GEM-Mapper v3

GEM-Mapper v3 aligns short-read sequencing reads (up to 1 kilobase) to large reference genomes to enable accurate mapping for genomic analyses including single-nucleotide variant (SNV) and insertion–deletion (InDel) detection.

Key Features:

• Adaptive Gapped Search: Employs an adaptive gapped search mechanism tailored to input characteristics and user-defined settings to identify gapped matches.
• Custom FM-Index Design: Uses a custom FM-Index to index reference genomes, enabling rapid searches and accurate mapping of sequences up to 1 kilobase.
• String Matching by Filtration: Implements string matching by filtration to perform fully tunable exhaustive searches that return all possible matches, including those with gaps.
• Performance and Speed: Reports several-fold faster throughput than comparable state-of-the-art mappers while maintaining mapping accuracy.

Scientific Applications:

• Variant Detection: Benchmarked for SNV and InDel detection and shown to provide consistent detection across large portions of the genome, with remaining challenges in certain genomic regions.
• Genomic Research and Diagnostics: Provides computationally efficient alignment for large-scale genomic research and clinical diagnostic analyses.
• Whole-Genome Sequencing: Applicable to high-throughput whole-genome sequencing workflows as an alternative to targeted next-generation sequencing.

Methodology:

Indexes reference genomes with a custom FM-Index, applies adaptive gapped search tailored to input characteristics, and uses string matching by filtration to perform tunable exhaustive searches that return all matches including gaps.