马传染性贫血病毒阿根廷流行毒株前病毒gag和gp90基因在马体内的变异分析

为建立美洲马传贫毒株和我国弱毒疫苗株鉴别诊断PCR，对接种马传贫阿根廷流行毒株后马4个发热期（23、40、51和70d）外周血单核细胞前病毒DNA gag基因和gP90基因的核苷酸序列进行了监测，经过序列分析发现4个发热期中前病毒gag基因核苷酸序列变化不明显，变异率在1％之内，表明前病毒gag基因在马体内比较保守，可以作为设计鉴别诊断引物的区域；gp90区的基因变化比较大，核苷酸序列变异率在8％～10％之间，通过对几个发热期核苷酸序列推导氨基酸的分析，可以划分出A1、A2、A3和A44个可变区，但其中A1和A4变异都很稳定，在马体发病的整个过程中均只发生1次变异，而A2区第3个发热期变异后，在第4个发热期又回复了突变。对马传染性贫血病毒阿根廷代表毒株前病毒gag和gp90基因核甘酸序列的动念检测结果表明，马传贫病毒在马体整合为前病毒之后比较稳定，这就为建立PCR鉴别诊断方法提供了依据。

Dynamic Detection of gag and gp90 Gene of Provious DNA from Equine Infectious Anemia Virus in Argentina Stain Infected Pony

In order to develop an assay to distinguish the infection of EIAV American strains from DLV,the genetic evolution of two main gene gag and gp90 of EIAV proviral DNA were investigated during recurring febrile episodes.The gag and gp90 gene were amplified with proviral DNA from PBMC of EIAV-Argentina infected horse during four febrile episodes(23,40,51 and 70 days post-infection).The results showed that the gag gene was conservative during four febrile episodes,the percentages of variable nucleotide is under 1%,therefore this region can be selected to design the primers for differentiate diagnosis.The variance of gp90 gene was higher at 8%-10%,the comparison of variable nucleotide showed that mutations were not randomly distributed but delineated four variables regions,A1-A4.A1,A4 variables regions mutate just one time during four febrile episodes,while A2 mutate at third febrile episodes then recover at the fourth febrile episode.The study showed that provirus was very steady after EIAV virus integrating into the cell genome,it offer a credible basis for PCR assay of EIAV.