利用反向遗传技术研究H9N2亚型AIV传播途径的分子机制  

Molecular mechanism affecting route of transmission for H9N2 subtype AIV

作　　者：石火英[1] 刘秀梵[1] 

机构地区：[1]扬州大学农业部畜禽传染病学重点开放实验室,扬州225009

出　　处：《微生物学报》2006年第1期48-54,共7页Acta Microbiologica Sinica

基　　金：江苏省属高校重大基础研究项目资助(05KJA23016);农业部资助项目(农办牧200183)~~

摘　　要：利用反向遗传技术,通过基因重排方法,产生两个表面基因来自A/Chicken/Guangdong/SS/94(H9N2)禽流感病毒(avian influenza virus,AIV)株和其余基因来自A/Chicken/Shanghai/F/98(H9N2)AIV株的3株H9N2亚型重排AIV,动物传播性试验发现A/Chicken/Shanghai/F/98(H9N2)株、A/Chicken/Guangdong/SS/94(H9N2)AIV株和3株H9N2亚型重排AIV都可以经直接接触途径传播;在粪便接触途径下,3株重排AIV都不经粪便接触传播;只有A/Chicken/Shanghai/F/98(H9N2)株和重排AIV RF7/SSHA能经过气溶胶途径传播。HI试验结果进一步证明了以上的结果。实验结果表明H9N2亚型AIV的NA基因与H9N2亚型AIV气溶胶传播途径有重要的关系,即1998年中国大陆H9N2亚型AIV大流行可能是因为病毒获得气溶胶传播途径的特性,推测病毒的NA基因发挥了重要作用。The available evidence suggests that H9 subtype avian influenza virus （AIV） did not circulate in Chicken flocks in China until the early 1990s. However, the pandemic of H9 subtype AI, which started in summer of 1998, spread very rapidly to more than 20 provinces within several months. Obviously, the virus responsible for the 1998 pandemic was quite different from the virus isolated in early 1990s. In order to investigate the molecular mechanism affecting the route of transmisson for H9N2 AIVs, strains of A/Chicken/Guangdong/SS/94 （H9N2） （SS） and A/Chicken/ Shanghai/F/98 （H9N2） （F） were compared in their route of transmisson. SS strain representing the earlier strain was isolated in chickens in Guangdong province in 1994, whereas F strain was isolated in Shanghai during 1998 pandemic. The findings suggested that F strain could transmitted in chickens by direct contact and by aerosol route. Whereas SS strain only by direct contact, and neither of two viruses by fecal contact. The cDNAs derived from the HA and NA genes of SS strain were chined into vector pHW2000 to construct two transcription/expression plasmids respectively, and the cDNAs derived from 8 genes of F strain was done in the same way. Three recombinants were generated by reverse genetics： RF7/SSHA with the HA gene from SS strain and the remaining seven genes from F strain, RF7/SSNA with the NA gene from SS strain and the remaining seven genes from F strain, and RF7/SSHA/SSNA with the HA and NA genes of SS strain and the remaining six genes from F strain. In order to identify three recombinants, a total of seven genes from them were amplified by using PCR with universal primer pairs of H9N2 influenza virus and sequenced. In addition, three recombinants were characterized by HA and HI tests and sequence analysis. The results indicated that three recombinants were successfully rescued by reverse genetics. To determine the genes associated with the ability to transmit by aerosol route in chickens, a set of transmission experiments wer

关 键 词：AIV H9N2亚型 传播途径 反向遗传技术 HA和NA基因 

分 类 号：S852.65[农业科学—基础兽医学]