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. 2013 Jan;41(Database issue):D358-65.
doi: 10.1093/nar/gks1116. Epub 2012 Nov 24.

OrthoDB: A Hierarchical Catalog of Animal, Fungal and Bacterial Orthologs

Free PMC article

OrthoDB: A Hierarchical Catalog of Animal, Fungal and Bacterial Orthologs

Robert M Waterhouse et al. Nucleic Acids Res. .
Free PMC article


The concept of orthology provides a foundation for formulating hypotheses on gene and genome evolution, and thus forms the cornerstone of comparative genomics, phylogenomics and metagenomics. We present the update of OrthoDB-the hierarchical catalog of orthologs ( From its conception, OrthoDB promoted delineation of orthologs at varying resolution by explicitly referring to the hierarchy of species radiations, now also adopted by other resources. The current release provides comprehensive coverage of animals and fungi representing 252 eukaryotic species, and is now extended to prokaryotes with the inclusion of 1115 bacteria. Functional annotations of orthologous groups are provided through mapping to InterPro, GO, OMIM and model organism phenotypes, with cross-references to major resources including UniProt, NCBI and FlyBase. Uniquely, OrthoDB provides computed evolutionary traits of orthologs, such as gene duplicability and loss profiles, divergence rates, sibling groups, and now extended with exon-intron architectures, syntenic orthologs and parent-child trees. The interactive web interface allows navigation along the species phylogenies, complex queries with various identifiers, annotation keywords and phrases, as well as with gene copy-number profiles and sequence homology searches. With the explosive growth of available data, OrthoDB also provides mapping of newly sequenced genomes and transcriptomes to the current orthologous groups.


Figure 1.
Figure 1.
Screenshot of a sample orthologous group results page, featuring functional and evolutionary annotations, the inferred parent–child gene tree and syntenic orthologs.
Figure 2.
Figure 2.
Hierarchical parent–child trees.

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