DNA methylation entropy is associated with DNA sequence features and developmental epigenetic divergence

Area of Science:

• Epigenetics
• Developmental Biology
• Genomics

Background:

• DNA methylation is crucial for establishing and maintaining tissue identity during development.
• While mean DNA methylation differences are well-studied, the role of methylation variability (entropy) is less understood.

Purpose of the Study:

• To investigate the association of DNA methylation entropy with genomic features in human tissues.
• To assess the contribution of methylation entropy to developmental patterns in mouse embryos.
• To explore the relationship between epigenetic entropy and gene expression variability during development.

Main Methods:

• Analysis of allele-specific DNA methylation in 49 human tissue datasets.
• Application of information theory to 42 mouse embryo methylation datasets.
• Correlation analysis between methylation entropy, DNA sequence features, chromatin states, and gene expression.

Main Results:

• Methylation entropy in human tissues correlates with DNA binding motifs, regulatory DNA elements, and CpG density.
• In mouse embryos, methylation entropy contributes significantly to temporal and tissue-specific developmental patterns, comparable to mean methylation.
• Methylation entropy is associated with conserved sequence and chromatin features between human and mouse.
• Epigenetic entropy is directly linked to gene expression variability in development.

Conclusions:

• DNA methylation entropy is a significant epigenetic feature associated with genomic characteristics and developmental processes.
• Epigenetic entropy plays a crucial role in developmental plasticity and gene expression variability.
• These findings highlight the importance of considering methylation variability, not just mean differences, for a comprehensive understanding of epigenetics in development.