MP — Mammalian Phenotype Ontology
Overview
The Mammalian Phenotype Ontology (MP) is a controlled vocabulary for describing the phenotypes of mice, rats, and other mammals in a machine-readable, hierarchically organised form, and it is the model-organism counterpart to the human-focused HPO. Developed by The Jackson Laboratory for Mouse Genome Informatics (MGI) and also used by the Rat Genome Database and the Online Mendelian Inheritance in Animals database, it provides over 14,200 pre-coordinated terms across 28 categories organised as a directed acyclic graph by biological system, including a nervous system branch covering neurological and behavioural phenotypes. MP terms are used to annotate the phenotypes of more than 74,800 mouse models, which makes the ontology central to identifying animal models of human disease. It is co-maintained with HPO through a published cross-species term mapping, allowing mouse phenotype data to be matched to human disease phenotypes for disease-gene prediction and model discovery.
Key Features
- Terms are organised in a directed acyclic graph hierarchy across 28 biological-system categories, with a dedicated nervous system branch.
- Stable versioned term identifiers in the format MP:XXXXXXX, with monthly releases.
- Available in OWL, OBO, and JSON formats from the MGI download page and the MP GitHub repository.
- MP and HPO terms are aligned through the Mouse-Human Ontology Mapping Initiative, which publishes the mappings in SSSOM format.
Connections
- endorsedBy: OBO Foundry
- correspondsWith: HPO (MP and HPO co-maintain a published cross-species phenotype mapping; neither is derived from the other)
Resources
- https://obofoundry.org/ontology/mp.html
- https://www.informatics.jax.org/vocab/mp_ontology/ (MGI MP browser)
- https://github.com/mgijax/mammalian-phenotype-ontology (source, OWL/OBO/JSON releases)
- https://doi.org/10.1242/dmm.052385 (Smith et al. 2025, Disease Models & Mechanisms)