Chen Li, Haiwei Wang, Jiabao Shi, Decheng Yang, Guohui Zhou, Jitao Chang, Craig E. Cameron, Andrew Woodman, Li Yu. Senecavirus-Specific Recombination Assays Reveal the Intimate Link between Polymerase Fidelity and RNA Recombination. J Virol. 2019 Apr 17 -最新论文-中国农业科学院哈尔滨兽医研究所

Chen Li, Haiwei Wang, Jiabao Shi, Decheng Yang, Guohui Zhou, Jitao Chang, Craig E. Cameron, Andrew Woodman, Li Yu

J Virol. 2019 Apr 17. pii: JVI.00576-19. doi: 10.1128/JVI.00576-19. [Epub ahead of print]

Abstract

Senecavirus A (SVA) is a re-emerging virus and recent evidence has emphasized the importance of SVA recombination in vivo on virus evolution. In this study, we report the development of an infectious cDNA clone for the SVA/HLJ/CHA/2016 strain. We have used this strain to develop a reporter virus expressing eGFP, which we then used to screen for a recombination-deficient SVA by an eGFP-retention assay. Sequencing of the virus that retained the eGFP following passage allowed us to identify the non-synonymous mutations (S460L alone and I212V/S460L in combination) in the RNA-dependent RNA polymerase (RdRp) region of the genome. We developed a Senecavirus specific cell culture based recombination assay, which we used to elucidate the role of RdRp in SVA recombination. Our results demonstrate that these two polymerase variants (S460L and I212/S460L) have reduced recombination capacity. These results indicate that the RdRp plays a central role in SVA replicative recombination. Notably, our results showed that the two recombination-deficient variants are of higher replication fidelity, and display decreased ribavirin sensitivity. In addition, these two mutants exhibited significantly increased fitness in vitro These results demonstrate that recombination and mutation rates are intimately linked. Our results have important implications for understanding the crucial role of the RdRp in virus recombination and fitness, especially in the molecular mechanisms of SVA evolution and pathogenicity.IMPORTANCE Recent evidence has emphasized the importance of SVA recombination on virus evolution in vivo We describe the first assays to study Senecavirus A recombination. Results showed that the RNA-dependent RNA polymerase plays a crucial role in recombination and that recombination can impact fitness of SVA in cell culture. Further, the SVA polymerase fidelity is closely related to the recombination efficiency. The results provide key insights into the role of recombination in positive-strand RNA viruses.