Characterization of Chromosomal and Repetitive Elements in the Genome of “Rana nigrovittata” (Anura, Ranidae): Revealed by Classical and Molecular Techniques

Karyotype study and microsatellites pattern in the genome of Rana nigrovittata were studied, with the aim to provide a standard karyotype, chromosome marker and the distribution of repetitive DNA elements, informative knowledge of cytogenetics and evolutionary events. Here, we analyzed the karyotype structure and the distribution of repetitive DNA sequence in this species using conventional banding and Fluorescence in situ hybridization techniques. The ten specimens (five males and five females) were collected from Phitsanulok province, Thailand. Mitotic metaphases were prepared from the bone marrows by the standard protocol. The result showed that R. nigrovittata had the diploid chromosome number of 2 n = 26 and the fundamental number (NF) were 52 in both males and females. The karyotypes compose of six large metacentric, four large submetacentric, two medium metacentric, two medium submetacentric and 12 small submetacentric chromosomes. No sex related chromosome heteromorphism was observed in male (XY) or female (ZW) of this species. The NOR was observed in subcentromeric region on chromosome no. 11. The C-positive heterochromatin blocks are mainly distributed in the centromere of most chromosomes, while some additionally in paracentromeric and telomeric regions. The large heterochromatic blocks were found on chromosome no 6. Some of repetitive elements were scattered while some were specific in the karyotype. The combine of conventional banding and molecular cytogenetics provide information for a cytogenetic determination of the examined species.