Life Sciences Institute, University of Michigan, Ann Arbor, United States; Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, United States; Medical Scientist Training Program, University of Michigan, Ann Arbor, United States
Life Sciences Institute, University of Michigan, Ann Arbor, United States; Howard Hughes Medical Institute, University of Michigan, Ann Arbor, United States
Life Sciences Institute, University of Michigan, Ann Arbor, United States; Howard Hughes Medical Institute, University of Michigan, Ann Arbor, United States
Life Sciences Institute, University of Michigan, Ann Arbor, United States; Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, United States
Life Sciences Institute, University of Michigan, Ann Arbor, United States; Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, United States; Howard Hughes Medical Institute, University of Michigan, Ann Arbor, United States; Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, United States
rDNA loci, composed of hundreds of tandemly duplicated arrays of rRNA genes, are known to be among the most unstable genetic elements due to their repetitive nature. rDNA instability underlies aging (replicative senescence) in yeast cells, however, its contribution to the aging of multicellular organisms is poorly understood. In this study, we investigate the dynamics of rDNA loci during aging in the Drosophila male germline stem cell (GSC) lineage, and show that rDNA copy number decreases during aging. Our study further reveals that this age-dependent decrease in rDNA copy number is heritable from generation to generation, yet GSCs in young animals that inherited reduced rDNA copy number are capable of recovering normal rDNA copy number. Based on these findings, we propose that rDNA loci are dynamic genetic elements, where rDNA copy number changes dynamically yet is maintained through a recovery mechanism in the germline.
