Qualitative and quantitative analysis of the ND6 frameshift (13885insC) and ND6 revertant (13885insCdelT) mutations in mouse ES cell cybrids and tissues of F1 female EC77-AG. (A) Sequence around nucleotide 13,885 of two clones of mtDNA from EC77 cells. Top (13885insC), the single C insertion causing the frameshift (asterisk); bottom (13885insCdelT), the T (arrow) deletion that restored the normal reading frame. (B) Percentages of ND6 frameshift (13885insC, blue) versus revertant (13885insCdelT, purple) in four independent mouse ES cybrids. (C) Proportions of ND6 frameshift (13885insC) and revertant (13885insCdelT) mtDNAs in the tissues of F1 female EC77-AG.