Interchromosomal Transfer of Epigenetic States in Ascobolus: Transfer of DNA Methylation Is Mechanistically Related to Homologous Recombination

Colot, Vincent; Maloisel, Laurent; Rossignol, Jean‐Luc

doi:10.1016/s0092-8674(00)80161-0

Cited by 123 publications

(65 citation statements)

References 46 publications

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“…One implication of these findings is that gene body methylation, which is an ancestral property of eukaryotic genomes (24,25), could protect genome integrity by inhibiting supernumerary COs within exons. On a similar note, it has been shown that the controlled addition of DNA methylation leads to a decrease in meiotic recombination for a particular locus in Ascobulus (26,27).…”

Section: Discussionmentioning

confidence: 83%

Loss of DNA methylation affects the recombination landscape in Arabidopsis

Mirouze

Lieberman‐Lazarovich²,

Aversano³

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

179

140

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During sexual reproduction, one-half of the genetic material is deposited in gametes, and a complete set of chromosomes is restored upon fertilization. Reduction of the genetic information before gametogenesis occurs in meiosis, when cross-overs (COs) between homologous chromosomes secure an exchange of their genetic information. COs are not evenly distributed along chromosomes and are suppressed in chromosomal regions encompassing compact, hypermethylated centromeric and pericentromeric DNA. Therefore, it was postulated that DNA hypermethylation is inhibitory to COs. Here, when analyzing meiotic recombination in mutant plants with hypomethylated DNA, we observed unexpected and counterintuitive effects of DNA methylation losses on CO distribution. Recombination was further promoted in the hypomethylated chromosome arms while it was inhibited in heterochromatic regions encompassing pericentromeric DNA. Importantly, the total number of COs was not affected, implying that loss of DNA methylation led to a global redistribution of COs along chromosomes. To determine by which mechanisms altered levels of DNA methylation influence recombination-whether directly in cis or indirectly in trans by changing expression of genes encoding recombination components-we analyzed CO distribution in wild-type lines with randomly scattered and wellmapped hypomethylated chromosomal segments. The results of these experiments, supported by expression profiling data, suggest that DNA methylation affects meiotic recombination in cis. Because DNA methylation exhibits significant variation even within a single species, our results imply that it may influence the evolution of plant genomes through the control of meiotic recombination.epigenetic | chromatin | epigenetic recombinant inbred lines | met1-3 R egulation of meiotic recombination, as with other essential chromosomal activities like transcription and replication, depends on both DNA sequence and chromatin properties (1, 2). Although regulatory aspects of meiotic recombination have been studied in great detail, it is still not well understood how chromatin structure influences the frequency and distribution of recombination events, as reflected by the final number and distribution of cross-overs (COs) along chromosomes. Biased chromosomal positioning of COs has been recognized for many years; indeed, COs are most likely to occur in euchromatic chromosomal arms, distal to the recombinationally suppressed pericentromeric heterochromatin. These two chromatin compartments are characterized by differences in the abundance of genes and transposable elements (TEs). TEs accumulate in pericentromeric regions, whereas genes are enriched in distal euchromatin. Because suppressive epigenetic marks are primarily directed at silencing TEs, these two chromatin types also differ in their epigenetic signatures. Pericentromeric chromatin is enriched in the methylation of histone H3 at lysine 9 (H3K9me) and encompasses hypermethylated DNA. In contrast, distal chromatin exhibits active marks such as acet...

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Section: Discussionmentioning

confidence: 83%

Loss of DNA methylation affects the recombination landscape in Arabidopsis

Mirouze

Lieberman‐Lazarovich²,

Aversano³

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

179

140

View full text Add to dashboard Cite

show abstract

“…The loxP-mediated silencing in the mouse 58 (BOX 5) is reminiscent of the transfer of methylated sequences that occurs during recombination in Ascobolus immersus 61 . Here, transfer of DNA methylation from a methylated allele to an unmethylated allele of the b2 spore-colour gene occurred when the two alleles were together in meiotic cells.…”

Section: Evolution Of Polyploidsmentioning

confidence: 99%

Chromatin conversations: mechanisms and implications of paramutation

2004

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“…It has been proposed that DNA methylation, in addition to its repressive e ects on transcription, may suppress homologous recombination between repetitive elements in the genome (Colot and Rossignol, 1999). Work with the fungus Ascobolus immersus, provides evidence that DNA methylation can suppress recombination (Colot et al, 1996). Increased genomic instability seen in the hypomethylated genome of embryonic stem cells lacking Dnmt1 provides evidence for a genome protective capacity for methylation (Chen et al, 1998).…”

Section: Disruption Of Epigenetic States In Cancermentioning

confidence: 99%