MirGeneDB 2.0: the metazoan microRNA complement

Area of Science:

• Genomics
• Molecular Biology
• Evolutionary Biology

Background:

• Small non-coding RNAs, including microRNAs (miRNAs), are crucial for animal development and disease.
• Conserved sequences and distinct features define true miRNAs, but annotation quality is a concern.
• Existing miRNA databases often contain inaccuracies, hindering research.

Purpose of the Study:

• To create a comprehensive and accurate database of microRNA genes across diverse animal species.
• To address the heterogeneity and improve the quality of available miRNA annotations.
• To provide a reliable resource for microRNA research, evolution, and biomedical applications.

Main Methods:

• Expanded the curated microRNA gene database, MirGeneDB, to include 45 organisms.
• Consistently annotated and named 10,899 microRNA genes.
• Analyzed phylogenetic relationships to reconstruct ancestral miRNA repertoires.

Main Results:

• Identified >2000 bona fide microRNAs previously missing from annotations.
• Revealed that many previous microRNA annotations contained false positives.
• Demonstrated high similarity in miRNA complements between closely related species.
• Established that curated miRNA complements can reconstruct ancestral miRNA repertoires.

Conclusions:

• MirGeneDB offers a robust platform for accurate microRNA research.
• The database enhances insights into miRNA biology, evolution, and potential biomedical applications.
• Accurate miRNA annotation is essential for advancing microRNA-related scientific discovery.