The molecular basis of electroreception across diverse organisms

不同生物体电感受的分子基础

• 批准号: RGPIN-2021-03180
• 负责人: Leitch, Duncan
• 金额: $ 2.77万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=766126
• 关键词: molecular; basis; electroreception; across; diverse

The goals for my research program are to determine the mechanisms by which unique organisms detect low amplitude sensory signals to guide fundamental behaviours and to train HQP from diverse backgrounds. One of the most remarkable examples of convergent evolution among vertebrates is illustrated in the multiple independent origins of the electric senses. These include the capacity to passively detect weak electric fields as noted in marine elasmobranchs and amphibians. Furthermore, S. American and African weakly electric fishes independently evolved complex active electroreception for navigation, object localization, and communication via the generation and reception of weak electric fields. Despite decades of behavioural and neuroanatomical studies, the molecular mechanisms by which these animal detect electric fields have remained unknown. Recently, my work has established the first mechanistic foothold into understanding how the detection of electric fields is initiated, showing that specific isoforms of voltage-gated calciums channels and functionally coupled potassium channels are critical to initiating electroreception in two distantly related elasmobranchs Yet, among the multitude of other electroreceptive vertebrates, which are acutely tuned to diverse electric signals, how they detect important electric signals remains unanswered. Is there a common convergent mechanism or have diverse species co-opted specific signalling mechanisms among the multiple independent origins of electroreception? Rapidly changing technologies now allow me to ask these questions with an unparalleled level of precision and specificity. There are three primary objectives for this Discovery Grant. These research will focus on sturgeon - members of the primitive Chondrostei fish with an elaborate passive electrosensory system - and weakly electric S. American knife fish (Gymnotiformes) and African elephant fish (Mormyroidea) which independently evolved high frequency weakly electric systems. These studies will use species from both sexes as there is sexual dimorphism in active electric signals. Objective 1 is to determine the suite of genes expressed within specific electrosensory receptors, via single cell transcriptomics, and will be performed by one MSc student. Objective 2 is to determine the electrical response properties of electrosensory cells using patch clamp electrophysiology on native cells and heterologous systems and is to be performed by two PhD students. Objective 3 is to determine the molecular contributions to electric field detection through pharmacological manipulation of electrosensory cells combined with novel, quantitative behavioural analyses and will be performed by one MSc student. In sum, these experiments will identify molecular mechanisms of electroreception at genetic, cellular, and behavioural dimensions in the context of its phenotypic diversity.

我的研究项目的目标是确定独特的生物体检测低幅度感觉信号的机制，以指导基本行为并训练来自不同背景的 HQP。脊椎动物趋同进化最显着的例子之一是电感觉的多个独立起源。其中包括被动检测海洋软骨鱼和两栖动物中弱电场的能力。此外，南美洲和非洲的弱电鱼通过弱电场的产生和接收独立进化出复杂的主动电接收能力，用于导航、物体定位和通信。尽管进行了数十年的行为和神经解剖学研究，但这些动物检测电场的分子机制仍然未知。 最近，我的工作为理解电场检测是如何启动的建立了第一个机械立足点，表明电压门控钙通道和功能耦合钾通道的特定异构体对于启动两个远缘软骨鱼中的电接收至关重要。许多其他电感受脊椎动物能够敏锐地适应不同的电信号，但它们如何检测重要的电信号仍然没有答案。在电感受的多个独立起源之间是否存在共同的趋同机制或不同物种共同选择的特定信号传导机制？现在，快速变化的技术使我能够以无与伦比的精确度和特异性提出这些问题。该发现补助金有三个主要目标。这些研究将集中于鲟鱼（具有复杂的被动电感应系统的原始软骨鱼的成员）以及独立进化出高频弱电系统的弱电南美刀鱼（Gymnotiformes）和非洲象鱼（Mormyroidea）。这些研究将使用两性物种，因为主动电信号存在性别二态性。目标 1 是通过单细胞转录组学确定特定电感觉受体内表达的一组基因，并将由一名理学硕士学生执行。目标 2 是利用膜片钳电生理学对天然细胞和异源系统确定电传感细胞的电响应特性，由两名博士生完成。目标 3 是通过电传感细胞的药理学操作结合新颖的定量行为分析来确定分子对电场检测的贡献，并将由一名理学硕士学生执行。总之，这些实验将在表型多样性的背景下确定遗传、细胞和行为维度上电感受的分子机制。