Molecular identification and phylogenetic relationships among the species of the genus Oligoryzomys (Rodentia, Cricetidae) present in Argentina, putative reservoirs of hantaviruses.

RIVERA, P.C., GONZÁLEZ-ITTIG, R.E., ROSSI-FRAIRE, H.J., LEVIS, SILVANA Y GARDENAL, C.N.

ZOOLOGICA SCRIPTA

Año: 2007 vol. 36 p. 231 - 239

0300-3256

Abstract. The systematics and geographic distribution of the species of Oligoryzomys present in Argentina are poorly known. From some of them, different hantavirus genotypes have been recovered. In order to contribute to the accurate identification of those species and to infer their phylogenetic relationships, we analyzed data of restriction sites and sequences of the mtDNA D-loop region. The samples used represent almost all Oligoryzomys species known to occur in Argentina. The trees obtained with the two types of data were similar, showing high bootstrap values for the majority of the nodes. Our results support the idea that the specific name Oligoryzomys longicaudatus should be applied only to individuals from the south of Argentina and Chile and confirm that Oligoryzomys nigripes and Oligoryzomys delticola are conspecific. Specimens identified as Oligoryzomys flavescens conform three related clades, probably belonging to a species complex. This study also emphasizes that the use of a DNA fragment characterized by a high evolutionary rate compare with other mitochondrial segments as the D-loop, was appropriate to infer the phylogenetic relationships in a group originated by a rapid speciation process. We also suggest the following modifications in the rodent-hantavirus relationships: the only viral genotype associated to O. longicaudatus would be Andes Sout, while Oligoryzomys chacoensis would be the natural host of the genotype Oran. One of the forms of the O. flavescens complex would be the natural host of the genotype Bermejo. Our data are consistent with the hypothesis that each hantavirus genotype is associated with a specific rodent host.