Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom.
PLoS Comput Biol. 2022 May 10;18(5):e1010125. doi: 10.1371/journal.pcbi.1010125. eCollection 2022 May.
Viral superinfection occurs when multiple viral particles subsequently infect the same host. In nature, several viral species are found to have evolved diverse mechanisms to prevent superinfection (superinfection exclusion) but how this strategic choice impacts the fate of mutations in the viral population remains unclear. Using stochastic simulations, we find that genetic drift is suppressed when superinfection occurs, thus facilitating the fixation of beneficial mutations and the removal of deleterious ones. Interestingly, we also find that the competitive (dis)advantage associated with variations in life history parameters is not necessarily captured by the viral growth rate for either infection strategy. Putting these together, we then show that a mutant with superinfection exclusion will easily overtake a superinfecting population even if the latter has a much higher growth rate. Our findings suggest that while superinfection exclusion can negatively impact the long-term adaptation of a viral population, in the short-term it is ultimately a winning strategy.
病毒的继发感染发生于多个病毒颗粒随后感染同一宿主。在自然界中，人们发现几种病毒已经进化出多种机制来防止继发感染（继发感染排斥），但这种策略选择如何影响病毒种群中突变的命运仍不清楚。通过随机模拟，我们发现继发感染时遗传漂变受到抑制，从而有利于有益突变的固定和有害突变的消除。有趣的是，我们还发现，与生活史参数变化相关的竞争（劣势）优势并不一定与两种感染策略中的病毒增长率相关。综合这些因素，我们发现，即使继发感染的病毒具有更高的增长率，具有继发感染排斥的突变体也很容易超越继发感染的病毒种群。我们的研究结果表明，尽管继发感染排斥会对病毒种群的长期适应产生负面影响，但从短期来看，它最终是一种成功的策略。
