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对我国水稻条纹病毒 (RiceStripeVirus,RSV)一个强致病性分离物 (辽宁PJ分离物 )的RNA4区段进行扩增、克隆和测序 ,其核苷酸序列全长 2 1 57bp。与已报道的日本T和M分离物及我国云南CX分离物的RNA4序列进行比较分析 ,结果表明 ,这 4个分离物可分为两组 ,其中 ,PJ、T和M分离物为一组 ,组内分离物之间 ,RNA4的毒义链 (vRNA4)及RNA4的毒义互补链 (vcRNA4)上的ORF的核苷酸一致性分别为 97 0 %和 97 0 %～ 97 5% ,5′末端和 3′末端非编码区的序列则完全一致。但PJ分离物与T分离物的亲缘关系更为密切 ,其基因间隔区 (IR)与T分离物的等长 ,核苷酸一致性为 93 0 % ,比M分离物的IR多了一段长1 9bp的插入序列 ,核苷酸一致性仅为 85 0 %。另一组为我国CX分离物 ,组与组之间 ,vRNA4及vcRNA4上的ORF的核苷酸一致性分别为 94 0 %和 92 5%～ 93 5% ,但在氨基酸水平上则没有明显的差异。CX分离物的IR与PJ分离物相比有一段长 84bp的插入序列 ,组间 ,IR的核苷酸一致性仅为 72 0 %～ 75 0 % ,5′末端非编码区的序列完全一致 ,但 3′末端非编码区有两个碱基的差异。这些结果表明 ,RSV在自然界的分子变异与其地理分布具有密切的关系。此外 ,非编码区序列的高度保守性暗示着它们在病毒基因转录和复制的调控方面具有重要的功
The RNA4 segment of a strongly pathogenic isolate (Liaoning PJ isolate) of rice stripe virus (RSV) in China was amplified, cloned and sequenced. The nucleotide sequence of the full length RNA was 2157bp. Compared with reported T and M isolates in Japan and RNA4 sequences of CX isolates from Yunnan in China, the results showed that the four isolates could be divided into two groups, of which PJ, T and M isolates were a group, The nucleotide identities of the ORFs in the isolates were 97.0% and 97.0% ~ 97.5% respectively for the vRNA4 of RNA4 and vRNA4 of RNA4, The sequences of the terminal and 3 ’non-coding regions are exactly the same. However, the genetic relationship between PJ isolates and T isolates was even closer. The nucleotide identity of PJ isolates was 93 0%, which was more than that of M isolates 1 9bp insertion sequence, the nucleotide identity was only 85%. The other group was CX isolates in China. The nucleotide identity of ORFs between vRNA4 and vcRNA4 was 94 0% and 92 5% ~ 93 5%, respectively, but not at the amino acid level difference. The IR of the CX isolate had a 84bp insertion sequence compared with that of the PJ isolate. The nucleotide identity of the IR between the two groups was only 72.0% -75.0%, and the sequence of the 5 ’end non-coding region was completely identical. However, there is a difference of two bases in the 3’-terminal non-coding region. These results indicate that the molecular variation of RSV in nature is closely related to its geographical distribution. In addition, the high degree of conservation of noncoding region sequences suggests that they have important contributions in the regulation of viral gene transcription and replication