What Happens to the MtDNA of Mice That Are Homozygous

Essay

What happens to the mtDNA of mice that are homozygous for the mutant gene called Polg? How do the "mutator" mice differ from their normal littermates? How do mice that are heterozygous for the Polg mutation differ from those that are homozygous for the Polg mutation? What should have happened to the life span of mice heterozygous for the Polg gene,if mtDNA mutations were a major contributor to the normal aging process? What do the above results of studies of the Polg mutation suggest about the relationship between mtDNA mutations and premature aging in animals?