Genetic Drift during Systemic Arbovirus Infection of Mosquito Vectors Leads to Decreased Relative Fitness during Host Switching.
Genetic Drift during Systemic Arbovirus Infection of Mosquito Vectors Leads to Decreased Relative Fitness during Host Switching.
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DOI：
10.1016/j.chom.2016.03.002
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发表时间：
2016-04-13
影响因子：
30.3
通讯作者：
Ebel GD
中科院分区：
文献类型：
--
作者：
Grubaugh ND;Weger-Lucarelli J;Murrieta RA;Fauver JR;Garcia-Luna SM;Prasad AN;Black WC 4th;Ebel GD
蚊子传播的RNA病毒（如西尼罗河病毒（WNV））的出现是由宿主内遗传复杂的病毒群体促进的。在这里，我们确定是否WNV地方病（跗库蚊，Cx。quinquefasciatus和Cx. pipiens）和桥载体（Aedesaegypti）对病毒突变多样性和适应性具有不同的影响。在系统性蚊子感染期间，西尼罗河病毒面临着遗传多样性的随机减少，这种减少在组织内种群扩张期间迅速恢复。有趣的是，这种宿主内选择和多样化是蚊子物种依赖与Cx。tarsalis和Cx. quinquefasciatus表现出更大的WNV分歧。然而，与输入病毒相比，回收的病毒群体含有潜在有害突变的优势（即高突变负荷），并且在禽类细胞中具有较低的相对适应性。这些发现表明，与蚊子传播相关的适应潜力因蚊子种类而异，并在脊椎动物中产生显著的适应成本。
The emergence of mosquito-borne RNA viruses, such as West Nile virus (WNV), is facilitated by genetically complex virus populations within hosts. Here, we determine whether WNV enzootic (Culex tarsalis, Cx. quinquefasciatus, and Cx. pipiens) and bridge vectors (Aedes aegypti) have differential impacts on viral mutational diversity and fitness. During systemic mosquito infection, WNV faced stochastic reductions in genetic diversity that rapidly was recovered during intra-tissue population expansions. Interestingly, this intrahost selection and diversification was mosquito-species dependent with Cx. tarsalis and Cx. quinquefasciatus exhibiting greater WNV divergence. However, recovered viral populations contained a preponderance of potentially deleterious mutations (i.e. high mutational load) and had lower relative fitness in avian cells compared to input virus. These findings demonstrate that the adaptive potential associated with mosquito transmission varies depending on the mosquito species and carries a significant fitness cost in vertebrates.