Shanghai Public Health Clinical Center, Fudan University, Shanghai, PR China.
J Gen Virol. 2020 Nov;101(11):1145-1155. doi: 10.1099/jgv.0.001479.
The species ) consists of two conventional clusters and one unconventional cluster. At present, sequence analysis shows no evidence of recombination between conventional and unconventional types. However, the factors underlying this genetic barrier are unclear. Here, we systematically dissected the genome components linked to these peculiar phenomena, using the viral reverse genetic tools. We reported that viral capsids of the unconventional types expressed poorly in human cells. The -encapsidation outputs across conventional and unconventional types were also with low efficiency. However, replicons of conventional types bearing exchanged 5'-untranslated region (UTR) or non-structural regions from the unconventional types were replication-competent. Furthermore, we created a viable recombinant EVA71 (conventional type) with its P3 region replaced by that from EVA89 (unconventional type). Thus, our data for the first time reveal the potential for fertile genetic exchanges between conventional and unconventional types. It also discloses that the mysterious recombination barriers may lie in uncoordinated capsid expression and particle assembly by different clusters.
该病毒株由两个传统簇和一个非常规簇组成。目前，序列分析表明，传统和非常规 型之间没有重组的证据。然而，造成这种遗传障碍的因素尚不清楚。在这里，我们使用病毒反向遗传工具系统地剖析了与这些特殊现象相关的基因组成分。我们报告称，非常规 型的病毒衣壳在人细胞中的表达水平较差。传统和非常规 型的 -衣壳包装效率也较低。然而，具有来自非常规型的交换 5'-非翻译区（UTR）或非结构区的常规型复制子是具有复制能力的。此外，我们创建了一个具有存活能力的重组 EVA71（常规型），其 P3 区域被 EVA89（非常规型）的替换。因此，我们的数据首次揭示了传统和非常规 型之间进行有效基因交换的可能性。这也揭示了神秘的重组障碍可能在于不同 簇之间不协调的衣壳表达和颗粒组装。
