DISSERTATION RESEARCH: Delineation of populations, species, and genomic adaptations across a widely distributed venomous snake species complex

论文研究：描述广泛分布的毒蛇物种复合体的种群、物种和基因组适应

基本信息

批准号：
1501886
负责人：
Todd Castoe
金额：
$ 1.97万
依托单位：
University of Texas at Arlington
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2015
资助国家：
美国
起止时间：
2015-06-01 至 2017-05-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1501886&HistoricalAwards=false
关键词：
DISSERTATION RESEARCH Delineation populations species

项目摘要

Characterizing the diversity and relatedness of life is an important goal of evolutionary biology, and our understanding of this diversity provides a framework to address important questions. Many of these questions relate to adaptations that are evolved over time to better suit organisms to their environment. In particular, it is little understood whether the same evolutionary forces and processes may act in a similar manner to produce locally adapted traits in closely related lineages. Are certain genes or genomic regions repeatedly targeted by natural selection across species that occupy drastically different habitats and climates? This research aims to address these questions using a unique system of North American rattlesnakes, the Crotalus viridis species complex. Snakes of this group are highly diverse in their coloration, size, and venom composition, and thrive in diverse ecoregions. This research program will generate a robust understanding of the evolutionary relationships among members of this group, which will also provide a contextual framework for testing hypotheses of how natural selection has driven their diversification. This research program will then use information collected from throughout the genomes of these lineages to look for evidence of genes and sets of genes that are common targets of selection for local adaptation.Understanding the systematics of species complexes can be challenging, but new and robust analytical approaches, together with large genome-scale datasets from next-generation sequencing technology are making this challenge increasingly manageable. Despite the difficulties inherent in studying species complexes, these systems are ideal for linking our understanding of their biodiversity with the genomic processes that have shaped their evolution and diversity. This project seeks to make these connections using a comparative phylogenetic system, the Crotalus viridis species complex. The research program will generate the first robust species tree for the complex, which has historically been a problematic group for systematists, using genome-wide single nucleotide polymorphism data. This phylogenetic framework will then be used as a comparative platform for analyses of genes and genomic regions under selection within and among lineages. This research will interrogate the genomes of multiple populations and species to address the question of whether selection regimes target common loci across such a species complex, or if genes and functional categories of genes are idiosyncratically targeted by lineage. Collectively, this research will characterize the evolutionary history of a diverse and medically relevant venomous snake group and will add considerably to our knowledge of the roles that adaptation and convergent evolution play in the generation of biodiversity at multiple scales.

表征生活的多样性和相关性是进化生物学的重要目标，我们对这种多样性的理解为解决重要问题提供了框架。这些问题中有许多与随着时间的流逝而演变的适应性有关，以更好地适应其环境。特别是，几乎没有理解相同的进化力和过程是否可以以类似的方式作用以在紧密相关的谱系中产生局部适应的特征。某些基因或基因组区域是否反复以自然选择为目标，这些物种占据了截然不同的栖息地和气候？这项研究旨在使用北美响尾蛇（Crotalus viridis物种综合体）的独特系统来解决这些问题。该群的蛇的颜色，大小和毒液成分高度多样，并且在各种生态区域中壮成长。该研究计划将对该小组成员之间的进化关系产生强烈的理解，该研究还将提供一个上下文框架，以测试自然选择如何驱动其多样化的假设。然后，该研究计划将使用从这些谱系的整个基因组中收集的信息来寻找基因和基因集的证据，这些基因和基因集成为局部适应性选择的常见目标。理解物种复合物的系统学可能是具有挑战性的，但是新的和强大的分析方法，以及从下一代序列中越来越多地挑战了越来越多的基因组尺度的数据集，使得越来越多地挑战。尽管研究物种复合物固有的困难，但这些系统是将我们对生物多样性的理解与塑造其发展和多样性的基因组过程联系起来的理想选择。该项目旨在使用比较的系统发育系统（Crotalus viridis物种复合物）建立这些连接。该研究计划将使用全基因组单核苷酸多态性数据来生成该综合体的第一个健壮的物种树，这在历史上一直是系统主义者的有问题群体。然后，该系统发育框架将用作分析谱系内和谱系中正在选择的基因和基因组区域的比较平台。这项研究将询问多个人群和物种的基因组，以解决选择方案是否针对这种物种复合物中的共同基因座的问题，或者基因的基因和功能类别是否是由谱系靶向的。总的来说，这项研究将表征多样化和医学相关的有毒蛇组的进化史，并将大大增加我们对在多个尺度生物多样性产生生物多样性中适应和收敛进化的作用的了解。