Search

The Yungas, a subtropical mountain rainforest of South America, has been little studied in relation to the evolutionary history of the large-bodied species of the genus Calomys. Particularly, two species have been synonymized: C. boliviae and C. fecundus; the first is only known from its type locality in the northern Bolivian Yungas, whereas the second is known along the Tucumane–Bolivian Yungas shared by Bolivia and Argentina. In this study, we combined a phylogeographic approach with ecological niche modeling, with samples covering most of the geographic range of C. fecundus. One mitochondrial and two nuclear genes were used for population genetic analyses. Current and paleoclimatic models were obtained. Nuclear genes resulted uninformative by retention of ancestral polymorphism with other species of Calomys. The mitochondrial marker revealed a complex network showing signals of several population expansions. Three genetic clusters in a latitudinal sense were detected, which are coincident with the three stable climatic zones estimated by current and paleoclimatic models. We determined a pattern of expansion during glacial cycles and ancestral refugia during interglacial cycles. None of the potential distribution models predicted the presence of C. fecundus in the type locality of C. boliviae. Therefore, we recommend making integrative taxonomic studies in the Bolivian Yungas, to determine whether or not C. fecundus and C. boliviae correspond to the same species. Fil: Pinotti, Juan Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina Fil: Ferreiro, Alejandro Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina Fil: Martin, Maria Laura. Instituto Nacional de Enfermedades Virales Humanas Dr. Julio I. Maiztegui; Argentina Fil: Levis, Silvana del Carmen. Instituto Nacional de Enfermedades Virales Humanas Dr. Julio I. Maiztegui; Argentina Fil: Chiappero, Marina Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina. Universidad Nacional de Córdoba. Facultad de Cs.exactas Físicas y Naturales. Cátedra de Genética de Poblaciones y Evolución; Argentina Fil: Andreo, Verónica Carolina. Instituto Nacional de Medicina Tropical; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: González Ittig, Raúl Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina. Universidad Nacional de Córdoba. Facultad de Cs.exactas Físicas y Naturales. Cátedra de Genética de Poblaciones y Evolución; Argentina

Population genetic studies can contribute to current knowledge about the epidemiology of pathogens such as Streptococcus mutans, which is one of the most widely distributed bacteria in the world to be associated with human dental caries. In the present study, we investigated whether the population genetic structure of the species is clonal or recombinant, and we also evaluated the current levels of gene flow, admixed ancestry, and the hypothesis of an expansion of the bacteria within the last 10 000 years. Strains of S. mutans from Córdoba (Argentina) were obtained, with sequences of the genes aroE, gltA, gyrA, and lepC genes being aligned with those of strains from Japan, Thailand, and Finland. Most of our statistical analyses performed on the DNA matrix of 193 strains supported the existence of recombination at the intergene level. We also estimated the number of genetic clusters via Bayesian analyses, with three genetic clusters being detected in the four countries at different frequencies, as well as the number of strains with pure or admixed ancestry varying among countries. Argentina revealed 50% admixed strains, whereas these types of strains were present in only 8-19% of the other three countries analyzed. This result could be associated with the important human migration waves that Argentina has experienced, which may have mixed strains of S. mutans of different geographical origins. The demographic history was obtained using Extended Bayesian Skyline Plot anslysis, which showed important growth in the effective population size approximately 5000 years ago, coincident with the beginning of the dispersion of agriculture and a change to a diet rich in carbohydrates. Fil: González Ittig, Raúl Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina Fil: Carletto Korber, Fabiana Pia Marina. Universidad Nacional de Córdoba. Facultad de Odontología. Cátedra de Biología Celular; Argentina Fil: Vera, Noelia Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina Fil: Jimenez, Maria Graciela. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Hospital Universitario de Maternidad y Neonatología; Argentina Fil: Cornejo, Lila Susana. Universidad Nacional de Córdoba. Facultad de Odontología. Cátedra de Biología Celular; Argentina