Molecular regulation of diapause in Culex pipiens

描述（由申请人提供）：本提案主要研究北方库蚊（库蚊）滞育（休眠）的分子基础。在初秋，这个物种的成年雌性寻找受保护的地方，整个冬天都呆在那里，处于一种繁殖不活跃的状态，称为滞育。虽然关于滞育的生理和环境控制的许多方面都是众所周知的，但关于这种滞育或任何其他媒介物种的滞育的分子基础的信息很少。获得这些信息不仅对了解蚊子季节周期的调节至关重要，而且对了解蚊子传播的病原体的季节性也至关重要。对于Cx。越冬的雌性库蚊似乎携带西尼罗病毒，从而成为第二年春天将病毒重新引入鸟类种群的机制。

DESCRIPTION (provided by applicant): This proposal focuses on the molecular basis for diapause (dormancy) in the northern house mosquito, Culex pipiens. In the early autumn adult females of this species seek protected sites and remain there throughout the winter months in a reproductively inactive state know as diapause. Although many aspects of the physiology and environmental control of diapause are well known, there is little information concerning the molecular basis for this diapause or the diapause of any other vector species. Obtaining such information is critical not only for understanding regulation of seasonal cycles of mosquitoes, but also for understanding the seasonality of pathogens the mosquito transmit. In the case of Cx. pipiens the overwintering females appear to harbor West Nile virus, and thus serve as the mechanism for reintroducing the virus into bird populations the following spring. Our initial studies using suppressive subtractive hybridization (SSH) have identified four categories of genes that are upregulated in early diapause. These include genes involved in the diapause-associated switch from blood feeding to sugar feeding, the arrest of development, cold-hardening, and responding to juvenile hormone. Similar SSH experiments will examine mid and late stages of diapause. Clones isolated with this technique will be further characterized by full-length sequencing, by evaluating expression patterns throughout diapause using northern blotting and real-time PCR, by examining tissue-specific expression patterns, and by evaluating gene function using RNA interference. We also plan to use SSH to search for genes associated with the programming phase of diapause (early pupal stage). Such genes are likely to be involved in the decision to either enter or avert diapause. At the conclusion of this study we expect to have identified major gene pathways involved in the regulation of diapause in Cx. pipiens, thus allowing us to begin the construction of a regulatory hierarchy for diapause in this species. We anticipate that these results will suggest vulnerable targets for disrupting diapause and may provide clues for how viral replication is halted during the winter months.