The molecular basis of electroreception across diverse organisms

我的研究计划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著的例子之一就是电感官的多个独立起源。这些能力包括被动探测微弱电场的能力，如海洋棘鳃和两栖动物所指出的那样。此外，美洲和非洲弱电鱼类通过产生和接收弱电场，独立进化出复杂的主动电接收，用于导航、目标定位和通信。尽管进行了数十年的行为和神经解剖学研究，但这些动物探测电场的分子机制仍不清楚。最近，我的工作建立了第一个理解电场检测是如何启动的机械立足点，表明电压门控钙通道和功能耦合钾通道的特定亚型对于在两个遥远的相关弹性肌支启动电接收至关重要，然而，在其他众多对不同电信号敏锐调谐的电感受性脊椎动物中，它们如何检测重要的电信号仍然没有答案。在电接收的多个独立起源中，是否存在共同的汇聚机制或具有不同物种共同选择的特定信号机制？现在，日新月异的技术使我能够以前所未有的精确度和专注度来问这些问题。这项探索奖助金有三个主要目标。这些研究将集中在鲟鱼--具有复杂的被动电感系统的原始软骨鱼类的成员--以及独立进化出高频弱电系统的美洲刀鱼(Gymnoformes)和非洲象总科(Mormyroidae)。这些研究将使用来自两性的物种，因为在活跃的电信号中存在性别二态。目标1是通过单细胞转录，确定在特定的电感受器中表达的一套基因，并将由一名理科学生完成。目的2是用膜片钳电生理学方法研究电感觉细胞在自体细胞和异种系统上的电反应特性，由两名博士生完成。目标3是通过电感觉细胞的药理学操作结合新颖的、定量的行为分析来确定电场检测的分子贡献，将由一名理科学生完成。总而言之，这些实验将在表型多样性的背景下，在遗传、细胞和行为维度上确定电接收的分子机制。

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.