Institut Pasteur, Viral Populations and Pathogenesis, CNRS URA 3015, 28 rue du Dr Roux, 75724 Paris Cedex 15, France.
J Virol. 2011 Jan;85(2):1025-35. doi: 10.1128/JVI.01918-10. Epub 2010 Nov 3.
The mechanisms by which RNA arboviruses, including chikungunya virus (CHIKV), evolve and maintain the ability to infect vertebrate and invertebrate hosts are poorly understood. To understand how host specificity shapes arbovirus populations, we studied CHIKV populations passaged alternately between invertebrate and vertebrate cells (invertebrate ↔ vertebrate) to simulate natural alternation and contrasted the results with those for populations that were artificially released from cycling by passage in single cell types. These CHIKV populations were characterized by measuring genetic diversity, changes in fitness, and adaptability to novel selective pressures. The greatest fitness increases were observed in alternately passaged CHIKV, without drastic changes in population diversity. The greatest increases in genetic diversity were observed after serial passage and correlated with greater adaptability. These results suggest an evolutionary trade-off between maintaining fitness for invertebrate ↔ vertebrate cell cycling, where maximum adaptability is possible only via enhanced population diversity and extensive exploration of sequence space.
RNA 虫媒病毒（包括基孔肯雅病毒（CHIKV））进化和维持感染脊椎动物和无脊椎动物宿主的能力的机制尚未完全理解。为了了解宿主特异性如何塑造虫媒病毒种群，我们研究了在无脊椎动物和脊椎动物细胞之间交替传代的 CHIKV 种群（无脊椎动物↔脊椎动物），以模拟自然交替，并将结果与通过单一细胞类型传代而从循环中人为释放的种群进行对比。通过测量遗传多样性、适应性和对新选择压力的适应能力来表征这些 CHIKV 种群。在交替传代的 CHIKV 中观察到最大的适应性增加，而种群多样性没有剧烈变化。遗传多样性的最大增加发生在连续传代后，与更大的适应性相关。这些结果表明，在维持适应无脊椎动物↔脊椎动物细胞循环的适应性和适应性方面存在进化权衡，其中最大的适应性仅通过增强种群多样性和广泛探索序列空间来实现。
