摘要
目的:通过对人禽流感H5N1毒株PB2基因序列的因H变异分析,揭示毒株PB2基因特征与进化.方法:检测广东地区人禽流感H5N1毒株PB2基因核苷酸序列,同时检索全球人禽流感H5N1毒株PB2基因序列,采用DNAStar5.0软件对检索的人禽流感H5N1毒株PB2基因核苷酸序列进行比对和分析;并结合流行病学资料对变异毒株进行进化速度分析.结果:1997/200648株毒株PB2基因核苷酸序列同源性分成两组,1997/1998毒株为第一组(G1),2003/2006毒株为第二组(G2).PB2基因错义置换导致101个氨基酸位点变异,占比例13.3%(101/759).PB2基因Ks值为39.4×10-6～63.4×10-6Nt/d,Ka值为3.36×10-6～5.11×10-6Nt/d;提示PB2基因进化主要受到自发突变影响.2003/2006毒株(包括毒株GD-01-06)仅保留一个糖基化位点(NPT301-303),丢失3个糖基化位点,可能影响蛋白致病性和抗原性.结论:目前PB2基因进化分成两组,主要受到除自发突变影响;PB2基因丢失3个糖基化位点可能影响蛋白致病性.人禽流感H5N1毒株PB2基因在自然界变异非常频繁,不断变异将影响H5N1毒株在人-人传播能力和引发大流行.
AIM： To reveal characteristics and evolutions of PB2 genes of human avian HsNl influenza strains by analysis on sequences of PB2 gene. METHODS： The PB2 gene of human avian HsNl influenza in Guangdong was sequenced and the global PB2 genes of strains were searched out from intemet. They were analyzed by DNAStar 5.0 by means of studying the revolutionary speeds combining the epidemiological data. RESULTS： PB2 genes of 48 strains during 1997 -2006 were homologously classified into two groups： strains during 1997- 1998 （G1）, strains during 2003 -2006 （G2）. There were 101 substitutions of amino acids in PB2 in all strains, accounting for 13.3% （101/759）. In the variation, Kss in PB2 were 39.4 × 10^-6 ～63.4 × 10^-6 Nt/d and Kas in PB2 were 3.36× 10^-6 ～5. 11×10^-6 Nt/d, which indicated that evolution of PB2 genes obviously resulted from spontaneously mutation. The PB2 genes of strains during 2003 - 2006 （including GD-01-06） only remained a glyeoprotein domain （NPT301-303） and deleted other three glyeoprotein domains, which might have an impact on the strain pathogenicity. CONCLUSION： PB2 genes are classified into two groups and they evolve rapidly in genes by spontaneously mutation. The deletion of three glyeoprotein domains in PB2 genes might result in variation of the strain pathogenicity, including the probability of human-human transmission and initiating a new pandemic of human avian H5N1 influenza.
出处
《第四军医大学学报》
北大核心
2007年第17期1547-1550,共4页
Journal of the Fourth Military Medical University
基金
广东科技项目(2004A2090102)
广东省重点科技项目(2003B60127)
关键词
人禽流感
H5N1毒株
PB2基因
进化
特性
human avian influenza
H5N1 strain
PB2 gene
evo lution
characteristic
