Identification of novel rhesus macaque microRNAs from naïve whole blood.

MicroRNAs (miRNAs) are emerging as novel molecular tools for diagnosing and treating diseases. Rhesus monkeys (Macaca mulatta) are the most widely used nonhuman primate species for biomedical studies, yet only 912 mature miRNAs have been identified in this species compared to 2654 in humans and 1978 in mice. The aim of this project was to help bridge that gap in knowledge by evaluating circulating miRNA in naïve rhesus monkeys and comparing results with currently available databases in different species in order to identify novel, mature miRNAs. Total RNA was isolated from whole blood of ten healthy, adult rhesus macaques. After performing next generation sequencing (NGS), 475 novel, mature miRNAs were identified in rhesus macaques for the first time; of those, 423 were identified for the first time in any species. The most abundantly expressed novel rhesus macaque miRNA, hsa-miR-744-5p, has previously been described in humans. Database assessment of hsa-miR-744-5p potential gene targets showed that while the gene targets showed > 90% sequence similarity between rhesus and humans, many did not share the same consensus sequences. The identification of 475 novel miRNAs in the blood of rhesus macaque reflects the complexity and variety of miRNAs across species. Further NGS studies are needed to reveal novel miRNA that will inform on species-, tissue-, and condition-specific miRNAs.