PolyBayes

PolyBayes identifies single-nucleotide polymorphisms (SNPs) using Bayesian inference and base quality values to distinguish true allelic variation from sequencing errors for SNP discovery and genetic mapping.

Key Features:

• Unified SNP discovery: Uses genomic sequences as templates to map fragmentary or unmapped sequence data for SNP identification.
• Base quality utilization: Incorporates base quality values to differentiate true allelic variants from sequencing errors.
• Sequence organization: Performs fragment clustering, paralogue identification, and multiple alignment against genomic templates.
• Bayesian inference engine: Computes site-specific polymorphism probabilities using a Bayesian probabilistic model.
• Automated evaluation: Enables fully automated SNP evaluation without constraints on alignment depth through rigorous treatment of base quality values.
• High-throughput data processing: Scales to large datasets generated by high-throughput sequencing projects for SNP discovery.
• Assembly integration: Integrates with Phred/Phrap/Consed and DNA contig assembly workflows.

Scientific Applications:

• SNP discovery in human ESTs: Accurately predicts SNPs in human expressed sequence tags (ESTs).
• Genome-aligned sequence analysis: Analyzes sequences aligned to finished and working-draft genomic sequences for polymorphism detection.
• Genetic mapping and diversity studies: Facilitates mapping of complex traits and studies of genetic diversity via SNP identification.
• High-throughput project support: Applies to SNP discovery from large-scale sequencing and high-throughput sequencing projects.

Methodology:

Maps fragmentary sequence data to genomic sequences as templates and performs fragment clustering, paralogue identification, and multiple alignment; uses base quality values and a Bayesian inference engine to calculate site-specific polymorphism probabilities and enable automated evaluation without alignment depth constraints.