Identification of Echinococcus granulosus microRNAs and their expression in different life cycle stages and parasite genotypes

M CUCHER; L PRADA; G MOURGLIA-ETTLIN; S DEMATTEIS; F CAMICIA; S ASURMENDI; M ROSENZVIT

INTERNATIONAL JOURNAL FOR PARASITOLOGY

ELSEVIER SCI LTD

Año: 2011 vol. 41 p. 439 - 448

0020-7519

The aetiological agent of cystic hydatid disease, the platyhelminth parasite Echinococcus  granulosus, undergoes a series of metamorphic events during its complex life cycle. One of its  developmental stages, the protoscolex, shows a remarkable degree of heterogeneous morphogenesis,  being able to develop either into the vesicular or strobilar direction. Another level of complexity is  added by the existence of genotypes or strains that differ in the range of intermediate hosts where they  can develop and form fertile cysts. These features make E. granulosus an interesting model for  developmental studies. Hence, we focused on study of the regulation of gene expression by   microRNAs (miRNAs), one of the key mechanisms that control development in metazoans and plants  and which has not been analysed in E. granulosus yet. In this study, we cloned 38 distinct miRNAs,  including four candidate new miRNAs that seem to be specific to Echinococcus spp. Thirty-four cloned  sequences were orthologous to miRNAs already described in other organisms and were grouped in 16  metazoan miRNA families, some of them known for their role in the development of other organisms.  The expression of some of the cloned miRNAs differs according to the parasite life cycle stage  analysed, showing differential developmental expression. We did not detect differences in the  expression of the analysed miRNAs between protoscoleces of two parasite genotypes. This work sets  the scene for the study of gene regulation mediated by miRNAs in E. granulosus and provides a new  approach to study the molecules involved in its developmental plasticity and intermediate host   specificity. Understanding the developmental processes of E. granulosus may help to find new  strategies for the control of cystic hydatid disease, caused by the metacestode stage of the parasite.