Makova mtDNA mutations macaque (IMAGE) Penn State Caption A new study shows that mutation frequencies in mitochondrial DNA are lower, and increase less with age, in the precursors of egg cells than in the cells of other tissues in a primate. Mitochondrial DNA was sequenced in liver, skeletal muscle, and single oocyte samples from 1- to 23-year-old rhesus macaques. New mutations increased with age the fastest in liver, and the slowest in oocytes. Mutation frequency in oocytes increased only until the age of 9 years. The light-strand origin of replication (OriL), the region responsible for copying the mitochondrial genomes, was found to be a hotspot of mutation accumulation with aging in liver. Credit Barbara Arbeithuber Usage Restrictions No restrictions License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.