Wang E, Weaver S C, Shope R E, Tesh R B, Watts D M, Barrett A D
Department of Pathology, University of Texas Medical Branch, Galveston 77555-0605, USA.
Virology. 1996 Nov 15;225(2):274-81. doi: 10.1006/viro.1996.0601.
The nucleotide sequences of three regions of the genomes of 13 yellow fever (YF) virus isolates were determined to define genetic variation and evolution of the virus. Phylogenetic trees generated from sequences of either the 5' terminal 1320 nucleotides of the genome, 754 nucleotides from the NS4A and NS4B genes, or the 3' terminal 511 nucleotides were very similar and contained minor differences. Overall, these results suggested that there were at least four major genotypes of YF virus, including one in Central/East Africa, one in West Africa, and two in South America. Examination of the 3' noncoding region (3'NCR) showed that only West African strains had a 3'NCR of 511 nucleotides while strains from Central/East Africa and South America had shorter 3'NCRs (443-469 nucleotides) due to the absence of YF specific repeat sequences (RYFs). Central/East African strains have two RYFs and West African strains have three RYFs while South American strains only have one copy of the RYF. It is speculated that duplication of the RYF took place in West Africa subsequent to the presumed introduction of YF virus into South America. Thus, both tick-borne (Mandl et al., J. Virol. 65, 4070-4077, 1991 and Wallner et al., Virology 213, 169-178, 1995) and mosquito-borne flaviviruses have variable 3'NCRs.
测定了13株黄热病（YF）病毒分离株基因组三个区域的核苷酸序列，以确定该病毒的遗传变异和进化情况。由基因组5'端1320个核苷酸序列、NS4A和NS4B基因的754个核苷酸序列或3'端511个核苷酸序列生成的系统发育树非常相似，仅存在微小差异。总体而言，这些结果表明黄热病病毒至少有四种主要基因型，包括一种在中非/东非，一种在西非，两种在南美洲。对3'非编码区（3'NCR）的检测显示，只有西非毒株的3'NCR为511个核苷酸，而来自中非/东非和南美洲的毒株由于缺少黄热病特异性重复序列（RYF），其3'NCR较短（443 - 469个核苷酸）。中非/东非毒株有两个RYF，西非毒株有三个RYF，而南美毒株只有一个RYF拷贝。据推测，在黄热病病毒假定传入南美洲之后，RYF在西非发生了重复。因此，蜱传（曼德尔等人，《病毒学杂志》65卷，4070 - 4077页，1991年；瓦尔纳等人，《病毒学》213卷，169 - 178页，1995年）和蚊传黄病毒都有可变的3'NCR。
