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Abstract Gene duplication is a source of evolutionary novelty. DNA methylation may play a role in the evolution of duplicate genes (paralogs) through its association with gene expression. While this relationship has been examined to varying extents in a few individual species, the generalizability of these results at either a broad phylogenetic scale with species of differing duplication histories or across a population remains unknown. We applied a comparative epigenomic approach to 43 angiosperm species across the phylogeny and a population of 928 Arabidopsis (Arabidopsis thaliana) accessions, examining the association of DNA methylation with paralog evolution. Genic DNA methylation was differentially associated with duplication type, the age of duplication, sequence evolution, and gene expression. Whole-genome duplicates were typically enriched for CG-only gene body methylated or unmethylated genes, while single-gene duplications were typically enriched for non-CG methylated or unmethylated genes. Non-CG methylation, in particular, was a characteristic of more recent single-gene duplicates. Core angiosperm gene families were differentiated into those which preferentially retain paralogs and “duplication-resistant” families, which convergently reverted to singletons following duplication. Duplication-resistant families that still have paralogous copies were, uncharacteristically for core angiosperm genes, enriched for non-CG methylation. Non-CG methylated paralogs had higher rates of sequence evolution, higher frequency of presence–absence variation, and more limited expression. This suggests that silencing by non-CG methylation may be important to maintaining dosage following duplication and be a precursor to fractionation. Our results indicate that genic methylation marks differing evolutionary trajectories and fates between paralogous genes and have a role in maintaining dosage following duplication.
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This content will become publicly available on August 1, 2026
Uncovering methylation-dependent genetic effects on regulatory element function in diverse genomes
A major goal in evolutionary biology and biomedicine is to understand the complex interactions between genetic variants, the epigenome, and gene expression. However, the causal relationships between these factors remain poorly understood. mSTARR-seq, a methylation-sensitive massively parallel reporter assay, is capable of identifying methylation-dependent regulatory activity at many thousands of genomic regions simultaneously and allows for the testing of causal relationships between DNA methylation and gene expression on a region-by-region basis. Here, we develop a multiplexed mSTARR-seq protocol to assay naturally occurring human genetic variation from 25 individuals from 10 localities in Europe and Africa. We identify 6957 regulatory elements in either the unmethylated or methylated state, and this set was enriched for enhancer and promoter chromatin annotations, as expected. The expression of 58% of these regulatory elements is modulated by methylation, which is generally associated with decreased transcription. Within our set of regulatory elements, we use allele-specific expression analyses to identify 8020 sites with genetic effects on gene regulation; further, we find that 42.3% of these genetic effects vary in direction or magnitude between methylated and unmethylated states. Sites exhibiting methylation-dependent genetic effects are enriched for GWAS and EWAS annotations, implicating them in human disease. Compared with data sets that assay DNA from a single European ancestry individual, our multiplexed assay is able to uncover more genetic effects and methylation-dependent genetic effects, highlighting the importance of including diverse genomes in assays that aim to understand gene regulatory processes.
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- Award ID(s):
- 2313953
- PAR ID:
- 10649278
- Publisher / Repository:
- Genome Research
- Date Published:
- Journal Name:
- Genome Research
- Volume:
- 35
- Issue:
- 8
- ISSN:
- 1088-9051
- Page Range / eLocation ID:
- 1781 to 1793
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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