Table of Contents
International Journal of Evolutionary Biology
Volume 2012, Article ID 860797, 8 pages
Research Article

Whole-Genome Profiling of a Novel Mutagenesis Technique Using Proofreading-Deficient DNA Polymerase

1Genome Research Center, NODAI Research Institute, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
2Neo-Morgan Laboratory Inc., 907 Nogawa, Miyamae-ku, Kawasaki, Kanagawa 216-0001, Japan
3Department of Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan

Received 9 February 2012; Accepted 20 March 2012

Academic Editor: Hiromi Nishida

Copyright © 2012 Yuh Shiwa et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


A novel mutagenesis technique using error-prone DNA polymerase δ (polδ), the disparity mutagenesis model of evolution, has been successfully employed to generate novel microorganism strains with desired traits. However, little else is known about the spectra of mutagenic effects caused by disparity mutagenesis. We evaluated and compared the performance of the polδMKII mutator, which expresses the proofreading-deficient and low-fidelity polδ, in Saccharomyces cerevisiae haploid strain with that of the commonly used chemical mutagen ethyl methanesulfonate (EMS). This mutator strain possesses exogenous mutant polδ supplied from a plasmid, tthereby leaving the genomic one intact. We measured the mutation rate achieved by each mutagen and performed high-throughput next generation sequencing to analyze the genome-wide mutation spectra produced by the 2 mutagenesis methods. The mutation frequency of the mutator was approximately 7 times higher than that of EMS. Our analysis confirmed the strong G/C to A/T transition bias of EMS, whereas we found that the mutator mainly produces transversions, giving rise to more diverse amino acid substitution patterns. Our present study demonstrated that the polδMKII mutator is a useful and efficient method for rapid strain improvement based on in vivo mutagenesis.