Characterization of schistosomal microRNA by species, sex and developmental stage

To date, 115 miRNAs genes (precursors) have been registered in miRBase for Schistosoma mansoni, and 56 for Schistosoma japonicum (225 and 79 mature miRNA, respectively). miRNAs have not been systematically described in Schistosoma haematobium. Our aim in this study was to systematically characterize and quantify miRNA in Schistosoma by species, developmental stage and sex and to test the usefulness of this characterization in biomarker discovery for infection. We found read evidence for the expression of 65/225 (36 precursors) known S. mansoni miRNA and 76/79 (55 precursors) of the known S. japonicum miRNA. We report a handful of novel miRNA in each of these species and provide a curated list of S. haematobium miRNA. We report differences of miRNA expression by species, sex and developmental stages. Lastly, we present preliminary results of miRNA deep sequencing from infected specimens (mouse and human). Overall design: Total RNA from twenty Schistosoma specimens of different species, sex and developmental stages were obtained from the BEI Resources (https://www.beiresources.org/). Total RNA was also extracted from infected mouse livers and infected human serum. miRNAs were profiled by small RNA deep sequencing. Output files were analyzed using miRDeep2 followed by manual curation to identify previously reported and novel miRNA in parasite and clinical specimens. Funding source: I-CORE Program of the Planning and Budgeting Committee and the Israel Science Foundation (grant no. 41/11)