Amplification of inter-Alu extrachromosomal DNA during cellular ageing: retraction and explanation.
We reported previously the age-dependent appearance of extrachromosomal circular DNA bands hybridizing to a human DNA fragment ('inter-Alu'), isolated from a genomic cluster of AluI repeats. Such bands appeared or increased at late passage in four out of six human fibroblast strains (six out of nine cell expansions); moreover, all DNAs (9/9) obtained from peripheral lymphocytes of aged donors, but none (0/8) from young donors, revealed a non-genomic inter-Alu band at congruent to 4.8 kilobases (kb). Subsequent data extended these numbers to 16/24 aged donors compared with 0/18 young donors. These results were interpreted as evidence of age-dependent DNA rearrangement in normal human cells. We now report that the 'extra' bands were of microbial origin, although clearly occurring in an age-dependent manner.
Shmookler Reis
R J
RJ
Lumpkin
C K
CK
McGill
J R
JR
Riabowol
K T
KT
Goldstein
S
S
D000368:Aged; D002470:Cell Survival; D002478:Cells, Cultured; D004262:DNA Restriction Enzymes; D004270:DNA, Circular; D015252:Deoxyribonucleases, Type II Site-Specific; D006801:Humans; D009693:Nucleic Acid Hybridization; D010957:Plasmids
D004270:DNA, Circular; D004262:DNA Restriction Enzymes; C024669:endodeoxyribonuclease AluI; D015252:Deoxyribonucleases, Type II Site-Specific