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.

我的研究计划的目标是确定独特的生物体检测低振幅感觉信号的机制，以指导基本行为，并从不同的背景中训练HQP。脊椎动物趋同进化的一个最显著的例子是电感觉的多个独立起源。这些包括被动检测弱电场的能力，如海洋板鳃类和两栖动物所指出的。此外，S.美洲和非洲的弱电鱼类独立地进化出复杂的主动电感受，用于导航、物体定位和通过产生和接收弱电场进行通信。尽管数十年的行为和神经解剖学研究，这些动物检测电场的分子机制仍然未知。 最近，我的工作已经建立了第一个机械立足点，以了解电场的检测是如何启动的，表明电压门控钙通道和功能耦合钾通道的特定亚型对启动两个远亲板鳃类的电感受至关重要。然而，在众多其他电感受性脊椎动物中，它们对不同的电信号进行了敏锐的调整，它们是如何探测到重要的电信号的仍然没有答案。在电感受的多个独立起源中，是否存在共同的会聚机制或不同物种共同选择特定的信号传导机制？日新月异的技术使我能够以前所未有的精确度和特异性提出这些问题。本次发现补助金有三个主要目标。这些研究将集中在鲟鱼-原始软骨鱼类的成员，具有复杂的被动电感觉系统-和弱电S。美洲刀鱼（裸背鱼形目）和非洲象鱼（象鼻鱼总科），它们独立地进化出高频弱电系统。这些研究将使用两性物种，因为活性电信号中存在两性异形。目标1是通过单细胞转录组学来确定特定电感觉受体内表达的基因组，并将由一名硕士学生进行。目的2是确定电感觉细胞的电响应特性，使用膜片钳电生理学对天然细胞和异源系统，将由两名博士生进行。目标3是确定分子电场检测的贡献，通过药理学操作的电感觉细胞结合新的，定量的行为分析，并将由一个硕士生进行。总之，这些实验将确定在遗传，细胞和行为方面的表型多样性的背景下，电感受的分子机制。