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Collaborative Research: Analysis of rapidly evolving potassium channels in electric fish

合作研究：电鱼快速进化的钾通道分析

基本信息

批准号：
1856695
负责人：
Harold Zakon
金额：
$ 62万
依托单位：
University of Texas at Austin
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2019
资助国家：
美国
起止时间：
2019-09-15 至 2024-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1856695&HistoricalAwards=false
关键词：
Collaborative Research Analysis rapidly evolving

项目摘要

The purpose of this project is to understand how genetic changes contribute to the evolution of new animal signaling behaviors. The investigators of this collaborative project will study this question in weakly electric fishes from Africa, known as mormyrids. The team has previously discovered a protein, encoded by the gene kcna7a that has undergone intense natural selection mormyrids, which allows mormyrids to produce extremely short electric signals called an electric organ discharge (EOD). Despite the strong selection on mormyrids for brief EOD pulses, the evolution of pulse duration varies dramatically across the more than 200 species of mormyrids, and long duration EOD pulses have evolved at least three times from short-duration EOD pulse ancestors. The underlying hypothesis of this project is that the long-duration EODs are the result of selection acting on amino acid substitutions in the kcna7a gene. In this project, the investigators will test this hypothesis by examining the biophysical properties of kcna7a in species that secondarily evolved long duration EODs, and conduct field-based behavioral studies to determine the selective factors that lead to the evolution of long duration EODs. This project will enhance infrastructure for research by adding data products, refined functionality, and tools to the broadly utilized EFISH Genomics Web Portal, promote teaching and learning by ongoing mentorship of undergraduates, graduate students and postdoctoral associates associated and broaden participation by continuing the productive relationship with a network of institutional partners to recruit talented personnel from underrepresented groups, working with Huston-Tillotson University, a HBCU in Austin, TX.A major goal of 21st century biology is to understand how changes at the molecular level result in phenotypic changes at the organismal level. Despite the growing progress in unraveling the "molecular basis of phenotype" in a wide variety of taxa, it is important to maintain the view that forces at higher levels of biological organization shape phenotypes from the "top down". In many systems, these factors are well known, but their precise connection to identified genetic variants is still poorly understood. In electric fish, the selective forces that influence electric phenotype are known, the loci that produce them are identified, the specific nucleotides within these loci that affect function are characterized, and these loci are known to be targets of selection on macroevolutionary scales. In Specific Aim 1, this project will: determine the biophysical basis of secondary evolution of long EOD pulses by sequencing kcna7a in species that secondarily evolved long duration EODs and their congeners with short duration EODs, measuring their biophysical properties, examining the role of specific sites using site-directed mutagenesis, and determining whether secondarily derived long-duration EODs evolved once or multiple times in parallel. In Specific Aim 2, the investigators will determine whether species that produce long duration EODs have long-duration APs and, and whether properties of kcna7a currents are sufficient to lengthen them, using a combination of electrophysiology and computational modeling. In Specific Aim 3, the investigators will determine the selective factors that lead to the evolution of long duration EODs using by performing field studies in Gabon West-Central Africa. A investigators will continue their efforts to broaden participation of underrepresented groups in partnership with an HBCU.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该项目的目的是了解基因变化如何促进新的动物信号行为的进化。该合作项目的研究人员将在来自非洲的弱电鱼（称为斑尾鱼）中研究这个问题。研究小组此前发现了一种由基因kcna7a编码的蛋白质，该蛋白质经历了斑鸠强烈的自然选择，使斑鸠能够产生极短的电信号，称为器官电放电（EOD）。尽管斑鸠鱼对短时 EOD 脉冲有强烈的选择，但在 200 多种斑鸠鱼中，脉冲持续时间的进化差异很大，并且长持续时间 EOD 脉冲从短持续时间 EOD 脉冲祖先进化了至少三倍。该项目的基本假设是，长期 EOD 是作用于 kcna7a 基因中氨基酸取代的选择的结果。在该项目中，研究人员将通过检查二次进化出长持续时间EOD的物种中kcna7a的生物物理特性来检验这一假设，并进行基于现场的行为研究，以确定导致长持续时间EOD进化的选择性因素。该项目将通过向广泛使用的 EFISH 基因组学门户网站添加数据产品、完善的功能和工具来增强研究基础设施，通过对相关本科生、研究生和博士后的持续指导来促进教学和学习，并通过继续与机构合作伙伴网络保持富有成效的关系，与 Huston-Tillotson 合作，从代表性不足的群体中招募人才，从而扩大参与范围德克萨斯州奥斯汀市的 HBCU 大学。21 世纪生物学的一个主要目标是了解分子水平的变化如何导致有机体水平的表型变化。尽管在揭示多种类群的“表型的分子基础”方面取得了不断的进展，但重要的是要坚持这样的观点，即生物组织高层的力量从“自上而下”塑造表型。在许多系统中，这些因素是众所周知的，但它们与已识别的遗传变异的精确联系仍然知之甚少。在电鱼中，影响电表型的选择力是已知的，产生它们的基因座被识别，这些基因座内影响功能的特定核苷酸被表征，并且已知这些基因座是宏观进化尺度上的选择目标。在具体目标 1 中，该项目将：通过对二次进化长持续时间 EOD 及其短持续时间 EOD 的同源物种中的 kcna7a 进行测序，确定长 EOD 脉冲二次进化的生物物理基础，测量其生物物理特性，使用定点诱变检查特定位点的作用，并确定二次衍生的长持续时间 EOD 是否并行进化一次或多次。在具体目标 2 中，研究人员将结合电生理学和计算模型，确定产生长持续时间 EOD 的物种是否具有长持续时间 AP，以及 kcna7a 电流的特性是否足以延长它们。在具体目标 3 中，研究人员将通过在加蓬中西部非洲进行实地研究来确定导致长期 EOD 演变的选择性因素。调查人员将继续努力与 HBCU 合作，扩大代表性不足群体的参与。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优点和更广泛的影响审查标准进行评估，被认为值得支持。