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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迅速从不同物种获得大量基因组信息，从而使物种产生的研究发生了革命性的变化。这项技术已经被用来识别在不同环境中出现的不同种群之间的基因组区域，这些区域可能对防止密切相关的物种形成杂交很重要。该项目使用类似的方法来比较在是否与可以杂交的近亲共存方面存在差异的种群。该项目的重点是橙色飞镖鱼。该项目将确定与与自己物种交配的偏好相关的基因组区域，并测试是否所有共存的密切相关物种都会发生相同的基因变化，或者是否每次都会发生独特的基因变化。从这项研究中获得的数据将为生物群落的差异如何推动物种多样性提供关键的见解。该项目将为本科生提供宝贵的研究机会和教材。此外，这项研究的结果将用于教育社区成员有关当地本地鱼类物种的生物学知识。加强在二次接触后，通过增加产生不合适杂交的分类群之间的预合分离，在最终确定物种形成过程中发挥关键作用。当强化直接选择同域种群中交配特征的差异性时，它也可能附带地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飞镖(橙色飞镖支序Ceasia和彩虹飞镖Etheostoma caeruleum)物种之间和物种内的基因组范围的差异。以前的研究已经提供了强有力的行为证据，表明强化正在驱动共域Ceasia和E.caeruleum之间的行为隔离，从而导致Ceasia内物种之间的级联强化和行为隔离。这项研究将检查经历强化的物种之间的基因组差异，并调查这种物种之间的差异是否可能偶然地导致物种内(或最近分化的物种)种群之间的基因组差异。具体地说，下一代测序将被用于(1)鉴定Ceasia和E.caeruleum之间染色体结构上的任何可能有助于合子后分离和促进加固的差异，(2)通过对杂交和回交个体进行基因分型来确定负责Ceasia和E.caeruleum之间合子后分离的基因座，以及(3)进行基因组扫描，比较Ceasia和E.caeruleum的同地和异地种群之间的遗传分化，以便确定可能与合子前隔离相关的同地种群和异地种群之间的高度分化的离群点。