To see whether point mutations, which affect just one DNA base in mtDNA, are directly involved in aging, a team of researchers at the University of Washington in Seattle charted mtDNA mutation
frequency in normal mice and «mitochondrial mutator» mice.
Scientists compared urination patterns, both volume and
frequency,
in normal mice and
in mice genetically engineered without two circadian genes, Cryptochrome - 1 and Cryptochrome - 2, resulting
in dysfunctional circadian rhythms.