Sensitive quantitative analysis of murine LINE1 DNA methylation using high resolution melt analysis

Area of Science:

• Epigenetics
• Molecular Biology
• Genomics

Background:

• DNA methylation is crucial in gene regulation and disease pathogenesis.
• Current DNA methylation assays are often low-throughput and costly, limiting mouse studies.
• Long Interspersed Elements-1 (LINE1) are repetitive elements sensitive to methylation changes.

Purpose of the Study:

• To develop and validate a novel, high-resolution melt (HRM) assay for quantitative analysis of murine DNA methylation.
• To assess the sensitivity and applicability of the assay for detecting changes in LINE1 methylation.
• To establish a high-throughput, cost-effective tool for DNA methylation screening in mouse models.

Main Methods:

• Developed a quantitative high-resolution melt (HRM) assay targeting CpG methylation in Long Interspersed Elements-1 (LINE1).
• Utilized biased PCR primers and melt temperature differences for enhanced sensitivity to detect low-dose 5-aza-2'-deoxycytidine (5-aza) treatment.
• Validated the assay against Liquid Chromatography-Mass Spectrometry (LC-MS) for total 5-methyl-cytosine content and pyrosequencing for CpG methylation uniformity.

Main Results:

• The LINE1-HRM assay demonstrated high sensitivity in detecting DNA methylation changes in cell lines and various mouse tissues.
• A tissue-specific methylation hierarchy was observed: peripheral blood > kidney > liver > prostate > spleen.
• Strain (CBA vs. Balb/c) and sex (male vs. female) differences in overall DNA methylation levels were identified.

Conclusions:

• The developed LINE1-HRM assay is a sensitive, high-throughput, and cost-effective tool for analyzing murine DNA methylation.
• The assay can detect subtle methylation changes in LINE1 elements across multiple genomic regions and tissues.
• This assay facilitates mouse studies investigating DNA methylation modulators, critical doses, and affected tissues in disease research.