RESUMO
A RAPD analysis on six species of the rodent genus Oligoryzomys trapped in a wide area (ranging from 01 degrees N to 32 degrees S) of Brazilian territory was performed in order to determine the levels of genetic variability within and between its populations and species. One-hundred and ninety-three animals were collected in 13 different sites (corresponding to 17 samples) located at Pampas, Atlantic Rain Forest, Cerrado, and Amazon domains. Oligoryzomys sp., O. nigripes (8 populations), O. flavescens (4 populations), O. moojeni, O. stramineus, and O. fornesi were the taxa analyzed. Of the 20 primers tested, 4 generated a total of 75 polymorphic products simultaneously amplified in 151 specimens. Various diversity estimators analyzed showed considerable differences between species and populations, indicating a great genetic variation occurring in the Oligoryzomys taxa investigated. A cluster analysis was made using Nei's standard genetic distances, however, it did not correlate the genetic heterogeneity of the species and populations with the geographical areas.
Assuntos
Variação Genética , Genética Populacional , Sigmodontinae/genética , Animais , Frequência do Gene/genética , Marcadores Genéticos , Sondas de Oligonucleotídeos , Técnica de Amplificação ao Acaso de DNA Polimórfico , Sigmodontinae/classificaçãoRESUMO
A RAPD analysis on six species of the rodent genus Oligoryzomys trapped in a wide area (ranging from 01° N to 32° S) of Brazilian territory was performed in order to determine the levels of genetic variability within and between its populations and species. One-hundred and ninety-three animals were collected in 13 different sites (corresponding to 17 samples) located at Pampas, Atlantic Rain Forest, Cerrado, and Amazon domains. Oligoryzomys sp., O. nigripes (8 populations), O. flavescens (4 populations), O. moojeni, O. stramineus, and O. fornesi were the taxa analyzed. Of the 20 primers tested, 4 generated a total of 75 polymorphic products simultaneously amplified in 151 specimens. Various diversity estimators analyzed showed considerable differences between species and populations, indicating a great genetic variation occurring in the Oligoryzomys taxa investigated. A cluster analysis was made using Nei's standard genetic distances, however, it did not correlate the genetic heterogeneity of the species and populations with the geographical areas.
Foram realizadas análises com RAPD em seis espécies de roedores do gênero Oligoryzomys capturados em uma ampla área (estendendo-se de 01° N a 32° S) do território brasileiro com o objetivo de determinar os níveis de variabilidade genética dentro e entre as populações e espécies. Cento e noventa e três animais foram coletados em 13 locais diferentes (correspondendo a 17 amostras) localizados nos Pampas, Floresta Atlântica, Cerrado e Amazônia. Oligoryzomys sp., O. nigripes (8 populações), O. flavescens (4 populações), O. moojeni, O. stramineus e O. fornesi foram as espécies analisadas. Vinte primers foram testados, sendo que quatro deles geraram um total de 75 produtos polimórficos amplificados simultaneamente em 151 exemplares. Várias estimativas de diversidade apresentaram diferenças consideráveis entre as espécies e as populações, indicando uma grande variação genética entre os taxa de Oligoryzomys investigados. As análises de agrupamento utilizando a distância genética de Nei, entretanto, não correlacionaram a heterogeneidade genética das espécies e populações com as áreas geográficas.
Assuntos
Animais , Variação Genética , Genética Populacional , Sigmodontinae/genética , Marcadores Genéticos , Frequência do Gene/genética , Sondas de Oligonucleotídeos , Técnica de Amplificação ao Acaso de DNA Polimórfico , Sigmodontinae/classificaçãoRESUMO
The present study involved an electrophoretic survey of 22 protein loci in 269 individuals belonging to three species of the genus Akodon, A. aff. cursor (2n = 16), A. cursor (2n = 14/15), and A. montensis (2n = 24/25/26), collected in Eastern Brazil. The joint results of gene diversity, genetic distances, phenetic analyses, and phylogenetic trees suggested that A. aff. cursor has recently separated from A. cursor and that the three species have experienced a recent chromosomal divergence followed by low allozyme differentiation. These data are in agreement with their classification as sibling species.
Assuntos
Arvicolinae/genética , Variação Genética , Proteínas/genética , Alelos , Animais , Evolução Molecular , Camundongos , Polimorfismo GenéticoRESUMO
The karyotype of the pampas fox has 2n=74 and a NF=76. Except for Chrysocyon brachyurus, 2n=74 is a common diploid number for the South American Canidae. This number is higher than in the Vulpes group and lower than in the group of the typical Canis. No 'marker chromosomes' are present in the South American Canidae.
