蚊虫生殖过程中糖代谢调控机制的研究

Repeatedly feeding on vertebrate blood is essential for anautogenous mosquitoes to finish their gonadotrophic cycles. This unique physiological feature makes female mosquitoes become vectors of multiple devastating human diseases. Juvenile hormone and 20-hydroxyecdysone can alternately regulate the reproductive cycle of female mosquitoes, which play a crucial role in the reproductive cycle of mosquitoes. However, the molecular mechanism of carbohydrate metabolism (CM) regulated by hormone is still unclear. Our previous studies indicate that the changes of their titers have an impact on the levels of CM, which is the main source of energy in the reproductive process of mosquitoes. Thus, it is very important to understand the detailed mechanisms governing CM during mosquito reproduction. First of all, we can obtain the dynamic expression levels of related transcription factors (TFs) in Aedes aegypti using high-throughput sequencing and bioinformatics analysis. And then, in order to select the regulatory factors of CM, we should confirm the influence of TFs in regulating CM through RNA interference (RNAi) combined with gas chromatography-mass spectrometry (GC-MS) and other molecular biology methods. At last, we need to figure out the interplay between hormone and TFs in regulating CM of A. aegypti. The knowledge acquired from the project will enrich the regulatory mechanism of mosquito reproduction and be extremely valuable to provide the potential molecular targets as well as theoretical basis of drug design for mosquito control.

蚊虫是非自殖性昆虫，需要吸食脊椎动物的血才能完成其生殖过程，这一特殊的生理习性使得埃及伊蚊成为许多人类重要病原的传播媒介。保幼激素和蜕皮激素可以交替调控蚊虫生殖周期，在蚊虫生殖发育过程中起着重要作用，但是激素对蚊虫代谢调控的分子机制尚不清楚。我们先前研究结果表明，激素滴度变化可以影响蚊虫糖代谢水平，糖代谢是蚊虫生殖过程中所需能量的主要来源，因此，详细解析蚊虫生殖过程中糖代谢调控的分子机制至关重要。首先利用高通量测序和生物信息学方法，分析埃及伊蚊生殖过程中相关转录因子的表达情况；然后利用RNA干扰、气相色谱-质谱联用及其它的分子生物学实验方法研究转录因子对糖代谢的影响，筛选出调控糖代谢的转录因子；最后阐明激素与该转录因子在蚊虫糖代谢调控中的级联作用关系。通过本项目的研究，不仅可以丰富蚊虫生殖调控的分子机制，而且能够为控制蚊虫的药物设计提供潜在的分子靶标及理论依据。

蚊虫是非自殖性昆虫，需要吸食脊椎动物的血才能完成其产卵过程，这一特殊的生理特性使得蚊虫成为许多重要人类病原的传播媒介。因此，揭示蚊虫生殖调控的分子机制成为阻断蚊媒病原传播的有效措施。蚊虫生殖是一个高度耗能的过程，伴随着能量的贮存与消耗。先前研究已经表明，调控蚊虫生殖的两个重要激素：保幼激素JH和蜕皮激素20E的滴度变化直接影响蚊虫体内糖代谢水平。然而激素对糖代谢的调控机制仍然不是很清楚。本研究以埃及伊蚊为研究对象，揭示了蚊虫生殖过程中糖代谢调控的分子机制。我们采用高通量测序和生物信息学方法对蚊虫不同发育时间点的转录组和蛋白质组数据进行了分析，结合蚊虫体内激素滴度变化趋势，发现转录因子ERRα与蚊虫生殖和糖代谢变化密切相关。随后利用双荧光素酶报告实验和凝胶阻滞实验证实，蚊虫吸血后，20E通过与其胞内受体EcR/USP形成激素受体复合物直接激活ERRα的表达，被激活的ERRα通过直接结合到糖分解代谢酶基因（例如HEX和TPS）的启动子区而进一步激活糖分解代谢过程，从而为蚊虫卵的发育和成熟提供能量。除此之外，我们还发现在JH和20E的协同调控下，转录因子E93成为蚊虫不同生殖周期之间转变的关键调控因子。同时，在雌蚊糖代谢研究的启发下，我们发现雄蚊在羽化后的发育过程中同样存在糖代谢的动态变化。该研究不仅推动了我们在蚊虫生殖学研究领域的认知，而且为新型防控手段阻断病原传播提供了理论基础。