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Centromeres are hotspots of DNA methylation epimutations that are transmitted and occur at high rates in a filamentous fungus

ABSTRACT: 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.

ORGANISM(S): Neurospora crassa

PROVIDER: GSE313506 | GEO | 2026/03/02

REPOSITORIES: GEO

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Centromeres are hotspots of DNA methylation epimutations that are transmitted and occur at high rates in a filamentous fungus

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