IMPAM   23988
INSTITUTO DE INVESTIGACIONES EN MICROBIOLOGIA Y PARASITOLOGIA MEDICA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Bioinformatic analysis of Echinococcus genome data
Autor/es:
KAMENETZKY L.
Reunión:
Encuentro; FlatDB Meeting; 2012
Resumen:
In bilaterian
animals, such as humans, flies and worms, hundreds of small RNAs, some
conserved throughout bilaterian evolution, collectively regulate gene
expression. In addition to microRNAs (miRNAs), other bilaterian small RNAs
known as Piwi-interactig RNAs (piRNAs) seem to protect the genome regulating
transposon expression. Here we obtained small RNAs libraries from the flatworm
cestode Echinococcus granulosus, the
causative agent of human hydatid disease. A subset of 283 RNA sequences ranging
from 19 to 45 nucleotides were analyzed. Among them 185 were classified as
miRNAs (Cucher et al., 2011). The remaining sequences with no rRNA/tRNA/mRNA
hits were exhaustively analyzed and 24 were classified as putative piRNAs.
Among them, 15 sequences (~ 60%) resembled bilaterian conservative piRNAs. Also
they mapped to repetitive genome loci and/or have an adenine in position 10,
like previously reported piRNAs . Interestingly, we found putative piRNAs
homologous to human germline cells specific piRNAs (Girard et al., 2006). Additionally,
we searched for piRNA biogenesis machinery components in the recently generated
Echinococcus genomes and found the Piwi
proteins orthologs represented in both E.
granulosus and E. multilocularis species.
This is the first report of the presence of piRNA-like small RNAs in cestodes. High
throughput small RNA sequencing of periodate treated libraries are being
designed to confirm these results. We show these findings in the context of the
biological source of small RNAs: a parasite stage which has the ability to
develop towards two drastically different developmental directions, sexual
adult worm or asexual metacestode depending on the host environment.