THE GENOME OF THE SYLVATIC SPECIES ECHINOCOCCUS OLIGARTHRUS: PHYLOGENETIC HISTORY OF ECHINOCCOCUS THROUGH WHOLE GENOME VARIANTS ANALYSIS

MALDONADO, LUCAS L.; ARRABAL, JUAN PABLO; LICHTENSTEIN GABRIEL; MARA C. ROSENZVIT; OLIVEIRA, GUILHERME CORRÊA DE; KAMENETZKY, LAURA

Mar del Plata

Encuentro; REUNIÓN ANUAL DE SOCIEDADES DE BIOCIENCIA 2019; 2019

SAIC

The first parasitic helminth genomesequence was published in 2007, since then only ~200 genomeshave become available, most of them being draft assemblies.Nevertheless, despite the medical and economical global impact ofhelminthic infections, parasites genomes in public databases areunder-represented. Recently, through an integrative approachinvolving morphological, genetic and ecological aspects, we havedemonstrated that the complete life cycle of Echinococcusoligarthrus (Cestoda: Taeniidae) is present in South America. Theneotropical E. oligarthrus parasite is capable of developing in anyfelid species and producing human infections. Neotropicalechinococcosis is poorly understood yet and only a few cases ofechinococcosis have been unequivocally identified as consequenceof E. oligarthrus infections. Regarding phylogenetics, the analysesof mitogenomes and nuclear data sets have resulted in discordanttopologies and there is no unequivocal taxonomic classification sofar. In this work, we sequenced and assembled the genome of E.oligarthrus that was isolated from agoutis (Dasyprocta azarae)naturally infected and performed the first comparative genomicstudy of a neotropical Echinococcus species. The E. oligarthrusgenome assembly consisted of 86.22 Mb which showed ⁓90% ofidentity and 76.3% of coverage with Echinococcus multilocularisand contained the 85.0% of the total expected genes. Geneticvariants analysis of whole genome revealed a higher rate ofintraspecific genetic variability (23,301 SNPs; 0.22 SNPs/Kb)rather than for the genomes of E. multilocularis and Echinococcuscanadensis G7 but lower with respect to Echinococcus granulosusG1. Comparative genomics against E. multilocularis, E. granulosusG1 and E. canadensis G7 revealed 38,762; 125,147 and 170,049homozygous polymorphic sites respectively, indicating a highergenetic distance between E. oligarthrus and Echinococcusgranulosus sensu lato species. Phylogenetic analysis using wholegenome SNPs demonstrated that E. oligarthrus is one of the basalspecies of the genus Echinococcus and is phylogenetically closer toE. multilocularis. This work sheds light on the Echinococcusphylogeny and settles the basis to study sylvatic Echinococcusspecies and their developmental evolutionary features.