Q-RRBS: a quantitative reduced representation bisulfite sequencing method for single-cell methylome analyses.

Area of Science:

• Epigenetics
• Genomics
• Molecular Biology

Background:

• Reduced representation bisulfite sequencing (RRBS) is a key technique for DNA methylome profiling.
• PCR-based duplication artifacts can compromise RRBS accuracy, especially with limited starting material.
• The impact of these artifacts on single-cell or ultra-trace samples remains poorly quantified.

Purpose of the Study:

• To develop and validate a novel method to quantify and eliminate PCR duplication artifacts in RRBS.
• To assess the accuracy of DNA methylation profiling with ultra-trace amounts of starting material.
• To demonstrate the utility of the new method for single-cell epigenomic analysis.

Main Methods:

• Developed quantitative RRBS (Q-RRBS) incorporating unique molecular identifiers (UMIs).
• Excluded PCR-induced duplication by utilizing UMIs.
• Applied Q-RRBS to varying amounts of starting DNA material.
• Assessed allele-specific methylation detection capabilities.

Main Results:

• Duplication artifacts were more pronounced with smaller DNA input quantities.
• Q-RRBS successfully eliminated PCR duplication artifacts using UMIs.
• The method achieved accurate DNA methylation profiling even with ultra-trace amounts of starting material.
• Q-RRBS accurately detected allele-specific methylation without requiring genetic variants.

Conclusions:

• Q-RRBS is a robust strategy for accurate DNA methylation profiling.
• The method is particularly suitable for single cells and samples with minimal cell input.
• UMIs are crucial for mitigating PCR duplication artifacts in low-input epigenomic studies.