Target analysis of mitochondrial genetic units in yeast.

Target analyses of the induction of rho(-) mutants indicated that the cytoplasm of an aerobic nonrepressed yeast contains approximately 20 mutable units, whereas repressed cells exhibit approximately 3. Aerobic adaptation of fully repressed cells brings about an increase in these cytoplasmic units which continues after maximal respiration has been reached. This increase can be correlated with the increase in numbers of stained mitochondria. The data are interpreted with reference to mitochondrial deoxyribonucleic acid.