马传染性贫血病毒env gp90基因在实验感染马体内的遗传变异(英文)

Proviral Genomic Variation of EIAV Envelop gp 90 Gene Observed in Experimentally Infected Horse

为确定马传染性贫血病毒（ＥＩＡＶ）ｅｎｖｇｐ９０基因的遗传变异特性，本研究应用ＥＩＡＶ日本分离强毒株Ｐ３３７－Ｖ７０实验感染了１匹健康马，经第２次感染后，实验马未呈现临床症状。ｇｐ９０基因的核苷酸序列被直接从这匹马的外周血和肝脏所获得的前病毒ＤＮＡ扩增。通过克隆和测序从这匹马获得了覆盖ＥＩＡＶｇｐ９０基因主要中和抗原功能区（ＰＮＤ）的１７个前病毒序列。通过对这些序列的比较分析，发现一些序列在ＰＮＤ功能区含有核苷酸的插入变异。为揭示ＰＮＤ基因中插入基因片段的产生原因，应用计算机软件对这些片段可能的复制和片段的移位进行了推测。结果显示，这些不同长度的基因插入片段可能是由于其ＰＮＤ基因序列片段的直接重复和移位所产生。鉴于本研究所作序列分析的ＥＩＡＶ变异株是从感染马组织直接获得的，而ＥＩＡＶ的基因组结构在慢病毒中较为简单，故可作为感染模型用于慢病毒持续感染机理的研究。

The present experiment was designed to observe the genetic variation of equine infectious anemia virus (EIAV) envelop gp 90 gene in infected horse. One horse was infected experimentally with P337V70 strain and showed no clinical signs after being infected at twice with the same virus strain. Seventeen proviral sequences covering principal neutralizing domain (PND) of EIAV gp 90 gene were obtained from the buffy coat and liver of the horse through PCR amplification and cloning. Comparative analysis of the sequences revealed that some sequences contained the nucleotide insertions in the PND region. The insertions might be generated by direct repeat and strand displacement of sequence segment in their PND gene, showing different lenghts.