Behavioral and metabolic characterization of heterozygous and homozygous POLG mutator mice

Mitochondrion. 2013 Jul;13(4):282-91. doi: 10.1016/j.mito.2013.03.006. Epub 2013 Mar 27.


The mitochondrial DNA (mtDNA) polymerase γ (POLG) mutator mice provide the first experimental evidence that high levels of somatic mtDNA mutations can be functionally significant. Here we report that older homozygous, but not heterozygous, POLG mice show significant reductions in striatal dopaminergic terminals as well as deficits in motor function. However, resting oxygen consumption, heat production, mtDNA content and mitochondrial electron transport chain activities are significantly decreased at older ages in both homozygous and heterozygous mice. These results indicate that high levels of somatic mtDNA mutations can contribute to dopaminergic dysfunction and to behavioral and metabolic deficits.

MeSH terms

  • Animals
  • DNA Polymerase gamma
  • DNA, Mitochondrial / metabolism*
  • DNA-Directed DNA Polymerase / genetics*
  • DNA-Directed DNA Polymerase / metabolism*
  • Gait Disorders, Neurologic
  • Heterozygote
  • Homozygote
  • Hot Temperature
  • Mice
  • Mitochondria / enzymology*
  • Mitochondria / metabolism*
  • Mutation*
  • Oxygen Consumption
  • Visual Cortex / pathology


  • DNA, Mitochondrial
  • DNA Polymerase gamma
  • DNA-Directed DNA Polymerase
  • Polg protein, mouse