Contrasting denaturation maps of Xenopus laevis and Xenopus borealis mitochondrial DNAs.

Denaturation maps of mitochondrial DNAs of Xenopus laevis and Xenopus borealis are radically different from each other. This is in striking contrast to the invariant denaturation patterns previously recognized among mtDNAs of various Drosophila species, particularly, since the two toads may be even more closely related to each other than the Drosophila species.