Deficiency in DNA methylation increases meiotic crossover rates in euchromatic but not in heterochromatic regions in Arabidopsis

摘要

Epigenetic modifications change gene expression, or activity, without altering the underlying genes. The modifications include DNA methylation or the addition of a methyl group to the DNA and remodeling of chromatin protein structures that pack DNA into the nucleus. These modifications play a central role in genome maintenance, but little is known about their influence on the rate of meiotic recombination. We used methylation mutants in the model plant Arabidopsis thaliana to test the hypothesis that hypomethyl-ation could lead to hyperrecombina-tion. Our analysis revealed a complex relationship between DNA methylation and recombination: Methylation reduction was associated with an increase in meiotic crossover rates in euchromatin but had no effect in heterochromatin regions.