Figure 1.
Figure 1. Phylogenetic tree of haplogroup H and T subsets.
The phylogenetic tree was constructed according to phylotree.org [32]. aC16296T did not appear in the mtDNA sequence of cybrid T1. bBases of the Revised Cambridge Reference Sequence that appear in HEK T cybrids as polymorphisms diagnostic for non-H haplogroups (m.73A>G, m.2706A>G, m.7028C>T, m.11719G>A and m.14766C>T).
Table 1.
Enzymatic activities of citrate synthase and oxidative phosphorylation complexes I – V in haplogroup H and T cybrid cells.
Figure 2.
Mitochondrial DNA copy number in cybrid cells.
(A) Comparison of all cybrid clones cultivated in glucose medium and galactose medium. (B) Comparison of HEK H and HEK T cybrids cultivated in glucose medium. (C) Comparison of HEK H and HEK T cybrids cultivated in galactose medium. Mean values of copy numbers are given; error bars: standard deviation; *p<0.05.
Figure 3.
Growth curves of mitochondrial haplogroup-specific cybrid cells.
The number of cells on the days given were normalized to the number of cells on day two and determined as growth rate. (A) Comparison of HEK H (n = 3; gray circles) and HEK T (n = 3; black squares) cybrids at days three to seven in glucose medium. (B) Comparison of HEK H (n = 3; gray circles) and HEK T (n = 3; black squares) cybrids at days three to seven in galactose medium. Mean values of growth rates are given; error bars: standard deviation; *p<0.05.
Figure 4.
Results of TaqMan qPCR analysis of HEK H and HEK T cybrid competitive co-cultures.
After 10, 20 and 30 days (d10, d20, d30) of co-culture, isolated DNA of the cell mixtures was analyzed using TaqMan qPCR. ΔCt values were calculated by subtraction of the mean Ct value of the FAM signal (probe recognizing haplogroup T) from the mean Ct value of the VIC signal (probe recognizing haplogroup H). ΔΔCt values were calculated by subtraction of the mean ΔCt values of the original cell mixtures (n = 36; day zero) from the mean ΔCt values of all co-cultures at days 10, 20 or 30 (n = 36; except for d30 in galactose: n = 35). Dominance of haplogroup H results in a negative ΔΔCt value and is presented as gray bars, whereas dominance of haplogroup T results in a positive ΔΔCt value and is presented as black bars. (A) ΔΔCt values of competitive co-cultures cultivated in glucose medium, at days 10, 20 and 30. (B) ΔΔCt values of competitive co-cultures cultivated in galactose medium, at days 10, 20 and 30. Mean ΔΔCt values are given; error bars: standard deviation.
Figure 5.
Cell survival after treatment with H2O2.
Cell survival was measured 24 hours after H2O2 treatment and calculated as a percentage of the ratio between treated and untreated cells (% cell survival). (A) Comparison of HEK H (n = 3; gray bars) and HEK T (n = 3; black bars) cybrids at 250 µM to 475 µM H2O2 in glucose medium without serum and without sodium pyruvate. (B) Comparison of HEK H (n = 3; gray bars) and HEK T (n = 3; black bars) cybrids at 100 µM to 250 µM H2O2 in galactose medium without serum and without sodium pyruvate. Mean values of % cell survival are given; error bars: standard deviation; *p<0.05.