H_5N_1亚型禽流感病毒血凝素基因的克隆及分子进化分析

目的　克隆H5N1 亚型禽流感病毒HA基因并进行分子进化分析。方法　应用RT PCR方法 ,以 2株H5N1 亚型禽流感病毒RNA为模板 ,扩增了HA全基因cDNA。将HAcDNA基因克隆于pUCm T载体 ,并对其进行了测序。结果　所克隆的HA基因全长为 1731bp ,共编码 5 6 8个氨基酸。将该毒株与其它 10株H5亚型禽流感病毒HA基因序列核苷酸及氨基酸进行比较 ,其核苷酸同源性在 80 5 %～ 99 2 %之间 ,氨基酸序列同源性在 89 4 %～98 6 %之间。高致病性毒株HA基因裂解位点存在多个碱性氨基酸插入。结论　为禽流感基因工程疫苗的研制奠定了基础 ,同时通过分子进化分析也揭示了各毒株间的亲缘关系。

Cloning and Analysis of Molecular Evolution of Hemagglutinin Gene of Avian Influenza Virus Subtype H5N1

Objective To clone and analyze the molecular ev olut ion of hemagglutinin gene of avian influenza virus (AIV) subtype H 5N 1. Methods The full-length cDNA of hemagglutinin (HA) gene was amplifie d from 2 avian influenza virus isolates (H 5N 1) by RT-PCR,cloned into pUCm- T vector and sequenced. Results The cloned HA gene,at a full-length of 1 731 bp,encoded 56 8 amino acids.The homologies of nucleotide and amino acid sequences of HA genes of the isolates to those of other 10 strains of AIV subtype H5 were 80.5%-99.2% and 89.4%-98.6% respectively.There were 5 basic amino acids inserted into th e cleavage sites of HA gene of highly pathogenic AIV. Conclusion The study laid a foundation of development of recombinant av ian influenza vaccine.Meanwhile,the analysis on molecular evolution indicated th e relationship between various strains of AIV.