Amplification of extrachromosomal small circular DNAs in a murine model of accelerated senescence. A brief note

Extrachromosomal circular DNA complexes from peripheral blood lymphocytes from inbred mice of accelerated senescence, were detected by mica-press-adsorption method. In senescence-resistant series (SAM-R), polydisperse circular DNAs were observed at 7 weeks of age and a restricted size class of small circular forms of 0.4-0.8 microns in contour length was amplified several-fold at 26 months of age. In senescence-prone series (SAM-P), a similar amplification of small circular DNAs was observed at young age of 10 weeks and more progressive at 17 months of age.