Cytogenetic studies in six species of tropiduridae (Sauria)

RESUMO

Cytogenetic studies were performed on six tropidurid lizards Tropidurus mucujensis, T hispidus, T montanus, T semitaeniatus, T spinulosus and Uranoscodon superciliosus. Conventional and differential (C- and R-bands and Ag-NORs) staining techniques were employed for the characterization of the karyotypes. The analyses were carried out in order to establish the morphological characterization of macro and microchromosomes, the R- and C-banding patterns as well as the silver staining of nucleolus organizer regions (Ag-NORs). R-banding was obtained after in vitro incorporation of 5-bromodeoxyuridine (BrdU). For some species, the banding patterns are described for the first time. All species presented a diploid number of 2n=36, with a basic karyotype constituted by 12 metacentric or submetacentric macrochromosomes and 24 microchromosomes (12M+24m). Although these species present a conservative karyotype, most of them are distinguished by the morphology of the macro and microchromosomes, by location of Ag-NORs, and by amount and distribution of constitutive hetcrochromatin. Sex determination of the XXXY type was found in T hispidus, T montanusand U. superciliosus. The presence of species specific karyotypes in T spinulosus and U. superciliosus is suggested.