Genome-wide miRNA seeds prediction in Archaea.

Growing evidence indicates that miRNA genes exist in the archaeal genome, though the functional role of such noncoding RNA remains unclear. Here, we integrated the phylogenetic information of available archaeal genomes to predict miRNA seeds (typically defined as the 2-8 nucleotides of mature miRNAs) on the genomic scale. Finally, we found 2649 candidate seeds with significant conservation signal. Eleven of 29 unique seeds from previous study support our result (P value <0.01), which demonstrates that the pipeline is suitable to predict experimentally detectable miRNA seeds. The statistical significance of the overlap between the detected archaeal seeds and known eukaryotic seeds shows that the miRNA may evolve before the divergence of these two domains of cellular life. In addition, miRNA targets are enriched for genes involved in transcriptional regulation, which is consistent with the situation in eukaryote. Our research will enhance the regulatory network analysis in Archaea.