RECOMBINANT DNA IN POPULATION GENETICS

群体遗传学中的重组 DNA

• 批准号: 2176191
• 负责人: ALAN Robert TEMPLETON
• 金额: $ 23.18万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1983
• 资助国家: 美国
• 起止时间: 1983-01-01 至 1995-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2176191
• 关键词: DNA footprinting; Drosophilidae; Orthoptera; alternatives to animals in research; animal population density; animal population genetics; biochemical evolution; crayfish; endonuclease; evolution; gene expression; gene frequency; genetic markers; genetic models; genetic polymorphism; lizards; mitochondrial DNA; nucleic acid hybridization; polymerase chain reaction; recombinant DNA; ribosomal DNA; species difference

Evolution is an historical process, and history greatly influences present- day observations. Genetic surveys using restriction mapping or DNA sequencing contain much historical information. Our general aim is to extract this historical information and use it in making evolutionary inferences on three interrelated problems in evolutionary genetics: population structure, founder and bottleneck events, and speciation. Population structure encompasses effective size, system of mating, and pattern of gene flow. Our first and primary aim is to develop phylogenetic techniques for the analysis of population structure by integrating cladistics (a methodology traditionally used to infer interspecific phylogenies) with coalescent theory (the subdiscipline of population genetics that deals with the genealogical structure of current genetic variants). These techniques will be applied to crayfishes, grasshoppers, and lizards. These species were chosen because biogeographical, behavioral, and/or habitat data indicate that this group covers a broad range of potential for restriction of gene flow on various geographical scales. The amount and distribution of genetic variation in a species today depends both upon its current population structure and upon past history (e.g., founder/bottleneck events). Our second specific aim is to develop phylogenetic methods of partitioning history from current population structure. We will use a nested cladistic analysis of geographical associations among haplotypes to detect recent historical events, use the branch length distribution of the cladogram (unrooted evolutionary tree) of the haplotypes to detect older historical events, and use recently evolved haplotypes to restrict inference to post-event gene flow patterns. To test these approaches, we will apply the techniques to several organisms for which we have excellent evidence of past historical events (either habitat fragmentation or colonization of new areas) on a known time scale that should cover a broad range in the predicted ease of detection of historical events. These species will also include crayfishes, grasshoppers and lizards, and broadly overlap with the organisms used for our first specific aim although the biogeographical scale differs. We will also test the validity of our assumptions by studying populations known to have undergone recent founder events; such as artificially released populations of collared lizards in the Ozarks and various captive zoo populations. The historical information encoded in the DNA extends beyond the existence of the species itself, and hence phylogenies of closely related species can be constructed from genetic data. We will construct such a phylogeny for a speciose and very diverse subgenus of crayfish and use the resulting phylogeny to test hypotheses about interactions among population structure, historical events, adaptative change, phenotypic change, geographical isolation, and speciation.

进化是一个历史过程，历史极大地影响着现在-- 白天的观察。使用限制性图谱或DNA进行遗传调查 测序包含了许多历史信息。我们的总体目标是 提取这些历史信息，并将其用于使 进化遗传学中三个相互关联的问题的推论： 种群结构、创始人和瓶颈事件以及物种形成。 种群结构包括有效规模、交配系统和 基因流动的模式。我们的首要目标是发展系统发育 基于集成的种群结构分析技术 分支学(一种传统上用来推断种间关系的方法 系统发育学)与联合理论(人口的分支学科 遗传学研究当前基因的谱系结构的遗传学 变体)。这些技术将应用于小龙虾、蚱蜢、 还有蜥蜴。选择这些物种是因为生物地理上的， 行为和/或栖息地数据表明，这一群体覆盖了广泛的 不同地域限制基因流动的潜力范围 比例。 今天一个物种的遗传变异的数量和分布取决于 根据其当前的人口结构和过去的历史(例如， 创始人/瓶颈事件)。我们的第二个具体目标是发展 划分历史和当前种群的系统发生学方法 结构。我们将使用嵌套的地理分支分析 单倍型之间的关联要检测最近的历史事件，请使用 红豆杉分支图(无根进化树)的分枝长度分布 单倍型来检测更古老的历史事件，并使用最近进化的 单倍型将推断限制在事件后的基因流动模式上。为了测试 这些方法，我们将把这些技术应用于几种生物 我们对过去的历史事件有很好的证据(无论是栖息地 新区域的碎片化或殖民化)在已知的时间尺度上 应该涵盖广泛的预测范围，以便于检测历史记录 事件。这些物种还将包括小龙虾、蚱蜢和 蜥蜴，并与用于我们第一个特定生物的生物广泛重叠 目的尽管生物地理尺度不同。我们还将测试 通过研究已知经历过的人口来验证我们的假设 最近的创始人事件；例如人工释放的种群 奥扎克和各种圈养动物园中的颈蜥蜴。 编码在DNA中的历史信息超出了存在的范围 物种本身，因此密切相关物种的系统发育可以 是由基因数据构建的。我们将构建这样一个系统发展图 一种特殊的和非常多样化的小龙虾亚属，并使用由此产生的 用来检验种群结构之间相互作用假说的进化史 历史事件，适应性变化，表型变化，地理 隔离和物种形成。