miRBase

miRBase is a fully searchable online database of published microRNA (miRNA) sequences and annotation. It provides a comprehensive resource for researchers studying the biogenesis, function, and evolution of miRNAs in a wide range of organisms.

The database contains information on miRNA gene loci, precursor (pre-miRNA) and mature miRNA sequences, target gene predictions (although these are often derived from external tools), and experimental evidence of miRNA expression. miRBase assigns unique accession numbers to each miRNA and provides links to relevant publications and other genomic databases.

Historically, miRBase included both a registry and a target prediction database. The registry component maintains the official nomenclature for miRNAs, ensuring standardized naming conventions across the research community. New miRNA sequences, supported by experimental evidence meeting specific criteria, are submitted to miRBase for consideration and, if accepted, are assigned a unique identifier.

While the target prediction aspects of miRBase were discontinued, the mature miRNA sequences and annotation remain crucial for researchers. Researchers use the database to identify known miRNAs, design experiments to study their function, and analyze the role of miRNAs in various biological processes and diseases. The underlying data are freely available for download, facilitating computational analyses and integration with other bioinformatics resources.