Ion transport and motility in larval mosquito stomach

描述（由申请方提供）：蚊子幼虫最突出的器官是胃，它构成胃肠道的主要部分。该器官对于离子、体积和酸/碱稳态具有突出的重要性。前胃主动分泌碱当量，产生极高pH的隔室，这对于消化很重要，但也对于对生物控制剂如苏云金芽孢杆菌内毒素的敏感性很重要。在后胃中，通过碱当量的恢复，pH值几乎恢复到中性值。最有可能的是，该循环涉及酸/碱当量以及钠离子和氯离子的高周转。离子运输的过程，他们的调节和他们的协调与幼虫蚊子胃中的消化作用知之甚少。该项目旨在了解两种蚊子的这些过程：黄热病蚊子（埃及伊蚊）和撒哈拉以南非洲的疟疾蚊子冈比亚按蚊。具体来说，我们将确定：1。前胃碱化的离子转运机制。 2.后胃再酸化的离子转运机制。3.前胃和后胃离子转运的调节机制。4.胃前后部离子转运与胃排空的协调机制。这些研究将主要使用五种不同的方法进行：1.使用传统的经上皮技术和微电极2.）使用灌注液中的pH指示剂和/或pH敏感微电极分析离体胃段的腔pH变化3）。涉及的转运蛋白和调节单位/系统的组织化学和免疫组织化学定位4.）转运蛋白活性的生化测定及其通过激素/非激素因子的调节5.）应用电生理技术和图像分析技术分析脑缺血及其调控。该项目的结果将为蚊子控制剂的开发提供有关具体目标的信息。

DESCRIPTION (provided by applicant): The most prominent organ of larval mosquitoes is the stomach, which makes up the major part of the gastrointestinal tract. This organ is of prominent importance for ionic, volume and acid/base homeostasis. The anterior stomach actively secretes alkali equivalents, generating a compartment of extremely high pH which is of importance for digestion, but also for the susceptibility to biological control agents such as Bacillus thuringienis endotoxin. In the posterior stomach the pH returns to almost neutral values by recovery of alkali equivalents. Most likely, this cycle involves a high turnover of acid/base equivalents as well as of sodium and chloride ions. The processes of ion transport, their regulation and their coordination with peristalsis in the stomach of larval mosquitoes are poorly understood. The project is directed at understanding these processes in two mosquito species: the yellow fever mosquito (Aedes aegypti) and the malaria mosquito of subsaharan Africa Anopheles gambiae. Specifically we will determine: 1. the ion transport mechanisms involved in alkalization of the anterior stomach. 2. the ion transport mechanisms involved in reacidification of the posterior stomach. 3. the mechanisms of regulation of ion transport in the anterior and posterior stomach. 4. the mechanisms of coordination of ion transport with peristalsis in the anterior and posterior stomach. The studies will be carried out, using mainly five different methodological approaches: 1.) Electrophysiological characterization of ion transport across isolated stomach segments and its regulation, using conventional transepithelial techniques and microelectrodes 2.) Analyses of luminal pH changes with isolated stomach segments, using pH indicators and/or pH sensitive microelectrodes in the perfusate 3.) Histochemical and immunhistochemical localization of involved transporters and regulative units/systems 4.) Biochemical determination of transporter activities and their regulation by hormonal/non-hormonal factors 5.) Analyses of peristalsis and its regulation with electrophysiological techniques and image analyses. The results of this project will provide information about specific targets for the development of mosquito control agents.