Genome wide estimates of mutation rates and spectrum in Schizosaccharomyces pombe indicate CpG sites are highly mutagenic despite the absence of DNA methylation

BioRxiv : the Preprint Server for Biology
Megan G Behringer, David W Hall


We accumulated mutations for 1952 generations in 79 initially identical, haploid lines of the fission yeast Schizosaccharomyces pombe and then performed whole-genome sequencing to determine the mutation rates and spectrum. We captured 696 spontaneous mutations across the 79 mutation accumulation lines. We compared the mutation spectrum and rate to another model ascomycetous yeast, the budding yeast Saccharomyces cerevisiae. While the two organisms are approximately 600 million years diverged from each other, they share similar life histories, genome size and genomic G/C content. We found that Sc. pombe and S. cerevisiae have similar mutation rates, contrary to what was expected given Sc. pombe’s smaller reported effective population size. Sc. pombe’s also exhibits a strong insertion bias in comparison to S. cerevisiae,. Intriguingly, we observed an increased mutation rate at cytosine nucleotides, specifically CpG nucleotides, which is also seen in S. cerevisiae. However, the absence of methylation in Sc. pombe and the pattern of mutation at these sites, primarily C→ A as opposed to C→T, strongly suggest that the increased mutation rate is not caused by deamination of methylated cytosines. This result implies that the high mutab...Continue Reading

Related Concepts

Cytosine Nucleotides
Saccharomyces cerevisiae

Related Feeds

BioRxiv & MedRxiv Preprints

BioRxiv and MedRxiv are the preprint servers for biology and health sciences respectively, operated by Cold Spring Harbor Laboratory. Here are the latest preprint articles (which are not peer-reviewed) from BioRxiv and MedRxiv.

Related Papers

Proceedings of the National Academy of Sciences of the United States of America
Yuan O ZhuDmitri A Petrov
BioEssays : News and Reviews in Molecular, Cellular and Developmental Biology
J M Mitchison
© 2021 Meta ULC. All rights reserved