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.

关于物种如何出现的研究已被新技术彻底改变，这些技术使研究人员可以迅速从不同物种中获取大量基因组信息。该技术已用于确定基因组的区域，这些区域在不同环境中发生的种群之间有所不同，这对于防止与密切相关的物种形成杂种可能很重要。该项目使用类似的方法来比较种群在与可以杂交的近亲共存的种群中有所不同。该项目着重于甲状腺甲状腺darter鱼。该项目将确定与偏爱与自己的物种相吻合相关的基因组区域，并测试在共存的所有密切相关物种中是否发生相同的遗传变化，或者是否每次都会发生独特的遗传变化。从这项研究中获得的数据将对生物群落的差异如何推动物种多样性提供重要的见解。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鱼类物种的生物学。通过增加产生不合适杂种的分类单元之间的二整体隔离，增强在最终确定二次接触后的物种形成过程中起着关键作用。由于强化直接选择了同胞种群中交配性状的差异，因此它也可能导致物种内种群之间的行为隔离（即级联增强）。该项目的目的是开发基因组工具，以研究强化如何影响两组DARTERS（Orangethroat Darter darter clade Ceasia和Rainbow Darter Dearter etheostoma caeruleum）的种类之间和内部基因组之间的差异。先前的研究提供了强有力的行为证据，表明加强是在同胞Ceasia和Caeruleum之间推动行为隔离，并随后引起Ceasia内部物种之间的级联加固和行为隔离。这项研究将检查经历增强物种之间的基因组差异，并研究物种之间的这种差异是否可能偶然地导致物种种群（或最近分歧物种）之间的基因组差异。具体而言，下一代测序将用于（1）确定Ceasia和Ceeruleum之间的染色体结构的任何差异，可能导致后腹部隔离并促进加固的基因座，这些基因座负责确定在Ceasia和E. ceerulem之间通过Genotim and Backans and Backers和Backcrss crance and Backs Cross和Backcrss crancy和Backcrss crance and Backs Cross和Backcrss and crosss and Cranse and Backs Cross and Cranding（3在相对于囊大肠杆菌的同胞和同种异体的多个ceasia种群之间，以识别可能与同进隔离相关的同胞和同种异体种群之间高度分化的离群基因座。