Human cell mutants with very low mitochondrial DNA copy number (ρd)

Abstract

Mutants of human Namalwa cells are described, denoted ρd (mtDNA-depleted), which contain a very low mtDNA copy number. Three isolates, denoted FV02, FV03 and FV05, each selected on the basis of their pyruvate-dependent phenotype, were shown to have severely reduced mitochondrial respiratory functions consistent with results of histochemical and cytochrome analysis. Analyses of mtDNA by the polymerase chain reaction (PCR) and Southern blotting indicated that FV02, Fy03 and FV05 each contained a full complement of mtDNA sequences, 16.6 kb in length, in circular form but at a greatly reduced level compared with that of parent ρ+ cells. Quantitative PCR tests showed first, that the parent Namalw..