SMALL RNAS OF CESTODE PARASITES AND POTENTIAL APPLICATIONS TO CONTROL

NATALIA MACCHIAROLI; MARCELA CUCHER; LAURA PRADA; LUCAS MALDONADO; LAURA KAMENETZKY; MARA ROSENZVIT

Congreso; X Congreso de Protozoologia y enfermedades parasitarias; 2014

Small RNAs of cestode parasites and potential applications to control Natalia Macchiaroli, Marcela Cucher, Laura Prada, Lucas Maldonado, Laura Kamenetzky and Mara Rosenzvit Instituto de Microbiología y Parasitología Médica (IMPaM), UBA-CONICET, Paraguay 2155, Piso 13. CP 1121. Buenos Aires, Argentina. mRosenzvit@fmed.uba.ar Tapeworms (Cestoda) cause neglected diseases such as cystic echinococcosis or cystic hydatid disease, alveolar echinococcosis and neurocysticercosis, caused by the larval stages of Echinococcus granulosus, Echinococcus multilocularis and Taenia solium, respectively. Understanding the mechanisms that regulate their particular characteristics of development may allow identifying new therapeutic targets. MicroRNAs are small silencing RNAs that impact eukaryotic development and are receiving growing attention as novel therapeutic and diagnosis targets. We have employed high throughput small RNA sequencing to characterize the small RNAomes of Echinococcus spp. species/stages using recently available genomic information (Tsai et al, 2013). There were obtained up to 40 million reads per library with high percentage of genome mapping. Significant proportions of small RNA reads corresponded to microRNAs. The previously reported Echinococcus spp. microRNA catalog consisting of 20 miRNAs (Cucher et al, 2011) was expanded to 34 conserved and 5 new candidate microRNAs. Interestingly, one microRNA was present in the closely related Echinococcus granulosus G1 and E. canadensis G7 but absent from Echinococcus multilocularis. Expression analyses showed that some miRNAs were highly expressed in all the stages and species analysed. MicroRNAs differentially expressed between stages and species were also identified, suggesting they could play developmental roles. Echinococcus spp. microRNA biogenesis showed particularities that could impact on targeted genes. No evidence of other canonical small silencing RNAs like piRNAs has been obtained so far. Host origin tRNA fragments were detected in parasite stages facing the host surface. In conclusion, our results show that microRNAs are the principal small RNA silencing molecules in Echinococcus spp. Highly expressed cestode microRNAs absent or divergent in mammal hosts were indentified and could be candidates for drug and diagnosis targeting.