is a Data Source.
OMA (Orthologous MAtrix) is a database of orthologous genes among multiple species, providing a systematic classification of orthologs across complete genomes.
biological systems, organisms
Unknown
Unknown
Unknown
| ID | Name | URL | Category | Format | Description |
|---|---|---|---|---|---|
| oma.site | OMA Browser | oma | GraphicalInterface | ❔ | Web interface for exploring OMA data |
| oma.api.rest | OMA REST API | api | ProgrammingInterface | ❔ | RESTful API for accessing OMA data |
| oma.api.sparql | OMA SPARQL | sparql | ProgrammingInterface | ❔ | SPARQL endpoint for accessing OMA data |
| oma.groups.txt ⚠ | OMA Groups (Text) | OmaGroups.txt.gz | Product | ❔ | OMA orthology groups in plain text fo... |
| oma.groups.orthoxml ⚠ | OMA Groups (OrthoXML) | OmaGroups.orthoxml | Product | xml | OMA orthology groups in OrthoXML format |
| oma.hogs.orthoxml ⚠ | OMA HOGs (OrthoXML) | OmaHOGs.orthoxml | Product | xml | Hierarchical Orthologous Groups (HOGs... |
| oma.pairs.txt ⚠ | OMA Pairwise Orthologs | OrthologousPairs.txt.gz | Product | tsv | Pairwise orthologs in tab-separated t... |
| oma.proteins.fasta ⚠ | OMA Protein Sequences | oma-proteins.fa.gz | Product | fasta | Protein sequences from all genomes in... |
| oma.cdna.eukaryotes.fasta ⚠ | OMA cDNA Sequences (Eukaryotes) | oma-eukaryotes.cdna.fa.gz | Product | fasta | cDNA sequences for Eukaryotic genomes... |
| oma.cdna.prokaryotes.fasta ⚠ | OMA cDNA Sequences (Prokaryotes) | oma-prokaryotes.cdna.fa.gz | Product | fasta | cDNA sequences for Prokaryotic genome... |
| oma.hdf5 ⚠ | OMA Browser Database (HDF5) | OmaServer.h5 | Product | ❔ | OMA Browser database in HDF5 format |
| oma.rdf ⚠ | OMA RDF Data | OMA.ttl.gz | Product | ttl | OMA data in RDF format (Turtle syntax) |
| oma.mapping.uniprot ⚠ | OMA to UniProt Mapping | oma-uniprot.txt.gz | MappingProduct | tsv | Mapping of OMA identifiers to UniProt... |
OMA (Orthologous MAtrix) is a comprehensive database of orthologous gene relationships across multiple species. It provides a systematic and efficient approach to identifying orthologs among complete genomes, which are genes in different species that evolved from a common ancestor through speciation.
The OMA methodology employs an algorithm that starts with an all-against-all sequence alignment, followed by the identification of orthologous pairs and the construction of orthologous groups. The database includes:
OMA is maintained by the Dessimoz Lab at the University of Lausanne and the Swiss Institute of Bioinformatics (SIB), with biannual releases adding new genomes and improving data quality. The database is widely used for comparative genomics, phylogenetics, functional annotation transfer, and evolutionary studies.
Access to OMA data is provided through a user-friendly web interface, a REST API for programmatic access, and bulk downloads in various formats including text files, OrthoXML, FASTA, and RDF.
Created: May 07, 2025 | Last modified: February 20, 2026