Banded Karyotypes of Six Taxa of Kinosternid Turtles

Sites, Jack; Bickham, John; Haiduk, Mike; Iverson, John

C- and G-banding analyses were performed on representatives of three genera of kinosternid turtles (Kinosternon, Sternotheurs, Staurotypus), representing both subfamilies and all known chromosomal variation in the family. Those species C-banded showed that constitutive heterochromatin was restricted to the centromeric regions of the chromosomes, but the number of pairs having heterochromatic regions differed among species. Species of Kinosternon from the southeastern United States were more similar to Sternotherus in the amount and distribution of heterochromatin than they were to Kinosternon from Mexico. G-band data showed that chromosomal change has been minimal since the divergence of the three genera. Banding patterns are distinctive for most macrochromosomes of each species, and almost all homologous arms can be identified among the three genera. We conclude that the karyotype characteristic of kinosternine turtles was derived from the Staurotypus karyotype by a pericentric inversion in the second largest chromosome pair and by a fission in one pair of group B chromosomes. This accounts for the differences in chromosome morphology and diploid number between the two subfamilies.

Banded Karyotypes of Six Taxa of Kinosternid Turtles

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