Specification of anterioposterior polarity in the mosquito, Chironomus

描述（由申请人提供）：早期胚胎的遗传电路为种群替换策略提供了目标，这在控制疾病媒介（如蚊子）方面具有重要的潜在应用。然而，蚊子的发育仍然知之甚少，因为目前对这一群体的研究主要集中在人类疾病媒介上，其中坚硬且色素浓重的蛋壳阻碍了功能发育研究。本研究的目的是阐明库蚊（Chironomus riparius, syn. C. thummi）胚胎前后极性（AP）的遗传机制。在Chironomus中，一系列实验扰动可导致完全或部分轴倒（镜像双腹或双头），这也可能自发发生。这些观察结果表明，早期蚊子胚胎的AP极性非常不稳定。此外，蚊子缺乏决定果蝇胚胎AP极性（昆虫发育的关键模型）的同源盒基因bicoid。我们已经建立了有效的研究河边Chironomus基因表达和功能（RNA干扰，mRNA注射）的方案，为在蚊子模型中测试候选基因阻止轴倒转的能力提供了工具。这一提议的具体目的是：(1)测试手蛾的同源基因，这些基因在其他昆虫的早期AP轴规范中有牵连，因为它们能够防止或诱导头部或腹部的镜像复制，以及(2)确定这些基因如何相互调节。这些实验将产生一个可能普遍适用于蚊子的Chironomus胚胎的AP轴规格模型。

DESCRIPTION (provided by applicant): Genetic circuitry of early embryos provides targets for population replacement strategies, which have important potential applications in the control of disease vectors such as mosquitoes. However, mosquito development remains poorly understood because current research in this group focuses on human disease vectors in which a tough and heavily pigmented eggshell hinders functional developmental studies. The research goal of this proposal is to elucidate the genetic mechanism that determines anterior-to-posterior (AP) polarity in embryos of the culicomorphan mosquito Chironomus riparius (syn. C. thummi). In Chironomus, a range of experimental perturbations can lead to complete or partial axis inversions (mirror image double abdomens or double heads), which may also occur spontaneously. These observations suggest that AP polarity in early mosquito embryos is very labile. Furthermore, mosquitoes lack the homeobox gene bicoid, which determines embryonic AP polarity in the fruit fly Drosophila (a key model for insect development). We have established efficient protocols for studying gene expression and function (RNA interference, mRNA injection) in Chironomus riparius, providing the tools for testing the ability of candidate genes to prevent axis inversions in a mosquito model. The specific aims of this proposal are to (1) to test Chironomus homologues of genes that have been implicated in early AP axis specification in other insects for their ability to prevent or induce mirror image duplications of the head or abdomen, and (2) to determine how these genes regulate each other. The experiments will result in a model for AP axis specification in Chironomus embryos that might be generally applicable for mosquitoes.