柑橘衰退病毒中国分离物HB1的血清学特性研究

The Study of Serological Property of CP Gene From a Chinese Citrus Tristeza Virus Isolate HB1

利用3种不同来源的柑橘衰退病毒（Citrus tristeza virus,CTV）抗体（PAb-L5、PAb-I、MAbs-S4）对武汉地区发生的CTV进行检测,筛选到一个表现特异血清学性状的分离物CTV-HB1,该分离物仅同来源于中国的多克隆抗体PAb-L5发生血清学反应。为揭示该血清学差异的分子机制,对CTV-HB1和其他几个分离物CP基因序列进行了分析,结果显示：CTV-HB1CP基因与其他19个分离物的核苷酸序列相似性在90.4%-99.4%,但CTV-HB1和CTV-L5的CP基因氨基酸序列间仅存在3个位点的变异,暗示：此3个氨基酸位点可能与CTV-HB1的血清学特性有关。

In this study, a Chinese Citrus tristeza virus（CTV）isolate HB1 showing unusual serological characteristic was identified using three antibodies from different sources （ PAb-LS, PAb-1, MAbs-S4） in Wuhan, Hubei province. CTV- HBI could only be recognized by a polyclonal antibody（PAb-LS）raised against a Chinese isolate L5 in both ELISA and DTBIA. To understand the molecular mechanisms underlying such anomalous serological property, the sequences of CP gene were identified for CTV-HB1 and other isolates. Comparison of the CP gene sequences from CTV-HB1 with those of other 19 isolates published in GenBank revealed that the sequence similarity was 90.4% to 99.4% at nucleotide level. However,only three amino acid residues in the CP gene from CTV-HB1 were different from that of CTV-L5 .All the above results suggested that the three changed position（s）might be correlated to the serological property of CTV-HB1.