Whole human genome 5'-mC methylation analysis using long read nanopore sequencing.

Area of Science:

• Genomics
• Epigenetics
• Molecular Biology

Background:

• Traditional methods like methylation microarray and bisulphite sequencing for studying 5-methylcytosine (5mC) face challenges.
• These challenges include potential DNA modification side effects and difficulties in mapping short reads in complex genomic regions.

Purpose of the Study:

• To evaluate nanopore sequencing as an alternative for 5mC analysis in the human genome.
• To assess the accuracy and reliability of nanopore sequencing for methylation studies, particularly at low coverage depths.

Main Methods:

• Nanopore sequencing of native DNA from a human cell line.
• Comparison of methylation frequencies obtained by nanopore sequencing with 450k microarray, digital restriction enzyme analysis of methylation, and reduced representation bisulphite sequencing.
• Analysis of correlation in various genomic regions, including CpG islands and transcription start sites.

Main Results:

• Nanopore sequencing at 10X coverage depth yielded 5mC methylation frequencies consistent with established methods.
• High correlation was observed across different GC content regions and genomic annotations.
• A minimum of five reads per CpG site ensured strong correlations (>0.89) in replicate runs.

Conclusions:

• Nanopore sequencing is a fast, robust, and reliable approach for studying 5mC in the human genome.
• The technology provides accurate methylation data even with low coverage depth.
• Nanopore sequencing overcomes limitations of previous methods, offering improved resolution in complex genomic areas.