Genetic studies in the recently divergent Eligmodontia puerulus and E. moreni (Rodentia, Cricetidae, Sigmodontinae) from Puna and Monte deserts of South America

ARMELLA SIERRA A.B; CASTILLO E.R; LABARONI C; BARRANDEGUY MARIA EUGENIA; MARTÍ D. A.; OJEDA R.; LANZONE C

ZEITSCHRIFT FUR SAUGETIERKUNDE-INTERNATIONAL JOURNAL OF MAMMALIAN BIOLOGY

Elsevier

Año: 2017 vol. 87 p. 93 - 100

0044-3468

Eligmodontia is a genus of phyllotine rodentsadapted to arid environments with seven recognized species. The sister species E. puerulus and E. moreni are distributed in the adjacent highland Puna and lowlandMonte deserts respectively, and show remarkable morphological and chromosomaldifferences. However, analyses of the cytochrome b gene showed importantvariability, without reciprocal monophyly between them. In order to study theevolutionary processes involved in the diversification of both taxa, weanalyzed 1161 bp of the mitochondrial control region and flanking sequences (N=60),as well as 759 bp of the first exon of the nuclear gene IRBP (N=14). Individualsof both species from Jujuy, Catamarca and Mendoza Provinces of Argentina werepreviously karyotyped. Results showed that the mitochondrial sequences presenthigh haplotype and nucleotide diversity within all population, and no haplotypewas shared between both species. FST indicated that populations of bothspecies were moderately structured. The network was constituted by two majorhaplogroups, one composed by E. puerulussamples from Jujuy, and the other composed of sequences of all studiedpopulations. The Bayesian analysis showed three clusters, matching the network.Phylogenetic analysis recovered two clades with high support, in coincidence withthe network groups. There was only one close join between sequences of bothspecies, corresponding to samples from Catamarca. Thus, mitochondrial datasuggested hybridization between both species in Catamarca, with asymmetricintrogression. The IRBP showed low variability and, in the phylogeneticanalysis, the sequences of E. puerulusform a monophyletic group with intermediate support, whereas those of E. moreni collapse into a basal polytomy.Our data indicated a recent divergence and absence of introgression in the nucleargenomes. The results at the population level with mitochondrial sequences,together with integrative taxonomy at the species level in a biogeographiccontext, suggest that climatic and geologic changes could have had an importantrole in the determination of genetic variability patterns observed in theserodents.