Related Experiment Video
Updated: Oct 6, 2025

Pattern-based Search of Epigenomic Data Using GeNemo
Published on: October 8, 2017
MONI: A Pangenomic Index for Finding Maximal Exact Matches
Massimiliano Rossi1, Marco Oliva1, Ben Langmead2
1Department of Computer and Information Science and Engineering, University of Florida, Gainesville, Florida, USA.
We developed a new algorithm to efficiently find maximal exact matches (MEMs) in large genomic datasets. Our method, MONI, significantly reduces memory usage and speeds up index construction for repetitive sequences.
Area of Science:
- Bioinformatics
- Computational Biology
- Genomics
Background:
- The r-index, an efficient data structure for storing large genomes, has limitations for finding maximal exact matches (MEMs).
- Previous methods required separate steps to find thresholds, hindering efficient MEM identification.
Purpose of the Study:
- To develop a novel algorithm for simultaneous construction of the r-index and its associated thresholds.
- To enable efficient maximal exact match (MEM) finding in large, repetitive sequence collections.
Main Methods:
- Applied prefix-free parsing (PFP) to construct the r-index and identify thresholds concurrently.
- Developed an implementation named MONI for rapid MEM finding.
Main Results:
- MONI achieved linear time and space complexity relative to the prefix-free parse size.
- MONI demonstrated significant improvements over existing read aligners in memory usage (2-11x less) and index construction speed (2-32x faster).
- MONI's index size was drastically smaller (less than 1/1000th) for large human chromosome collections.
Conclusions:
- MONI offers a major advancement for efficient MEM finding in large, related reference genomes.
- The simultaneous PFP-based approach for r-index and threshold construction is highly effective.
Related Concept Videos
Modern Molecular Taxonomy
Genomics
Evolutionary Relationships through Genome Comparisons
Multi-species Conserved Sequences
Although the genome of each species varies greatly from each other, a few sequences are highly conserved. Such conserved...
Proteomics
Proteomics is the study of proteomes' function. It involves the large-scale systematic study of the proteome to denote the protein complement expressed by a genome. Scientist Mark Wilkins coined the term...
Comparing Mitochondrial, Chloroplast, and Prokaryotic Genomes

