The Karyotype of Salvator merianae (Squamata, Teiidae): Analyses by Classical and Molecular Cytogenetic Techniques

Abstract

In this study, we analyzed the karyotype of Salvator merianae (Teiidae) from the Brazilian semiarid region using different cytogenetic markers. Chromosomes were examined by classical (Giemsa and AgNOR staining) and molecular (FISH with ribosomal, telomeric, and microsatellite probes) cytogenetic approaches. S. merianae showed a diploid chromosome number of 2n = 38 (10 biarmed macrochromosomes + 28 microchromosomes). No sex-linked chromosome heteromorphisms were observed. Clusters of 18S/28S rDNA were localized in the terminal region of the long arm of pair 2. In addition to the typical telomeric signals, (TTAGGG)n repeats were detected in the pericentromeric region of some macrochromosome pairs, which might indicate the occurrence of chromosomal rearrangements via chromosome fusions. Hybridization signals of the microsatellite probes (GA)n, (GAA)n, and (GAG)n were uniformly distributed across all chromosomes, while (CA)n, (CAA)n, and (CAC)n produced brighter signals in the telomeric and pericentromeric regions of specific chromosome pairs. The comparison with previous studies demonstrates that, despite the wide distribution of S. merianae, the macrostructure organization of the karyotype remained unchanged, showing stability in diploid number and chromosome morphology.