GENOME-WIDE IDENTIFICATION AND EXPERIMENTAL VALIDATION OF MICRORNA TARGETS IN THE NEGLECTED DISEASE PATHOGENS OF THE GENUS ECHINOCOCCUS

MACCHIAROLI, NATALIA; CUCHER, M.; MAGDALENA ZAROWIECKI; MALDONADO, L.; KAMENETZKY, L.; ROSENZVIT, M. C.

Buenos Aires

Congreso; Reunión Conjunta de Sociedades de BioCiencias; 2017

MicroRNAs (miRNAs) are key regulators of gene expression at post-transcriptionallevel and play essential roles in different biological processes. MiRNAssilence target mRNAs by binding to complementary sequences in the3′untranslated regions (3′UTRs). The parasitic helminths of the genus Echinococcus are the causative agents ofechinococcosis, a zoonotic neglected disease. Here, we aimed to define a set of3?UTRs and to predict miRNA targets in Echinococcus. We performed RNA-seq and developed a pipeline that integrates thetranscriptomic data with available genomic data. We define a set of 4375 3′UTRsin E. canadensis. We validated theexpression and the length of a random subset of 3′UTRs by RT-PCR. We performedan in silico prediction of miRNAtarget sites. We found 941 potential miRNA target sites distributed in 724 3′UTRs.MiR-71 and miR-2 had the higher number of target genes, accounting for ∼30% of all targetgenes.  Evolutionary conservation analysis of miRNA target sites in a set of orthologous3′UTRs of Echinococcus and Taenia showed a significant decrease in theaverage number of nucleotide substitutions at miRNA target sites compared withrandom regions within the 3′UTRs (p<0.05) indicating that these sites may befunctional and under selective pressure. In addition, functional analysis ofmiRNA targets in E. canadensis showedthat MAPK signaling pathway was significantly enriched (FDR<0.05) indicatingmiRNA roles in parasite growth and development.  This study provides a valuable resource to guide future experimentalstudies such as reporter assays or miRNA silencing and/or overexpression. MiRNAsinvolved in essential functions might be considered as novel therapeutictargets for echinococcosis control. Experimental validation of selected miRNAtarget interactions by reporter assay is ongoing.