Isolation of microsatellite loci in Akodon azarae (Muridae, Sigmodontinae) and cross-amplification in other Akodontini species

VERA NOELIA; CHIAPPERO MARINA; PRIOTTO JOSÉ; GARDENAL CRISTINA

JOURNAL OF GENETICS

INDIAN ACAD SCIENCES

Año: 2011 vol. 90 p. 25 - 29

0022-1333

Fragmentation of natural habitats is an increasing problemworldwide, having profound consequences on the geneticand demographic structure of natural populations (Mech andHallet 2001). A representative example of a fragmentationprocess occurs in central Argentina, an area of approximately500,000 km2 formerly occupied by prairies, but currentlyconsisting almost exclusively of crops and livestockpastures separated by fencelines, roads and railroads, alongwhich native and introduced weeds grow: the ‘border’ habitats.One of the most important components of the fauna inthis region are rodents of the subfamily Sigmodontinae, ahighly speciose group of mostly South American distribution,assembled in seven different tribes (Reig 1984). Threeof the most abundant Sigmodontine species in agroecosystemsof central Argentina are Calomys musculinus and C.venustus (tribe Phyllotini), and Akodon azarae, pertaining tothe tribe Akodontini, the second most important accordingto the number of species (Reig 1984). Previous studies haveestablished that these species differ in several ecological andbehavioural characteristics like habitat use (A. azarae andC. venustus preferentially use borders while C. musculinusinhabits both borders and crop fields;Mills et al. 1992; Polopand Sabattini 1993; Busch et al. 1997), space use (homerange size vary by sex and breeding period in A. azarae andC. musculinus, and by population abundance in C. venustus;Priotto and Steinmann 1999; Priotto et al. 2002), mating system(promiscuous/polygynous in C. venustus and A. azaraeand promiscuous in C. musculinus; Priotto and Steinmann∗For correspondence. E-mail: ngardenal@efn.uncor.edu.1999; Priotto et al. 2002; Steinmann et al. 2009) and competition(A. azarae is competitively dominant over C. musculinus;Busch et al. 2005). On these bases, it is predictablethat these species will differentially perceive landscape fragmentation.Our research interest focusses on comparing themovement and the genetic structure of their populations inagroecosystems, as a model to assess the genetic consequencesof fragmentation on the fauna of the region.The development of codominant microsatellite DNAmarkers are an invaluable tool for studying fine-scale geneticdifferences. For this purpose we already isolated and characterizednine microsatellite loci in C. musculinus that alsoamplify in C. venustus (Chiappero et al. 2005, 2011). As partof our studies on population structure at a small spatial scale,we describe here results of the isolation and characterizationof 10 microsatellite loci in A. azarae. We also investigated ifthe polymorphic primers developed amplify in other speciesof the tribe Akodontini.This is, to our knowledge, the first report of microsatelliteloci designed for the genus Akodon. Since this taxonhas nearly 40 species distributed throughout South Americafrom Colombia to southern Argentina and Chile, occupyinga wide variety of habitats from 0 to 5000 m above sea level(Redford and Eisenberg 1984), our work has a potentialutility for population genetic studies in the genus.