Biochemistry of Chorion Hardening in Mosquitoes

描述：洪水蚊子，如埃及伊蚊、卵蚊 在水边的基板，和鸡蛋孵化后，只有被淹没 在充足的降雨之后。因此，抗干燥和 其他不利的环境条件是至关重要的生存这些 鸡蛋产卵后，绒毛膜在潮湿的环境中3-4小时变硬。 环境，和一个硬化的绒毛膜提供保护的发展 绒毛膜内的胚胎。PI证明了两个相互关联的 生化事件，酚氧化酶/多巴脱羧酶催化的绒毛膜 涉及黑化和过氧化物酶介导的绒毛膜蛋白交联 在A.埃及人。结果表明 绒毛膜过氧化物酶催化的绒毛膜蛋白交联是至关重要的步骤， 该过氧化物酶与其它描述的过氧化物酶显著不同， 它的进化方式可能反映了它在绒毛膜中的生物学作用 形成和硬化。该补助金的目标是实现一个全面的 了解绒毛膜过氧化物酶和酚氧化酶与 绒毛膜生物合成和硬化。具体目标包括：（1）隔离 绒毛膜过氧化物酶cDNA和时间和空间转录的评估， 2)用于酶表征和抗体的重组蛋白的生产 生产，3）绒毛膜过氧化物酶的生物化学表征，和4） 绒毛膜酚氧化酶的生化和分子特性。 蚊媒病原体继续对人类健康产生重大影响 以及抗药性寄生虫的发展， 对杀虫剂有抗药性的蚊子媒介迫切需要新的蚊子或 制定寄生虫防治战略。破坏所需的 生理生化过程是必要的正常发展 蚊子是控制蚊子传播疾病的一种方法。更好的 了解蚊子绒毛膜形成的生理学和生物化学 对于彻底了解这一地区的生殖过程至关重要。 重要的疾病媒介。卵的存活时间延长 在恶劣环境条件下的时间，如洪水所需 蚊子，主要依赖于绒毛膜的生化过程， 生物合成和硬化。据估计， 卵绒毛膜发育所需的生化途径及其调控 可能会提供新的方法来控制蚊子， 破坏所需的生殖过程。

DESCRIPTION: Floodwater mosquitoes, such as Aedes aegypti, oviposit on substrates at the edge of water, and the eggs hatch only after being flooded following adequate rainfall. Therefore, the ability to resist desiccation and other adverse environmental conditions is critical for the survival of these eggs. After oviposition, the chorion hardens in 3-4 hours in a moist environment, and a hardened chorion provides protection for the developing embryo within the chorion. The PI has demonstrated that two interrelated biochemical events, Phenoloxidase/dopa decarboxylase- catalyzed chorion melanization and peroxidase-mediated chorion protein crosslinking are involved in the overall chorion hardening in A. aegypti. Results indicate that the chorion peroxidase-catelyzed chorion protein crosslinking is a vital step and that the peroxidase is significantly different from other described peroxidases and has evolved in a manner that likely reflects its biological role in chorion formation and hardening. The objectives of this grant are to achieve a full understanding of the chorion peroxidase and phenoloxidase in relation to chorion biosynthesis and hardening. Specific aims include 1) isolation of the chorion peroxidase cDNA and assessment of temporal and spatial transcription, 2) production of recombinant protein for enzyme characterization and antibody production, 3) biochemical characterization of chorion peroxidase, and 4) the biochemical and molecular characterization of chorion phenoloxidase. Mosquito-borne pathogens continue to have a major impact on human health throughout the world, and the development of drug resistant parasites and insecticide resistant mosquito vectors urgently demands that new mosquito or parasite control strategies be developed. Disruption of the required physio-biochemical processes that are necessary for the normal development of mosquitoes is one approach for the control of mosquito-borne disease. A better knowledge of the physiology and biochemistry of chorion formation in mosquitoes is critical to a thorough understanding of reproductive processes in this important group of disease vectors. Survival of eggs for extended periods of time in adverse-environmental conditions, as is required for floodwater mosquitoes, is critically dependent on the biochemical process of chorion biosynthesis and hardening. It is anticipated that an elucidation of the biochemical pathways and their regulation required for egg chorion development might provide new approaches for the control of mosquitoes through the disruption of required reproductive processes.