Analysis of cloned PCR fragments from hybrid cells carrying parental A3243G and A4269G mtDNAs. Gene maps of human mtDNAs. Closed and open green arrowheads on the maps represent the forward primer (F) and reverse primer (R), respectively, used for amplification of 4,878-bp products (arcs). The cloned regions of 4,878-bp PCR products include the D loop and the pathogenic mutation sites of both parental A3243G and A4269G mtDNAs and are shown in pink and blue regions, respectively, on the gene maps. The corresponding region of the CRS (26) is shown in yellow.