BCREval: a computational method to estimate the bisulfite conversion ratio in WGBS

Area of Science:

• Genomics
• Molecular Biology
• Bioinformatics

Background:

• Whole genome bisulfite sequencing (WGBS) measures genome-wide DNA methylation at single-base resolution.
• Accurate assessment of bisulfite conversion ratio (BCR) is crucial to prevent false positive methylation calls.
• Existing methods for evaluating BCR can be time-consuming and computationally intensive.

Purpose of the Study:

• To develop a rapid and robust computational method for evaluating the bisulfite conversion ratio (BCR) in WGBS data.
• To utilize telomeric repetitive DNA as an endogenous control for BCR assessment.
• To provide a quality control measure for WGBS experiments.

Main Methods:

• Developed BCREval, a computational tool to estimate the unconverted rate (UCR) using telomeric DNA as a native spike-in.
• Tested BCREval on public WGBS datasets to assess its stability and performance.
• Compared BCREval's efficiency and speed against Bismark, a widely used BCR evaluation tool.

Main Results:

• BCREval demonstrated high stability, with most assays achieving over 99.5% conversion efficiency.
• Non-CpG methylation at telomeres followed a binomial model, suggesting a random process with low probability.
• BCREval proved significantly faster and more efficient than the Bismark tool.

Conclusions:

• BCREval offers a simple, robust method for quality control of WGBS experiments by accurately estimating BCR.
• The method is faster and more efficient than current tools.
• BCREval can be readily integrated into existing WGBS analysis pipelines.