RESUMO
The rodent genus Oecomys (Sigmodontinae) comprises ~16 species that inhabit tropical and subtropical forests in Central America and South America. In this study specimens of Oecomys paricola Thomas, 1904 from Belém and Marajó island, northern Brazil, were investigated using cytogenetic, molecular and morphological analyses. Three karyotypes were found, two from Belém (2n = 68, fundamental number (FN) = 72 and 2n = 70, FN = 76) and a third from Marajó island (2n = 70, FN = 72). No molecular or morphological differences were found between the individuals with differing cytotypes from Belém, but differences were evident between the individuals from Belém and Marajó island. Specimens from Belém city region may represent two cryptic species because two different karyotypes are present in the absence of significant differences in morphology and molecular characteristics. The Marajó island and Belém populations may represent distinct species that have been separated for some time, and are in the process of morphological and molecular differentiation as a consequence of reproductive isolation at the geographic and chromosomal levels. Thus, the results suggest that O. paricola may be a complex of species.
Assuntos
Cromossomos de Mamíferos/genética , Citocromos b/genética , DNA Mitocondrial/genética , Sigmodontinae/genética , Animais , DNA Mitocondrial/química , Geografia , Cariótipo , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNA , Sigmodontinae/anatomia & histologia , Sigmodontinae/classificação , América do Sul , Especificidade da EspécieRESUMO
Foram estudadas 17 proteínas séricas e eritrocitárias em uma populaçäo natural de Cebus apella paraguayanus. Apenas o locus da GPI mostrou poliformismo (GPI*1 = 89% and GPI*2 = 11%). Uma análise comparativa das estimativas de variabilidade genética dentre os primatas mostrou que C. a paraguayanus (P = 5.9%; H = 1.1%) apresenta níveis de variaçäo genética comparáveis a Alouatta palliata e Leontopithecus rosalia, duas outras espécies do Novo Mundo