Parental genome reprogramming drives allelic convergence while preserving parent-of-origin memory during human early embryonic development.

Parental DNA methylation converges by embryonic days 8 to 12, with paternal hypermethylation erased after fertilization and re-established during peri-implantation in humans.

• Why it matters: Understanding how parental epigenetic differences are reprogrammed is crucial for insights into early human development and potential implications for neurodevelopmental disorders.
• What they did: The study conducted an integrated analysis of DNA methylation and transcriptome dynamics across human pre- to peri-implantation stages, focusing on allelic differences and timing of methylation convergence.
• The result: Findings reveal that maternal-biased methylation persists at oocyte-specific regions, while paternal methylation is erased and re-established, with certain transposable elements remaining maternally hypermethylated, and parent-of-origin gene expression linked to neurodevelopmental disorder risk.