NA/1413、MP/759、NS/838bp核苷酸,分别编码759、758、716、577、498、4702、52/962、30/125个氨基酸。A/mallard/Sanjiang/359/2007(H3N8)株HA有7个潜在糖基化位点;在HA裂解位点序列为PEKQTR↓GLF,无连续的多个碱性氨基酸插入,具有典型的低致病性禽流感病毒特征。根据A/mal-lard/Sanjiang/359/2007(H3N8)株与参考毒株的序列比较分析结果推测,该分离株可能是不同亚型禽流感病毒通过互相基因交换所形成的基因重组体。更多还原

【Abstract】 Reverse transcription-polymerase chain reaction(RT-PCR) was used to amplify the full-length cDNAs of an avian influenza virus(AIV) isolated from a Mallard.Furthermore,the cDNAs were cloned into pMD18-T and then sequenced.These sequences were compared with the corresponding sequences published in GenBank,and phylogenetic trees were drawn.Results show that eight cDNA fragments all contain the whole open reading frame of corresponding gene,which are composed of PB2/2280,PB1/2276,PA/2150,HA/1734,NP/1497,NA/1413,MP/759 and NS/838 nucleotides,respectively encoding 759,758,716,577,498,470,252/96 and 230/125 amino acids residues.There are seven potential glycosylation sites in HA gene.The amino acid sequence of the cleavage site between HA1 and HA2 is PEKQTR↓GLF,with the typical characteristics of the low pathogenic avian influenza virus.The results of comparative sequence analysis indicate that the gene of the isolate is recombinant.更多还原