WikiPathways

WikiPathways operates on a wiki-based editing paradigm, allowing any registered researcher to create, modify, and annotate pathway diagrams. This crowdsourced approach accelerates the incorporation of new findings from the literature. Each pathway is version-controlled, with a complete edit history and authorship tracking enabling transparent provenance. The platform supports both expert-curated and machine-generated pathway content, with community review mechanisms to resolve discrepancies and maintain quality.

Pathways are stored in Graphical Pathway Markup Language (GPML), an XML-based format designed specifically for biological pathway representation. GPML encodes both the topological structure (nodes, edges, interactions) and the visual layout (coordinates, shapes, colors) of a pathway. This dual representation ensures pathways are both computationally analyzable and human-readable. The format supports annotation of data nodes with database identifiers (Entrez Gene, Ensembl, UniProt) and interaction types (catalysis, inhibition, binding).

WikiPathways integrates with PathVisio, an open-source Java-based pathway editor for creating and editing GPML files locally. Key capabilities include:

• Drag-and-drop node placement with automatic identifier mapping
• Statistical visualization overlays for omics data
• Plugin architecture for custom analysis extensions
• Direct upload/download synchronization with the WikiPathways repository PathVisio enables offline curation workflows before publishing to the shared database.

The platform provides a comprehensive REST API for automated retrieval and integration of pathway data into bioinformatics pipelines. Endpoints support:

• Full-text search across pathway names, descriptions, and annotations
• Gene-based queries to find all pathways containing a specific gene product
• GPML and JSON format downloads for computational consumption
• Species filtering across 30+ supported organisms This API enables seamless integration with enrichment tools like Enrichr and custom analysis workflows.

WikiPathways leverages BridgeDb, a framework for mapping biological identifiers across databases. Each data node in a pathway is annotated with a standardized identifier that can be resolved to equivalent IDs in Ensembl, Entrez Gene, UniProt, and other resources. This semantic layer ensures that pathway queries return consistent results regardless of the identifier namespace used. BridgeDb mapping files are maintained for each supported species, enabling cross-reference resolution during enrichment analysis.

WikiPathways hosts curated pathways for over 30 species, including human, mouse, rat, zebrafish, fruit fly, yeast, and Arabidopsis thaliana. The platform supports both species-specific pathways and homology-mapped pathways where content from one organism is computationally projected onto another. This breadth makes it a versatile resource for comparative genomics and translational research, enabling cross-species pathway activity comparisons in multi-omics studies.