TY - JOUR
T1 - The spontaneous mutation rate in the fission yeast Schizosaccharomyces pombe
AU - Farlow, Ashley
AU - Long, Hongan
AU - Arnoux, Stéphanie
AU - Sung, Way
AU - Doak, Thomas G.
AU - Nordborg, Magnus
AU - Lynch, Michael
N1 - Publisher Copyright:
© 2015 by the Genetics Society of America.
PY - 2015/10
Y1 - 2015/10
N2 - The rate at which new mutations arise in the genome is a key factor in the evolution and adaptation of species. Here we describe the rate and spectrum of spontaneous mutations for the fission yeast Schizosaccharomyces pombe, a key model organism with many similarities to higher eukaryotes. We undertook an 1700-generation mutation accumulation (MA) experiment with a haploid S. pombe, generating 422 single-base substitutions and 119 insertion-deletion mutations (indels) across the 96 replicates. This equates to a base-substitution mutation rate of 2.00 3 10210 mutations per site per generation, similar to that reported for the distantly related budding yeast Saccharomyces cerevisiae. However, these two yeast species differ dramatically in their spectrum of base substitutions, the types of indels (S. pombe is more prone to insertions), and the pattern of selection required to counteract a strong AT-biased mutation rate. Overall, our results indicate that GC-biased gene conversion does not play a major role in shaping the nucleotide composition of the S. pombe genome and suggest that the mechanisms of DNA maintenance may have diverged significantly between fission and budding yeasts. Unexpectedly, CpG sites appear to be excessively liable to mutation in both species despite the likely absence of DNA methylation.
AB - The rate at which new mutations arise in the genome is a key factor in the evolution and adaptation of species. Here we describe the rate and spectrum of spontaneous mutations for the fission yeast Schizosaccharomyces pombe, a key model organism with many similarities to higher eukaryotes. We undertook an 1700-generation mutation accumulation (MA) experiment with a haploid S. pombe, generating 422 single-base substitutions and 119 insertion-deletion mutations (indels) across the 96 replicates. This equates to a base-substitution mutation rate of 2.00 3 10210 mutations per site per generation, similar to that reported for the distantly related budding yeast Saccharomyces cerevisiae. However, these two yeast species differ dramatically in their spectrum of base substitutions, the types of indels (S. pombe is more prone to insertions), and the pattern of selection required to counteract a strong AT-biased mutation rate. Overall, our results indicate that GC-biased gene conversion does not play a major role in shaping the nucleotide composition of the S. pombe genome and suggest that the mechanisms of DNA maintenance may have diverged significantly between fission and budding yeasts. Unexpectedly, CpG sites appear to be excessively liable to mutation in both species despite the likely absence of DNA methylation.
KW - Biased gene conversion
KW - Effective population size
KW - Fission yeast
KW - Mutation accumulation
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U2 - 10.1534/genetics.115.177329
DO - 10.1534/genetics.115.177329
M3 - Article
C2 - 26265703
AN - SCOPUS:84941668361
SN - 0016-6731
VL - 201
SP - 737
EP - 744
JO - Genetics
JF - Genetics
IS - 2
ER -