FlyBase miRNA annotations (precursor hairpin and mature miRNA products) are compared to the miRBase miRNA database periodically. Existing FlyBase miRNA annotations are modified to match corresponding miRBase annotations. New miRBase miRNA annotations are incorporated into FlyBase as new genes. Symbols for miRNA genes are, with a few exceptions, the same between FlyBase and miRBase, though the preceding species designation differs. For example, the D. melanogaster 'mir-1' gene in FlyBase corresponds to 'dme-mir-1' in miRBase and the D. virilis 'Dvir\mir-1' gene in FlyBase corresponds to 'dvi-mir-1' in miRBase.