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DISSERTATION RESEARCH: Examining the role of reinforcement in driving genomic divergence between and within species in darters

论文研究：检验强化在驱动蛇鲈物种之间和物种内部基因组差异中的作用

基本信息

批准号：
1701676
负责人：
Rebecca Fuller
金额：
$ 2.06万
依托单位：
University of Illinois at Urbana-Champaign
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-05-01 至 2019-04-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1701676&HistoricalAwards=false
关键词：
DISSERTATION RESEARCH Examining role reinforcement

项目摘要

The study of how species arise has been revolutionized by new technologies that allow researchers to get large amounts of genomic information from different species quickly. This technology has been used to identify areas of the genome that differ between populations occurring in different environments, and which may be important in preventing closely-related species from forming hybrids. This project uses similar methods to compare populations that differ in whether they co-exist with a close relative with which they can hybridize. The project focuses on orangethroat darter fish. The project will identify genome areas associated with a preference to mate with one's own species, and test whether the same genetic changes happen in all closely-related species that coexist, or whether unique genetic changes occur each time. Data obtained from this study will provide critical insight into how differences in biological communities can drive species diversity. This project will provide valuable research opportunities and teaching materials for undergraduate students. Furthermore, the results of this research will be used to educate community members about the biology of local native fish species. Reinforcement plays a critical role in finalizing the process of speciation after secondary contact by increasing prezygotic isolation between taxa that produce unfit hybrids. As reinforcement directly selects for divergence in mating traits in sympatric populations, it can also incidentally lead to behavioral isolation among populations within species (i.e., cascade reinforcement). The objective of this project is to develop genomic tools to examine how reinforcement affects genome-wide divergence between and within species in two groups of darters (the orangethroat darter clade Ceasia and the rainbow darter Etheostoma caeruleum). Previous studies have provided strong behavioral evidence that reinforcement is driving behavioral isolation between sympatric Ceasia and E. caeruleum, and subsequently causing cascade reinforcement and behavioral isolation between species within Ceasia. This research will examine genomic divergence between species experiencing reinforcement, and investigate whether this divergence between species may incidentally be causing genomic divergence among populations within species (or among recently diverged species). Specifically, Next-Generation Sequencing will be utilized to (1) identify any differences in chromosomal structure between Ceasia and E. caeruleum that may be contributing to postzygotic isolation and facilitating reinforcement, (2) identify loci responsible for postzygotic isolation between Ceasia and E. caeruleum by genotyping hybrid and backcross individuals, and (3) conduct genome scans that compare genetic differentiation between multiple populations of Ceasia that are sympatric and allopatric with respect to E. caeruleum, in order to identify highly differentiated outlier loci between sympatric and allopatric populations that are likely associated with prezygotic isolation.

新技术使研究人员能够快速地从不同物种获得大量的基因组信息，从而彻底改变了物种如何产生的研究。这项技术已被用于识别不同环境中种群之间的基因组差异区域，这对于防止近亲物种形成杂交可能很重要。这个项目使用类似的方法来比较不同的种群，它们是否与一个近亲共存，它们可以杂交。该项目的重点是橙喉镖鱼。该项目将确定与偏好与自己的物种交配相关的基因组区域，并测试是否相同的基因变化发生在所有共存的近亲物种中，或者是否每次都发生独特的基因变化。从这项研究中获得的数据将为了解生物群落的差异如何驱动物种多样性提供关键的见解。本项目将为本科生提供宝贵的研究机会和教学材料。此外，这项研究的结果将用于教育社区成员有关本地鱼类的生物学。强化在二次接触后的物种形成过程中起着关键作用，它增加了产生不适合杂交种的类群之间的前合子分离。由于强化直接选择了同域种群中交配性状的分化，它也可能偶然导致物种内种群之间的行为隔离（即级联强化）。该项目的目标是开发基因组工具，以研究强化如何影响两组刺目动物（橙喉刺目动物分支Ceasia和彩虹刺目动物Etheostoma caeruum）之间和物种内部的全基因组差异。先前的研究已经提供了强有力的行为学证据，表明强化驱动同域天牛和紫叶天牛之间的行为隔离，并随后导致天牛内部物种之间的级联强化和行为隔离。本研究将研究经历强化的物种之间的基因组差异，并调查物种之间的这种差异是否可能偶然导致物种内种群（或最近分化的物种）之间的基因组差异。具体来说，下一代测序将用于(1)识别可能有助于合子后分离和促进强化的Ceasia和E. caeruum之间染色体结构的任何差异，(2)通过杂交和回交个体的基因分型确定Ceasia和E. caeruum之间负责合子后分离的位点。(3)进行基因组扫描，比较同域和异域分布的多种群间的遗传分化，以确定同域和异域分布种群之间可能与前合子分离相关的高度分化的异常位点。