A point mutation in the mitochondrial DNA of diabetes-prone BHE/cdb rats.

Mitochondrial DNA was extracted from hepatic tissue of 50- and 300-day-old male BHE/cdb and Sprague-Dawley rats. The complete gene for the F0ATPase subunits 6 and 8 was sequenced. Four nucleotide substitutions were found: three of the substitutions were silent; the other substitution at position 523 was not. Its codon dictates the substitution of asparagine for aspartic acid in a critical location (in the polar pocket) of the F0ATPase. It is possible that this point mutation may explain previously reported decreases in ATP synthesis efficiency in BHE/cdb rats compared to Sprague-Dawley rats.