Background: Small nucleolar RNAs (snoRNAs) are a class of non-coding RNAs that guide the modification of specific nucleotides in ribosomal RNAs (rRNAs) and small nuclear RNAs (snRNAs). Although most non-coding RNAs undergo post-transcriptional modifications prior to maturation, the functional significance of these modifications remains unknown. Here, we introduce the snoRNA orthological gene database (snOPY) as a tool for studying RNA modifications.
Findings: snOPY provides comprehensive information about snoRNAs, snoRNA gene loci, and target RNAs. It also contains data for orthologues from various species, which enables users to analyze the evolution of snoRNA genes. In total, 13,770 snoRNA genes, 10,345 snoRNA gene loci, and 133 target RNAs have been registered. Users can search and access the data efficiently using a simple web interface with a series of internal links. snOPY is freely available on the web at http://snoopy.med.miyazaki-u.ac.jp.
Conclusions: snOPY is the database that provides information about the small nucleolar RNAs and their orthologues. It will help users to study RNA modifications and snoRNA gene evolution.