title: Tissue-specific and age-related variations in repetitive sequences of mouse extrachromosomal circular DNAs.
abstract: Extrachromosomal circular (ecc) DNA was isolated from mouse brain, liver, and heart tissues at different ages. To determine the abundance of repetitive sequences in eccDNAs, preparations were probed for short-interspersed (B1 and B2), long-interspersed (L1), endogenous retroviral-like (IAP), and tandemly repeated satellite sequences (SAT) of the mouse genome. Together these sequence families comprise approximately 15% of the mouse genome. The hybridization results showed that each tissue had a characteristic pattern of repetitive sequence elements in eccDNAs, and the abundance of repetitive sequences changed as a function of age. Repetitive sequences decreased in liver and brain eccDNAs from 1 month to 8 months of age but appeared to remain stable thereafter. In contrast, repetitive sequence families in heart eccDNAs were constant from 1 month to 16 months of age but declined in 24-month-old mice. The present studies indicate that extrachromosomal sequences exhibit greater flexibility than chromosomal sequences.
authors.affiliation: Department of Biochemistry, University of South Alabama, College of Medicine, Mobile 36688.
authors.forename: J W
authors.initials: JW
authors.lastname: Gaubatz
authors.forename: S C
authors.initials: SC
authors.lastname: Flores
mesh_terms: D000375:Aging / Q000235:genetics*; D000818:Animals; D001921:Brain / Q000378:metabolism; D015342:DNA Probes; D004270:DNA, Circular / Q000235:genetics* / Q000302:isolation & purification; D004276:DNA, Satellite / Q000235:genetics* / Q000302:isolation & purification; D015151:Immunoblotting; D008099:Liver / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009206:Myocardium / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics*
chemical_list: D015342:DNA Probes; D004270:DNA, Circular; D004276:DNA, Satellite