Figure 5. Clonal expansion of mtDNA deletions in muscle.

Muscle sections of transgenic founders were stained for cytochrome oxidase activity and dissected by Laser Capture Microscopy. Panel A shows a nested PCR for the mtDNA deleted region breakpoint of representative COX-negative fiber segments. Positive reactions were cloned into plasmids and digested with EcoRI to release the insert (panel B). Sequencing reactions identified the deletion breakpoints, which were coded as in figure 4.