文章基本信息

标题：Real-time resolution of point mutations that cause phenovariance in mice
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作者：Tao Wang ; Xiaowei Zhan ; Chun-Hui Bu 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2015
卷号：112
期号：5
页码：E440-E449
DOI：10.1073/pnas.1423216112
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：SignificanceIn forward genetics, a mutagen is used to randomly induce germline mutations that cause variant phenotypes. Forward genetics permits discovery of genes necessary for biological phenomena, but identifying the mutations that cause variant phenotypes is time-consuming and in the past usually occurred long after the phenotype was first recognized. Here we introduce a method and software tool, Linkage Analyzer, for identifying causative mutations present in the germline of mutant mice concurrent with recognition of variant phenotypes. It requires knowledge of genotype at all mutation sites in members of a pedigree prior to phenotypic assessment. Using this method and software, forward genetic studies in mice are limited only by the rates of mutant production and screening. With the wide availability of massively parallel sequencing technologies, genetic mapping has become the rate limiting step in mammalian forward genetics. Here we introduce a method for real-time identification of N-ethyl-N-nitrosourea-induced mutations that cause phenotypes in mice. All mutations are identified by whole exome G1 progenitor sequencing and their zygosity is established in G2/G3 mice before phenotypic assessment. Quantitative and qualitative traits, including lethal effects, in single or multiple combined pedigrees are then analyzed with Linkage Analyzer, a software program that detects significant linkage between individual mutations and aberrant phenotypic scores and presents processed data as Manhattan plots. As multiple alleles of genes are acquired through mutagenesis, pooled "superpedigrees" are created to analyze the effects. Our method is distinguished from conventional forward genetic methods because it permits (1) unbiased declaration of mappable phenotypes, including those that are incompletely penetrant (2), automated identification of causative mutations concurrent with phenotypic screening, without the need to outcross mutant mice to another strain and backcross them, and (3) exclusion of genes not involved in phenotypes of interest. We validated our approach and Linkage Analyzer for the identification of 47 mutations in 45 previously known genes causative for adaptive immune phenotypes; our analysis also implicated 474 genes not previously associated with immune function. The method described here permits forward genetic analysis in mice, limited only by the rates of mutant production and screening.
关键词：N -ethyl- N -nitrosourea ; genetic mapping ; forward genetics ; mutagenesis ; massively parallel sequencing