Identity by descent in population data

人口数据中的血统身份

• 批准号: 10460603
• 负责人: Sharon Browning
• 金额: $ 43.82万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-25 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10460603
• 关键词: Base Pairing; Biology; Catalogs; Chromosomes; DNA; Data; Disease susceptibility; Distant; Environmental Exposure; Female; Frequencies; Gene Conversion; Genealogy; Generations; Genetic; Genetic Crossing Over; Genetic Recombination; Genome; Genomic Segment; Genotype; Geographic Locations; Goals; Health; Human; Human Biology; Individual; Inherited; Linkage Disequilibrium; Maps; Methodology; Methods; Mutation; Natural Selections; Other Genetics; Population; Population Heterogeneity; Population Sizes; Probability; Pseudoautosomal Region; Recording of previous events; Role; Sampling; Specificity; Surveys; Susceptibility Gene; Time; Variant; Work; X Chromosome; autosome; base; detection method; frontier; genetic analysis; grandparent; identity by descent; improved; male; migration; offspring; pathogen; population migration; prototype; reproductive success; sex; tool

Abstract Two individuals’ DNA is said to be identical by descent when the individuals inherited it from a shared ancestor such as a great-grandparent. Identity by descent (IBD) occurs in relatively long segments of several million base pairs when the shared ancestor lived within approximately the past 50 generations. Since ancestors from 50 generations ago can have many descendants, it is possible to find segments of IBD between many pairs of individuals without known relationships. The goal of this proposal is to develop three new applications of IBD segments. The first application is estimating recombination rates. Recombination rates vary across the genome, and the rates must be estimated in order to perform many other genetic analyses. We will develop methods that use IBD segments to estimate recombination rates from population sample data. We will also develop methods to rigorously compare IBD-based recombination maps across populations. We will estimate recombination rates in different human populations, and we will investigate regions of the genome where there are differences between populations. The second application is estimating sex-specific demographic history. Males and females can have different effective population sizes due to differing variability in reproductive success, and males and females often have different rates of migration. We will develop method to estimate sex-specific effective population sizes and mutation rates by comparing rates of IBD segments on the X chromosome (which is weighted towards female history) and the autosomes (which are equally weighted between male and female histories). This work will improve our understanding of the historical dynamics that have shaped populations. The third application is analyzing recent positive selection. Selected regions can be found by looking for elevated levels of IBD. We will develop statistical methodology to estimate the strength of selection, the mode of selection, and the frequency of the selected variants. We know that selection differs across geographic regions due to different pathogens and other environmental exposures, and we will analyze diverse populations to catalog selected regions and how they differ between populations.

抽象的 当两个人的 DNA 是从共同的后代继承时，就可以说他们的 DNA 在血统上是相同的。 祖先，例如曾祖父母。血统同一性 (IBD) 发生在相对较长的片段中 当共同祖先生活在大约过去 50 代时，有数百万个碱基对。 由于50代以前的祖先可以有很多后代，因此可以找到以下片段： IBD 发生在多对没有已知关系的个体之间。 该提案的目标是开发 IBD 细分市场的三种新应用。 第一个应用是估计重组率。重组率因基因组而异，并且 为了进行许多其他遗传分析，必须估计这些比率。我们将开发方法 使用 IBD 片段来估计群体样本数据的重组率。我们还将开发 严格比较不同人群中基于 IBD 的重组图谱的方法。我们将估计 不同人群中的重组率，我们将研究基因组中发生重组的区域 人群之间存在差异。 第二个应用是估计特定性别的人口统计历史。男性和女性都可以有 由于繁殖成功率的差异以及男性和女性的不同，有效人口规模也不同 女性的迁移率往往不同。我们将开发方法来估计特定性别的有效 通过比较 X 染色体（即 女性历史的权重）和常染色体（男性和男性之间的权重相等） 女性历史）。这项工作将增进我们对塑造历史动态的理解 人口。 第三个应用程序是分析最近的正选择。可以通过查找来找到选定的区域 IBD 水平升高。我们将开发统计方法来估计选择的强度、 选择模式，以及所选变体的频率。我们知道不同的人的选择是不同的 由于不同的病原体和其他环境暴露而产生的地理区域，我们将分析 不同的人群对选定的区域进行分类以及它们在人群之间的差异。