Direct evidence for genome segment reassortment between concurrently-circulating human rotavirus strains
Direct evidence for genome segment reassortment between concurrently-circulating human rotavirus strains
复制标题
同时循环的人类轮状病毒株之间基因组片段重配的直接证据
作者：
M. Watanabe;T. Nakagomi;Y. Koshimura;O. Nakagomi
总结：在A组人轮状病毒中观察到的电泳型的广泛异质性被认为是两种主要机制的结果;即， 点突变的积累和同时循环的菌株之间的遗传重配。然而，迄今为止，没有证据表明任何一种轮状病毒田间分离株是由同时传播的两种亲本毒株直接重配形成的。通过电泳分型和对选定基因片段测序，对6年内收集的人轮状病毒标本的基因组进行比较，发现了两种在同一流行季节共同流行的毒株之间产生的reflectants。这是第一份报告直接表明，至少有一部分的轮状病毒株之间观察到的电泳多样性，解释了基因重排之间的菌株同时在人群中传播。这支持了这样的假设，即共循环毒株之间的遗传重配是自然界轮状病毒遗传变异的关键机制。
Summary. Extensive heterogeneity in electropherotypes observed among group A human rotaviruses has been considered as a result of two major mechanisms; i.e., the accumulation of point mutations and genetic reassortment between concur-rently-circulating strains. However, no evidence was reported thus far indicating that any one of field isolates of rotavirus was formed by direct reassortment of concurrently circulating two parental strains. Comparison of the genome of human rotavirus specimens collected over a six year period by electropherotyping and by the sequencing of selected gene segments identified two reassortants that were generated in nature between strains circulating co-dominantly in the same epidemic season. This is the first report directly showing that at least some part of electrophoretic diversity observed among rotavirus strains was explained by genetic reassortment between strains concurrently circulating in the human population. This supports the hypothesis that genetic reassortment among co-circulating strains operates as a key mechanism for the genetic variability of rotaviruses in nature.