摘要
测定了来源于我国水稻条纹叶枯病常年流行区的云南楚雄(CX)及病害暴发区的江苏洪泽(HZ)的水稻条纹病毒(RSV)2个分离物RNA2全长序列,其长度分别为3506bp和3514bp。与已报道的日本T和O分离物RNA2序列进行比较的结果表明,这4个分离物可分为两组,其中,HZ、T和O分离物为一组,组内分离物之间,RNA2的毒义链(vRNA2)及RNA2的毒义互补链(vcRNA2)上的ORF的核苷酸一致性分别为97.2％～98.0％和96.8％～97.1％,5′端和3′端非编码区的序列则完全一致。但HZ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和O分离物的等长。另一组为我国CX分离物,组与组之间,vRNA2及vcRNA2上的ORF的核苷酸一致性分别为95.0％～95.7％和93.9％～94.4％。CX分离物的IR与HZ分离物相比缺失了一段8nt的片段。5′端非编码区的序列完全一致,但3′末端非编码区有一个碱基的差异。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能。本文还讨论了RSV的分子流行病学。
The complete nucleotide sequences of the RNA2 of two Chinese isolates of Rice stripe virus are determined. One is isolated from endemic sites at Chuxiong (CX), Yunnan Province, the other is isolated from outbreak sites at Hongze (HZ), Jiangsu Province. The total nucleotide sequences of the RNA2 of RSV CX and RSV HZ are 3506 bp and 3514 bp long, respectively. When compared with RNA2 of T and O isolates of Japan, we find that these four isolates could be divided into two groups. HZ, T and O isolates share 97.2%～98.0% and 96.8%～97.1% identities in vORF2 and vcORF2 at the nucleotide level, respectively and form one group. The sequences in 5' and 3' terminal non-encoding region are completely identical among these three isolates. In this group, HZ isolate is more closely related to T isolate than to O isolate. The length of intergenic region (IR) of HZ isolate is the same as those of T and O isolates. CX isolate belongs to another group, which shares only 95.0%～95.7% and 93.9%～94.4% sequences identities in vORF2 and vcORF2 between two groups at the nucleotide level, respectively. There is a deletion of 8 nt in length in the IR of CX isolate compared with HZ isolate. Even though no base variation occurred in 5' terminal non-coding region, there is one base substitution in 3' terminal non-coding region between CX and HZ isolates. These results show that the isolates are grouped according to their geographical location. Additionally, highly consensus in 5' and 3' non-encoding region suggests that these regions play a very important role in transcription and replication of viral genome. Finally, the molecular epidemiology and gene functions of RSV are discussed in this paper.
出处
《中国病毒学》
CSCD
2003年第4期381-386,共6页
Virologica Sinica
基金
国家自然科学基金(30000002,30240017)
高等学校全国优秀博士学位论文作者专项资金(200150)
