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

描述（由申请人提供）：埃及伊蚊是引起登革热和黄热病这两种具有全球公共卫生重要性的疾病的人类病毒的主要媒介。埃及伊蚊是一种非家养的物种，它们在充满水的人造容器中产下抗干燥的卵。在拟进行的研究中，我们将对细菌与Ae的相互作用进行全面的研究。蚊卵。该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。基于广泛的初步结果，我们的假设是，细菌相关的化学信号调节孵化，这与普遍接受的范式不同，即细菌快速生长导致的低溶解氧（DO）浓度刺激了鸡蛋孵化。我们的初步数据表明，最初从实验蚊子栖息地分离的14种细菌混合培养1天，在高和低DO条件下都能刺激卵孵化。然而，在所谓的刺激低DO条件下，鸡蛋在8天的培养液中浸没时无法孵化，这表明相同的细菌种类可以产生刺激和抑制线索，这取决于培养的年龄。在本研究中，我们将筛选从实验蚊子栖息地分离的14种细菌，研究其刺激和抑制卵孵化的生物活性。将选择具有高度刺激或抑制生物活性的细菌种类进行进一步研究。与细菌种类相关的化合物将通过生物测定引导的溶剂萃取和分离以及化学分析技术（包括高效液相色谱、气相色谱和质谱）来鉴定。假定的生物活性化合物的活性将在孵化生物测定中得到验证。一旦确定，控制孵化的线索可用于破坏蚊子卵的pharate幼虫的孵化，并为控制具有全球重要性的病毒载体提供创新工具。拟议的研究将提供一个更完整的理解的策略，Ae。埃及伊蚊卵在不断变化的环境条件下最大限度地生存。此外，该项目将为未来从胚胎到新生儿的生理事件的研究提供工具和试剂，包括基因表达模式和感觉生理学的研究。

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. PUBLIC HEALTH RELEVANCE: Aedes aegypti is vector for viruses that cause dengue and yellow fever, diseases of worldwide importance. Discovery of bacteria-associated factors that regulate hatching may lead to the development of novel, biologically-based tools for managing this important vector species.