Identification of bacteria-associated cues that regulate hatching of Aedes aegypt

描述(申请人提供)：埃及伊蚊是引起登革热和黄热病的人类病毒的主要媒介，这两种疾病对全球公共卫生具有重要意义。埃及伊蚊是一种家养附近的物种，它在装满水的人造容器中产卵，防止干燥。在拟议的研究中，我们将对细菌和Ae的相互作用进行全面的调查。埃及虫卵。拟议项目的主要目标是确定两组细菌产生的化学线索，一组刺激卵子孵化，另一组抑制卵子孵化。我们的假设基于广泛的初步结果，即细菌相关的化学提示调节孵化，这与普遍接受的范式背道而驰，即鸡蛋孵化是由细菌快速生长引起的低溶解氧(DO)浓度刺激的。我们的初步数据显示，最初从实验蚊子栖息地分离的14种细菌的混合培养1天后，在高DO和低DO条件下都能刺激卵孵化。然而，在被认为是刺激的低DO条件下，鸡蛋在8天前相同细菌种类的混合培养中无法孵化，这表明相同的细菌物种可以产生刺激和抑制的线索，这取决于培养的年龄。在拟议的研究中，我们将从实验蚊子栖息地中筛选出14种细菌，以研究其刺激和抑制卵孵化的生物活性。具有高度刺激或抑制生物活性的细菌种类将被选作进一步研究。与细菌物种相关的化学化合物将通过使用生物测定指导的溶剂提取和分级结合化学分析技术来鉴定，包括高效液相色谱和气相色谱以及质谱学。推测的生物活性化合物的活性将在鸡蛋孵化生物检测中得到验证。一旦确定，控制孵化的线索(S)可能被用来破坏蚊卵中法氏幼虫的孵化，并为控制具有全球重要性的病毒媒介提供创新的工具。拟议的研究将提供对Ae的策略的更完整的理解。埃及虫卵用于在不断变化的环境条件下最大限度地存活。此外，该项目还将为未来研究胚胎向新生儿过渡过程中的生理事件提供工具和试剂，包括基因表达模式和感觉生理学研究。

DESCRIPTION (provided by applicant): The mosquito Aedes aegypti is the primary vector of human viruses causing dengue and yellow fever, diseases of global public health importance. Aedes aegypti is a peri-domestic species that lays desiccation- resistant eggs in water-filled human-made containers. In the proposed research, we will conduct a comprehensive investigation of the interaction of bacteria and Ae. aegypti eggs. The main goal of the proposed project is to identify two groups of bacteria-produced chemical cues, one that stimulates and another that inhibits egg hatching. Our hypothesis, based on extensive preliminary results, that bacteria-associated chemical cues regulate hatching is a departure from the generally accepted paradigm that egg hatching is stimulated by low dissolved oxygen (DO) concentration resulting from rapid bacterial growth. Our preliminary data show that a 1-day old mixed culture of 14 bacterial species, originally isolated from an experimental mosquito habitat, stimulates egg hatching under both high and low DO conditions. However, under supposedly stimulatory low DO conditions, eggs fail to hatch when submerged in an 8-day old culture of the same mix of bacterial species, suggesting that the same bacteria species can produce stimulatory and inhibitory cues, depending on the age of culture. In the proposed research, we will screen 14 bacterial species isolates from experimental mosquito habitats for bioactivity in stimulating and inhibiting egg hatch. Bacterial species exhibiting highly stimulatory or inhibitory bioactivity will be selected for further research. Chemical compounds associated with bacterial species will be identified by using bioassay-guided solvent extraction and fractionation coupled with chemical analytical techniques, including high-performance liquid chromatography and gas chromatography, and mass spectrometry. The activity of putative bioactive compounds will be verified in egg hatching bioassays. Once identified, the cue(s) that control hatching may be used to disrupt hatching of the pharate larva from the mosquito egg and offer innovative tools for control of a virus vector of global importance. The proposed research will provide a more complete understanding of the strategies that Ae. aegypti eggs employ to maximize survival under changing environmental conditions. Moreover, the project will provide tools and reagents for future research on the physiological events during the transition from embryo to neonate, including gene expression patterns and studies of sensory physiology.