OMBlast

OMBlast aligns optical maps (signal locations on long DNA molecules 0.1–1 Mbp) to support scaffolding and the detection of large and complex structural variations (SVs), complementing short-read sequencing for genome assembly and structural analysis.

Key Features:

• Optical map alignment: Aligns signal location patterns from optical maps representing long DNA molecules (0.1–1 Mbp).
• Seed-and-extend algorithm: Implements a seed-and-extend approach adapted from sequence alignment with modifications tailored to optical mapping data.
• SV sensitivity: Detects large and complex structural variations (SVs) and improves handling of regions containing structural rearrangements.
• Scaffolding support: Provides alignments that can be used to scaffold assemblies and validate assembly structure against optical maps.
• Complementary to short-read sequencing: Designed to work alongside short-read sequencing technologies to improve assembly continuity and structural variant discovery.
• Performance: Demonstrated higher accuracy and faster mapping speeds and increased robustness relative to existing methods on synthetic and real datasets.

Scientific Applications:

• Genome scaffolding: Use aligned optical maps to order and orient contigs for improved genome assemblies.
• Structural variation discovery: Identify and localize large and complex SVs such as large insertions, deletions, and rearrangements.
• Assembly validation: Validate assembly structure and resolve ambiguities by comparing sequence assemblies to optical map alignments.
• Long-molecule pattern analysis: Analyze signal patterns on long DNA molecules (0.1–1 Mbp) for structural and organizational studies.

Methodology:

Uses a seed-and-extend alignment strategy adapted for optical mapping to efficiently align signal location patterns from long DNA molecules, with performance evaluated on synthetic and real datasets.