(a) MtDNA mutation load was determined in heterozygous D263A flies
in different developmental stages. The D263A exo- allele was transmitted
paternally and therefore all the detected mutations are produced by somatic
mutagenesis. An increase in the mtDNA mutation load relative to wild-type (WT)
flies was only detected after morphogenesis. One-way ANOVA with Dunnett’s
post hoc test. ***p<0.001, ** p<0.01, *p<0.05. Error bars
represent S.D. n=3-6.
(b) MtDNA mutations accumulated in heterozygous D263A exo- flies
after successive intercrossing for several generations. MtDNA mutation loads
were compared among wild-type flies (WT, white bar), heterozygous D263A exo-
flies with a clean background (+/D263A, lack maternally transmitted mtDNA
mutations, grey bar) and heterozygous D263A exo- flies that maternally inherited
mtDNA mutations for 1, 4, 6 or 13-15 generations (D263A/+, black bar). One-way
ANOVA with Dunnett’s post hoc test. ***p<0.001, ** p<0.01,
*p<0.05. Error bars represent S.D. n=3-6.