Whole genome SNPs analyses unravel Echinococcus species phylogeny

MALDONADO, L.; KAMENETZKY, L.; MACCHIAROLI, N.; ROSENZVIT, M. C.

Ciudad de Buenos Aires

Conferencia; IV ISCB-LA A2B2C Bioinformatics Conference; 2016

Background:The parasite Echinococcus canadensis (G7) (phylum Platyhelminthes, class Cestoda) is one of the causative agents of echinococcosis, aworldwide chronic zoonosis affecting humans and animals, together with Echinococcus granulosus (G1) and Echinococcus multilocularis.At present, there is nounequivocal taxonomic classification of Echinococcus species, neithergenomic analysis that could reveal particularities among these genus.Results: In the present study we performed whole genome SNPsanalyses by mapping reads from genomic DNA of Echinococcus species. Homozygous andheterozygous variant sites were identified and the effect on codingregions was predictedIn general terms, weobserved more SNPs between E. canadensis (G7) and E. granulosus (G1) than between E. canadensis and , not onlyin the whole genome but also in coding regions.Furthermore; we used the SNPs to perform phylogenetic analyses. Homozygous SNPswere selected and concatenated and resulting alignment was used to createphylogenetic trees. This analysis showed a higher genetic distance between E. canadensis (G7) and E. granulosus(G1), than with E. multilocularis.  For further SNP validation; we performed PCRamplification followed by direct sequencing of coding regions of some genes.All SNPs  selected, 1 Indel and 48 SNPs (24synonimous and 24 Non-synonimous) were confirmed by PCR.Conclusions: Conversely to early studies on Echinococcus phylogeny basedon few nuclear genes or complete mitochondrial genome  data, wholegenome SNPs studies allowed us to perform phylogenetic analyses that revealed amore distant phylogenetic relationship between E. granulosus (G1) and E.canadensis (G7) than expected.