Extreme conservation of miRNA complements in opisthorchiids.

MicroRNAs (miRNAs) are important gene regulators that are key players in animal development and diseases. They are excreted in extracellular vesicles and because they were shown to be taken up by host cells they have been proposed as mediators of parasite-host communication, and potential biomarkers for the detection of parasitic infections from host blood. Consequently, it is crucial to precisely know the miRNA complements of medically important agents such as the liver flukes of the Opisthorchiidae. Using publicly available and new datasets we curated and reannotated the surprisingly small and variable miRNA complements previously described for Opisthorchis viverrini, O. felineus and Clonorchis sinensis. We find three highly similar miRNA complements with 53 identical and two miRNA genes with species specific sequences that signify a set of potential biomarkers and promising candidates for further investigations.