【摘要】 利用RT -PCR技术 ,合成并扩增了水稻条叶枯病毒 (RStV)中国云南分离物基因组组分 3的全长cDNA。将PCR产物克隆在载体 pCRⅡ上 ,进行全序列测定。将所得核苷酸序列及其所推导的氨基酸序列与日本分离物T进行同源性比较 ,结果表明 ,在核苷酸水平上 ,两分离物的 5′端非编码区序列相同 ,vORF、vcORF及基因间非编码区序列的同源性分别为 97 6 %、96 8%及 87 6 % ,而 3′端非编码区同源性为 98 9% ,仅有一个核苷酸不同 ;在氨基酸水平上 ,vORF及vcORF编码蛋白的同源性分别为 99 1%和 98 5 %。可见编码区的大小及其氨基酸序列和两末端序列都是很保守的。序列分析显示 ,两个RStV分离物的RNA3均有双义编码特性。因此 ,中国云南分离物Y与日本分离物T可能有很近的亲缘关系。更多还原

【Abstract】 The cDNA fragment covering full length sequence of RStV RNA3 of Yunnan isolate in China was obtained by RT PCR. The PCR derived fragment was then cloned into vector pCRII. The cloned cDNA was sequenced. Comparison of the nucleotide and deduced amino acid sequences with those of the Japanese isolate T was made. The results showed that at the nucleotide level, vORF, vcORF and the intergenic region had 97.6%, 96.8%, and 87.6% identity respectively, the 5’ untranslational region was exactly the same as that of the Japanese isolate T, while the 3’ terminal sequence had 98.9% identity, differing by one nucleotide; at the amino acid level, vORFr and vcORF had 99.1% and 98.5% identity respectively. Therefore, as well as being exactly the same size for the two isolates, the amino acid sequences of the coding regions and the 5’ and 3’ terminal sequences were well conserved. Our results indicated that the Chinese isolate Y is closely related to the Japanese isolate T.更多还原