Tissue-specific and age-related variations in repetitive sequences of mouse extrachromosomal circular DNAs.
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.
Gaubatz
J W
JW
Department of Biochemistry, University of South Alabama, College of Medicine, Mobile 36688.
Flores
S C
SC
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*
D015342:DNA Probes; D004270:DNA, Circular; D004276:DNA, Satellite