The role of river drainages in shaping the genetic structure of capybara populations

BYRNE, MARÍA SOLEDAD; QUINTANA, RUBEN DARIO; BOLKOVIC, MARÍA LUISA; CASSINI, MARCELO; TUNEZ, IGNACIO

GENETICA

SPRINGER

Año: 2015 vol. 143 p. 645 - 656

0016-6707

The capybara, Hydrochoerus hydrochaeris, isan herbivorous rodent widely distributed throughout mostof South American wetlands that lives closely associatedwith aquatic environments. In this work, we studied thegenetic structure of the capybara throughout part of itsgeographic range in Argentina using a DNA fragment ofthe mitochondrial control region. Haplotypes obtainedwere compared with those available for populations fromParaguay and Venezuela. We found 22 haplotypes in 303individuals. Hierarchical AMOVAs were performed toevaluate the role of river drainages in shaping the geneticstructure of capybara populations at the regional and basinscales. In addition, two landscape genetic models, isolationby distance and isolation by resistance, were used to testwhether genetic distance was associated with Euclideandistance (i.e. isolation by distance) or river corridor distance(i.e. isolation by resistance) at the basin scale. At theregional scale, the results of the AMOVA groupingpopulations by mayor river basins showed significant differencesbetween them. At the basin scale, we also foundsignificant differences between sub-basins in Paraguay,together with a significant correlation between genetic andriver corridor distance. For Argentina and Venezuela,results were not significant. These results suggest that inParaguay, the current genetic structure of capybaras isassociated with the lack of dispersion corridors throughpermanent rivers. In contrast, limited structuring inArgentina and Venezuela is likely the result of periodicflooding facilitating dispersion.