Figure 3.

Point mutant mtDNA heteroplasmy fluctuations after induced mtDNA depletion. Four cell lines harboring two different pathogenic mtDNA point mutations in tRNA genes were subjected to a 15 day EtBr treatment followed by a 30 day recovery period. Parallel cultures growing in the same medium, but without EtBr were performed to assess heteroplasmy fluctuations during time in culture. Total DNA was extracted at different times and analyzed by PCR/RFLP. The percentage mutated mtDNA is represented as filled circles in the EtBr treated series and as open circles in the control series (A–D). With the exception of one cell line (B), the percentage of point mutated mtDNA either did not change significantly or decreased from pretreatment levels. The treatment with EtBr did not seem to alter this natural trend.