Selective loss of ribosomal RNA genes during the aging of post-mitotic tissues

摘要: Abstract Maintenance of long-term genetic integrity in living cells is facilitated by a combination enzymatic repair mechanisms and cellular selection processes. In dividing cell populations, tissues comprised cells, defective can be continuously replaced through the selective propagation most viable cells. However, many important organs higher animals are non-dividing (post-mitotic) which such processes not operate. It was interest, therefore, to investigate possibility damage as factor age-dependent deterioration observed key post-mitotic nervous muscular system. The technique RNA·DNA molecular hybridization used measure dosage ribosomal RNA genes selected mitotic aging beagle dogs. This approach chosen both because importance these protein synthesis order test previously proposedmodel for loss tandemly duplicated during aging. results indicate substantial decline number cistrons DNA from brain, heart skeletal muscle 10-year-old These findings proposed model discussed relation other studies changes possible effects gene on function.