Identification and characterization of microRNAs in Echinococcus granulosus sensu stricto G1 and Echinococcus canadensis G7 using a high throughput approach

MACCHIAROLI N; KAMENETZKY L; CUCHER M; MALDONADO L; PRADA L; ROSENZVIT M

Congreso; 13th International Congress of Parasitology (ICOPA); 2014

BACKGROUND: Echinococcus granulosus sensu stricto G1 and Echinococcus canadensis G7 are etiological agents of cystic echinococcosis in animals and humans worldwide. These cestode parasites have complex life cycles and differ in biological features such as host specificity. MicroRNAs are key regulators of gene expression and are likely to have a role in development. In this study, we have used a high throughput approach to identify and characterize microRNAs in Echinococcus spp. METHODS: Small RNA libraries from protoscoleces of E. granulosus s.s. G1 and from protoscoleces and cyst walls of E. canadensis G7 were sequenced using Illumina technology. For microRNA prediction, the processed reads were mapped to E. multilocularis reference genome and then, miRDeep2 core algorithm was used. The output list of candidate precursors was manually curated to generate a high confidence set of microRNAs. Differential expression analysis of microRNAs between species or stages was estimated with DESeq. RESULTS: In this study we identified 36 microRNAs including 13 novel ones. We found that two microRNAs were highly expressed accounting for about 50% of the total microRNA expression in each sample. Differential expression analysis showed 16 microRNAs with stage biased expression in E. canadensis G7. No significant differences in the expression of miRNAs were found between protoscoleces of E. granulosus s.s. G1 and E. canadensis G7. CONCLUSIONS: Our results show the existence and expression of a broader repertoire of microRNAs in Echinococcus spp. than previously reported, including some microRNAs considered as evolutionarily lost. Also, our results suggest that microRNAs could play important functional roles in development and could be evaluated as potential targets for therapy.