Optimizing Genomic Methods for Mapping and Identification of Candidate Variants in ENU Mutagenesis Screens Using Inbred Mice

• Published in: G3 : genes - genomes - genetics Vol. 8; no. 2; pp. 401 - 409
• Main Authors: Geister, Krista A, Timms, Andrew E, Beier, David R
• Format: Journal Article
• Language: English
• Published: United States Genetics Society of America 01.02.2018; Oxford University Press
• Subjects: Colgalt1; Fbn2; Kif20b; Mus musculus; Mutant Screen Report; Plod3; Tgds; Fbn2; Mus musculus; Tgds; Colgalt1; Plod3; whole genome sequence; Kif20b
• ISSN: 2160-1836; 2160-1836
• DOI: 10.1534/g3.117.300292

Positional cloning of ENU-induced mutations has traditionally relied on analysis of polymorphic variation between two strains.  In contrast, the application of whole genome sequencing (WGS) has enabled gene discovery in mutant lines maintained on an inbred genetic background.  This approach utilizes genetic variation derived from ENU-induced variants for mapping, and reduces the likelihood of phenotypic variation, making it an ideal method for genetic modifier screening.  Here, we describe the results of such a screen, wherein we determined the minimal number of mutant genomic DNA samples to include in our analyses, and improved the sensitivity of our screen by individually barcoding each genomic DNA library.  We present several unique cases to illustrate this approach's efficacy, including the discovery of two distinct mutations that generate essentially identical mutant phenotypes, the ascertainment of a non-ENU-induced candidate variant through homozygosity mapping, and an approach to the identification of putative dominant genetic modifiers.