RESUMEN
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.
Asunto(s)
Animales , Variación Genética , Genética de Población , Sigmodontinae/genética , Marcadores Genéticos , Frecuencia de los Genes/genética , Sondas de Oligonucleótidos , Técnica del ADN Polimorfo Amplificado Aleatorio , Sigmodontinae/clasificaciónRESUMEN
The clastogenic effect of the drug cis-diamminedichloroplatinum II (cisplatin, CDDP) was investigated in Wistar rat bone marrow cells. Male rats, 3 per treatment time, aged months and weighing 250-350 g were injected intraperitoneally with 6.0 mg/Kg CDDP solution, and the control group received isotonic saline. The animals were sacrificed 6, 12, 18, 24 and 48h after the injection. the chromosome preparation was obtained from bone marrow cells. Chromatid and chromosome aberrations were investigated in 300 metaphases per animal. A significant increase in number of chromosome aberration was observed from 6 to 24h, the majority being of the break and gap type. After 48 h a progressive reduction was observed, without differences from the negative control. These date confirm the mutagenic effect of CDDP in rats demonstrated for mice bone marrow by micronuclei assay, for murine ovary cells and mice spermatocytes