"Sensing, transfer and regulation of ions and gases: Studies in a model organism, the zebrafish (Danio rerio)"

“离子和气体的传感、传输和调节：对模式生物斑马鱼 (Danio rerio) 的研究”

• 批准号: 38050-2012
• 负责人: Perry, Steve
• 金额: $ 8.01万
• 依托单位: University of Ottawa
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=568807
• 关键词: Sensing; transfer; regulation; ions; gases

This research proposal focuses on two key aspects of fundamental importance to the adaptation of fish to fluctuating environments; regulating the ionic composition of their body fluids and the sensing and transfer of the respiratory gases O2 and CO2. While we have learned much about the mechanisms of ion movement across epithelial such as gills and skin, virtually nothing is know about the metabolic cost of ion regulation - what does it cost (in energy) to move ions across a cell? I will examine this question using ionic uptake by the epidermal ion-transporting cells of zebrafish larvae as a model system. My trainees and I will use state-of-the-art scanning polarographic- and canning ion-selective electrode techniques to simultaneously measure ion and O2 fluxes into ionocytes to provide the first direct estimates of the metabolic cost of ion regulation. Additional research in the field of ion regulation will concentrate on establishing the regulatory mechanisms allowing fish to adjust ion uptake rates during environmental challenges such as lowered ambient O2 (hypoxia) and changing salinity. The basic mechanisms underlying the transfer of O2 and CO2 across biological membranes are being re-evaluated with the discovery of gas channels. The proposed research will exploit the power of "gene knockdown" in zebrafish to examine the possibility that CO2 moves through aquaporins, traditionally thought to function as water channels and that O2 moves though either aquaporins or Rh proteins (ammonia channels). The rate of transfer of O2 and CO2 across respiratory surfaces is governed by their sensing by specialized chemoreceptors. Little is known, however, about the mechanisms of chemoreception in fish. This proposal will focus on the role of carbonic anhydrase in CO2 chemoreception and hydrogen sulphide in O2 chemoreception.

这项研究计划侧重于鱼类适应波动环境的两个至关重要的关键方面;调节体液的离子组成以及呼吸气体O2和CO2的传感和传输。虽然我们已经了解了很多关于离子在上皮细胞（如鳃和皮肤）中运动的机制，但实际上对离子调节的代谢成本一无所知--离子在细胞中运动的成本（能量）是多少？ 我将研究这个问题，使用离子吸收的表皮离子转运细胞的斑马鱼幼虫作为一个模型系统。我和我的学员将使用最先进的扫描极谱和罐装离子选择性电极技术，同时测量离子和O2流入离子细胞，以提供离子调节代谢成本的第一个直接估计。 离子调节领域的其他研究将集中在建立调节机制，使鱼类能够在环境挑战期间调整离子吸收率，例如降低环境O2（缺氧）和改变盐度。 随着气体通道的发现，O2和CO2跨生物膜转移的基本机制正在重新评估。这项拟议中的研究将利用斑马鱼中“基因敲低”的力量来研究CO2通过水通道蛋白移动的可能性，传统上认为水通道蛋白起水通道的作用，而O2通过水通道蛋白或Rh蛋白（氨通道）移动。 O2和CO2通过呼吸道表面的传输速率由专门的化学感受器对其的感知控制。然而，对鱼类化学感受的机制知之甚少。 这项建议将集中在碳酸酐酶在CO2化学感受和硫化氢在O2化学感受中的作用。