Influences of landscape characteristics and historical barriers on the population genetic structure in the endangered sand-dune subterranean rodent Ctenomys australis

AUSTRICH, AILIN; MORA, MATÍAS S.; MAPELLI, FERNANDO J.; FAMELI, ALBERTO; KITTLEIN, MARCELO J.

GENETICA

SPRINGER

Año: 2020

0016-6707

Understanding the processes and patterns of local adaptation and migration involves an exhaustive knowledge of howlandscape features and population distances shape the genetic variation at the geographical level. Ctenomys australis is anendangered subterranean rodent characterized by having a restricted geographic range immerse in a highly fragmented sanddune landscape in the Southeast of Buenos Aires province, Argentina. We use 13 microsatellite loci in a total of 194 individualsfrom 13 sampling sites to assess the dispersal patterns and population structure in the complete geographic range of thisendemic species. Our analyses show that populations are highly structured with low rates of gene flow among them. Geneticdifferentiation among sampling sites was consistent with an isolation by distance pattern, however, an important fraction ofthe population differentiation was explained by natural barriers such as rivers and streams. Although the individuals weresampled at locations distanced from each other, we also use some landscape genetics approaches to evaluate the effects oflandscape configuration on the genetic connectivity among populations. These analyses showed that the sand dune habitatavailability (the most suitable habitat for the occupation of the species), was one of the main factors that explained the differentiationpatterns of the different sampling sites located on both sides of the Quequén Salado River. Finally, habitat availabilitywas directly associated with the width of the sand dune landscape in the Southeast of Buenos Aires province, findingthe greatest genetic differentiation among the populations of the Northeast, where this landscape is narrower.