Genetic variability and phylogeography of Didelphis albiventris (Didelphidae) in Argentina.

CHEMISQUY, M. A.

Ciudad Autónoma de Buenos Aires

Jornada; XXXV Annual Meeting of the Willi Hennig Society; 2016

MACN

The white eared opossum, Didelphisalbiventris, is widely distributed in South America, being a common speciesin Argentina. It tolerates disturbed and fragmented habitats, includingcultivated lands and large cities, exploiting human habitation for foodresources. My goal is to analyze the genetic variability of D. albiventris and the phylogeographicpatterns of populations from Argentina and neighboring countries. I analyzedsequences from three mitochondrial markers, COI, cytB and D-loop, usingsequences from Argentina and other countries. Sequences from other species of Didelphis were used to compare intra-and interspecific genetic distances. Haplotype networks and other populationparameters were obtained. The three markers showed little genetic variabilityfor the Argentinean populations, ranging from 0.002 to 0.006. When analyzedseparately, D-loop is the marker that shows most structure, but samples from distantand phytogeographically different populations, such as Chacomús (Buenos Aires)and Anillaco (La Rioja) share the same haplotype. The same pattern is observedwith the other markers. Tajima?s D was negative in the three analyses, and thenucleotidic diversity (p)extremely low (>0.005). Although the geographic sampling should be expanded,preliminary results show little population structure, where samples fromlocalities separated by over a thousand kilometers are placed together or separatedby very few mutational steps. This would reflect a rapid geographic expansion,probably due to the colonization of new environments after the last glacialmaximum.