INVESTIGADORES
BORGHI Carlos Eduardo
congresos y reuniones científicas
Título:
Genetic differentiation among geographically and ecologically divergent populations of the small cavy, Microcavia australis
Autor/es:
P. L. SASSI; MARINA CHIAPPERO; C. E. BORGHI; NOEMÍ GARDENAL
Lugar:
Mendoza
Reunión:
Congreso; The 10 th International Mammalogical Congress; 2009
Institución organizadora:
CCT-MENDOZA-CONICET; International Federation of Mammalogists
Resumen:
The small cavy Microcavia australis, a colonial and fossorial rodent, inhabits over a large distribution range in South American arid zones, which are typically heterogeneous and unpredictable environments. The species is versatile in coping with seasonal and spatial variability through changes in morphology (digestive organs size), physiology (energy extraction efficiency) and behaviour (dietary selection). Furthermore, habitat and ecological variables explain differences in social behavior and in life history traits of this species. In order to complement previous studies on ecology and physiology, we analyzed the levels of genetic variability and differentiation among four populations of the small cavy that differ in habitat characteristics (altitude, vegetation and precipitation). We sequenced the mitochondrial control region (D-loop) and used the Inter Simple Sequence Repeats (ISSR) technique to study the variability in the non-coding nuclear genome. Analyses were performed with the program Arlequin. ISSR variability levels were high in all populations (M from 0.305 to 0.345). Nucleotide diversity in populations from high altitudes was one order of magnitude smaller than in lowlands populations (? 0.001 versus 0.01/0.028); haplotype diversity was also smaller in highland populations (h 0.700 versus 0.844/0.944). Both kinds of markers revealed similar levels and geographic patterns of polymorphism. Pairwise genetic differentiation varied greatly (FST from 0.039 to 0.439 for ISSR and from 9.000×10-5 to 0.933 for mtD-loop), all comparisons being statistically significant except for the two highland populations. Only one out of 17 haplotypes found was shared among populations; the remaining haplotypes were exclusive for one population. Our results show that the variability in morphological, physiological and behavioral traits found among M. australis populations is also reflected in the degree of genetic differentiation.