Project description:Epimutations are changes in chromatin modifications, such as DNA methylation or histone modifications. Some of these epigenetic changes can be inherited for several generations, and thus could contribute to evolutionary processes. Estimates of epimutation rates now exists in a few species, but epigenetic mechanism are not conserved across all life, and epigenetic marks funtion differently in different species. To understand the properties of epimutations in fungi, we performed a mutation accumulation experiment with the filamentous fungus Neurospora crassa and investigated spontaneous DNA methylation and trimethylation of lysine 9 on histone H3 (H3K9me3) changes in the mutation accumulation lines. We observed that centromeric regions are hotspots of spontaneous DNA methylation changes in N. crassa. In these hotspot regions, DNA methylation changes were transmitted across mitoses, but changes occurring in euchromatin were not maintained. The rate of DNA methylation changes was more than 10 000-fold faster than the genetic mutation rate. We did not observe spontaneous changes in H3K9me3 that were transmitted across mitoses. Our results show that while spontaneous epimutations occur in this species, they occur predominantly in gene poor heterochromatic regions, so their impact for evolutionary adaptation may be limited.
2026-03-02 | GSE313506 | GEO
Project description:Spontaneous mutation rate of the oleaginous yeast Rhodotorula toruloides
Project description:45 genome-wide microarray measurements for 23 mutation accumulation lines grown in YPD liquid culture MA lines obtained by single-colony transfer on YPD plates for 600 generations, starting from a BY4741 derived strain (see Zeyl C, DeVisser JA: Estimates of the rate and distribution of fitness effects of spontaneous mutation in Saccharomyces cerevisiae. Genetics 2001, 157:53–61)
Project description:45 genome-wide microarray measurements for 23 mutation accumulation lines grown in YPD liquid culture MA lines obtained by single-colony transfer on YPD plates for 600 generations, starting from a BY4741 derived strain (see Zeyl C, DeVisser JA: Estimates of the rate and distribution of fitness effects of spontaneous mutation in Saccharomyces cerevisiae. Genetics 2001, 157:53â61) Two biological replicates for each strain in a common reference design (no dye-swap)
Project description:We have conducted a genome-wide analysis of spontaneous copy number variation (CNV) in the laboratory mouse. We used high resolution microarrays to identify 38 CNVs between 14 colonies of the C57BL/6 strain spanning ~967 generations of inbreeding, and examined these loci in 12 additional strains. It is clear from our results that many CNVs arise through a highly non-random process: 18 of 38 were the product of recurrent mutation, and rates of change vary roughly four orders of magnitude across different loci. These recurrent CNVs are distributed throughout the genome, affect 43 genes, and fluctuate in copy number over mere hundreds of generations, observations that raise questions about their contribution to natural variation. Keywords: Representational oligonucleotide microarray analysis, comparative genomic hybridization, DNA copy number variation, structural variation, inbred mice, spontaneous mutation rate
Project description:We have conducted a genome-wide analysis of spontaneous copy number variation (CNV) in the laboratory mouse. We used high resolution microarrays to identify 38 CNVs between 14 colonies of the C57BL/6 strain spanning ~967 generations of inbreeding, and examined these loci in 12 additional strains. It is clear from our results that many CNVs arise through a highly non-random process: 18 of 38 were the product of recurrent mutation, and rates of change vary roughly four orders of magnitude across different loci. These recurrent CNVs are distributed throughout the genome, affect 43 genes, and fluctuate in copy number over mere hundreds of generations, observations that raise questions about their contribution to natural variation. Keywords: comparative genomic hybridization, DNA copy number variation, structural variation, inbred mice, spontaneous mutation rate