在对“黄热病”蚊子（埃及伊蚊）和蚊子传播的辛德毕斯病毒的一系列实验中，Kevin Myles及其同事发现了导致人类急性疾病的病毒如何无法显著影响其宿主蚊子的健康。这组科学家发现尽管蚊子传播的病毒以类似的方式感染人类和蚊子，蚊子的低水平的“沉默”感染对于让该病毒在环境中传播是至关重要的。
蚊子传播的辛德毕斯病毒病毒的遗传物质是RNA，而且这种病毒的宿主可以通过把它的RNA切成小片从而对抗感染。这些小分子干扰RNA（siRNAs）然后可以指导宿主的免疫系统进一步限制病毒的复制。这组科学家发现埃及伊蚊的siRNAs的产生对于这种昆虫感染辛德毕斯病毒之后的生存至关重要。他们用一种重组辛德毕斯病毒感染了蚊子，这种病毒拥有额外的基因用于抑制siRNAs的形成，结果他们发现实验蚊子迅速死亡，而感染了野病毒的蚊子的寿命正常。这组科学家说，SiRNAs为宿主和病原体提供了一个进化收益，帮助保持蚊子存活且能够传播这种病毒。（生物谷Bioon.com）
生物谷推荐原始出处：
PNAS published online before print December 1, 2008, doi:10.1073/pnas.0803408105
Alphavirus-derived small RNAs modulate pathogenesis in disease vector mosquitoes
Kevin M. Myles, Michael R. Wiley, Elaine M. Morazzani, and Zach N. Adelman
Mosquito-borne viruses cause significant levels of morbidity and mortality in humans and domesticated animals. Maintenance of mosquito-borne viruses in nature requires a biological transmission cycle that involves alternating virus replication in a susceptible vertebrate and mosquito host. Although the vertebrate infection is acute and often associated with disease, continual transmission of these viruses in nature depends on the establishment of a persistent, nonpathogenic infection in the mosquito vector. An antiviral RNAi response has been shown to limit the replication of RNA viruses in flies. However, the importance of the RNAi pathway as an antiviral defense in mammals is unclear. Differences in the immune responses of mammals and mosquitoes may explain why these viruses are not generally associated with pathology in the invertebrate host. We identified virus-derived small interfering RNAs (viRNAs), 21 nt in length, in Aedes aegypti infected with the mosquito-borne virus, Sindbis (SINV). viRNAs had an asymmetric distribution that spanned the length of the SINV genome. To determine the role of viRNAs in controlling pathogenic potential, mosquitoes were infected with recombinant alphaviruses expressing suppressors of RNA silencing. Decreased survival was observed in mosquitoes in which the accumulation of viRNAs was suppressed. These results suggest that an exogenous siRNA pathway is essential to the survival of mosquitoes infected with alphaviruses and, thus, the maintenance of these viruses in nature.