Identification and expression profiling of microRNAs in Hymenolepis

MACCHIAROLI, NATALIA; CUCHER, MARCELA; KAMENETZKY, LAURA; YONES, CRISTIAN; BUGNON, LEANDRO; STEGMAYER, GEORGINA; MILONE, DIEGO HUMBERTO; BERRIMAN, MATTHEW; OLSON, PETER; ROSENZVIT, MARA

Simposio; II Argentine Meeting on Biology of Non-Coding RNAs; 2018

Tapeworms (cestodes) of the genus Hymenolepis are the causative agents of hymenolepiasis, a zoonotic neglected disease. Hymenolepis nana is the most prevalent human tapeworm, especially affecting children. The genomes of Hymenolepis microstoma and H. nana have been recently sequenced and assembled. MicroRNAs (miRNAs), a class of small non-coding RNAs, are principle regulators of gene expression at the post transcriptional level and are involved in many different biological processes. In previous work, we experimentally identified miRNA genes in the cestodes Echinococcus, Taenia and Mesocestoides. However, current knowledge about miRNAs in Hymenolepis is limited. In this work, we described for the first time the full repertoire and expression profile of miRNAs in H. microstoma, and discovered miRNAs in H. nana. We found a reduced complement of 37 evolutionarily conserved miRNAs, putatively reflecting their low morphological complexity and parasitic lifestyle. We found a high expression of a few miRNAs in the larval stage of H. microstoma that is conserved in other cestodes suggesting that these miRNAs may have important roles in development, survival and for host-parasite interplay. We showed that most of the miRNAs in Hymenolepis are located in intergenic regions implying that they are independently transcribed. We found a Hymenolepis-specific cluster composed of three members of the mir-36 family. Also, we found that one of the neighboring genes of mir-10 was a Hox gene as in most bilaterial species. This study provides a valuable resource for further experimental research in cestode biology that might lead to improved detection and control of these neglected parasites. The comprehensive identification and expression analysis of Hymenolepis miRNAs can help to identify novel biomarkers for diagnosis and/or novel therapeutic targets for the control of hymenolepiasis.