The Human Olfactory Data Explorer (HORDE)

The Human Olfactory Data Explorer (HORDE) catalogs human and comparative olfactory receptor (OR) gene and pseudogene repertoires and associated genetic variation to support genomic analyses of OR classification, variation, evolution, and function.

Key Features:

• Comprehensive OR repertoire: Contains the complete repertoire of human OR genes and pseudogenes and OR repertoires from four other vertebrate species.
• Automated pipeline: Extracts OR gene and pseudogene sequences from complete genomes.
• Gene symbol assignment: Assigns gene symbols based on sequence similarity for identification and classification across species.
• Card generator: Aggregates detailed annotations for individual ORs from external databases and scientific studies, including classifications and ortholog information.
• Variation catalog: Catalogs single nucleotide polymorphisms (SNPs), copy number variations (CNVs), and deleterious mutations derived from whole genome sequences obtained by next-generation sequencing technologies.
• Search engine: Enables targeted retrieval of OR sequences, annotations, and variation data.
• Evolution and function tools: Hosts specialized tools for analyses of OR evolution and functional properties.
• Structural annotation: Annotates ORs as G-Protein Coupled Receptors with 7-transmembrane topology.

Scientific Applications:

• Repertoire characterization: Comparative characterization of human and non-human vertebrate OR gene and pseudogene repertoires.
• Genetic variation analysis: Investigation of interindividual genetic variability in ORs via SNP, CNV, and deleterious mutation catalogs from whole genome sequencing.
• Comparative genomics and orthology: Identification and classification of orthologs and cross-species sequence similarity analyses.
• Evolutionary studies: Analysis of OR family evolutionary trajectories using the hosted evolutionary tools and annotated repertoires.
• Functional annotation: Classification and functional inference of ORs as GPCR 7-transmembrane receptors based on sequence and annotation data.

Methodology:

An automated pipeline extracts OR gene and pseudogene sequences from complete genomes and assigns gene symbols based on sequence similarity; a card generator aggregates annotations from external databases and studies; the resource catalogs SNPs, CNVs, and deleterious mutations derived from whole genome sequences produced by next-generation sequencing technologies; and a search engine retrieves OR-related sequences and annotations.