A high resolution GBG-banded karyotype of the Atlantic bottlenose dolphin, Tursiops truncatus: generation of an ideogram, and NOR localization by fluorescence in situ hybridization

A high resolution karyotype was prepared using GBG-banded chromosomes from kidney epithelial cell lines of the Atlantic bottlenose dolphin, Tursiops truncatus. The karyotype was used to generate a banded ideogram of T. truncatus that will facilitate cytogenetic analyses essential for comparison of dolphin chromosomes with those of potentially related terrestrial vertebrates. Fluorescence in situ hybridization analysis of the karyotype using a rodent (Geomys bursarius) 28S ribosomal DNA (rDNA) probe allowed localization of four nucleolar organizer (NOR) regions to the short arms of two chromosome pairs. FISK mapping, using DNA probes, is dependent on a pre-existing banded ideogram, and provides the means to initiate physical mapping of the dolphin genome.