title: Extrachromosomal circular DNA and aging cells.
abstract: A DNA sequence situated in the human genome between Alu-repeat clusters ("Inter-Alu" DNA) is progressively amplified in extrachromosomal DNA, including covalently closed DNA circles, during serial passage of diploid fibroblasts. A single size-class of Inter-Alu circles is also amplified in lymphocytes from 16 of 24 old donors and yet is not detected in cells from 18 young donors.
mesh_terms: D002470:Cell Survival; D002877:Chromosomes, Human; D004251:DNA Transposable Elements; D004270:DNA, Circular / Q000032:analysis*; D005347:Fibroblasts / Q000737:chemistry; D005784:Gene Amplification; D006801:Humans; D066298:In Vitro Techniques; D008214:Lymphocytes / Q000737:chemistry; D012091:Repetitive Sequences, Nucleic Acid
chemical_list: D004251:DNA Transposable Elements; D004270:DNA, Circular