Bisulfighter

Bisulfighter detects methylated cytosines and identifies differentially methylated regions from bisulfite sequencing data to support epigenomic analyses.

Key Features:

• Methylated Cytosine Detection: Calls methylated cytosines (mCs) from bisulfite sequencing by aligning reads with the LAST alignment tool.
• Differentially Methylated Region (DMR) Detection: Detects DMRs between paired samples using a hidden Markov model (HMM) framework with parameters estimated by the expectation-maximization (EM) algorithm.
• Performance and Accuracy: Demonstrates increased sensitivity and precision with fewer false positives, more accurate methylation level estimates, and precise DMR localization based on evaluations of simulated and real datasets.
• Biological Relevance: DMR calls show strong correlation with differentially expressed genes and DNase I hypersensitivity sites, linking methylation changes to gene regulation and chromatin accessibility.
• Versatility: Maintains performance across varying sequencing depths and tissue types.

Scientific Applications:

• Gene expression regulation: Enables analysis of methylation patterns associated with regulation of gene expression.
• Cancer research: Supports identification of tumor-associated methylation changes and DMRs relevant to oncogenesis.
• Developmental biology: Facilitates study of methylation dynamics during development.
• Environmental epigenetics: Assesses methylation changes induced by environmental exposures on genomic methylation patterns.

Methodology:

Aligns bisulfite sequencing reads with LAST for mC calling; applies HMMs with EM parameter estimation to detect DMRs between paired samples; evaluated on simulated and real datasets.