DNA methylation in oysters is influenced by genetics and sex

Abstract

Abstract Background DNA methylation in mammals and insects is influenced by both genetic factors and sex. However, the extent to which these variables affect DNA methylation in molluscs has not been fully explored. Results In this study, we examined the genomic DNA methylation patterns in two genetically distinct oyster strains using whole-genome bisulfite sequencing (WGBS). Our analysis revealed a sex-associated difference in methylation, with females exhibiting more hypo-methylation than males in somatic tissues. Among the two strains, approximately 20,000 differential methylation regions (DMRs) were identified, with half of these DMRs being conserved in the offspring. Moreover, regions with differential methylation in parents typically displayed intermediate methylation levels in their progeny. This observation aligns with the notion that DNA methylation levels in the F1 progeny were consistent with their parents in the consistently methylated regions, suggesting a heritable stability in these epigenetic marks. Conclusions The findings indicate that genome-wide DNA methylation is preserved through generations in oysters, hinting at its potential significance in selective breeding programs. Additionally, the evident gender-specific methylation differences observed in somatic tissues must be considered in oyster epigenetic research.