Temperature-sensitive respiratory-deficient mitochondrial mutations: isolation and genetic mapping.

In order to find new genetic loci and functions on the yeast mitochondrial DNA, especially mutations affecting the mitochondrial protein synthesis apparatus, temperature sensitive mutants have been isolated after MnCl2 mutagenesis and mitochondrial and nuclear mutants classified according to their pattern of recombination with three rho- tester strains. Eighteen cold- and heat-sensitive respiratory deficient mitochondrial mutants have been isolated and localized on the mitochondrial genome by deletion mapping using 113 rho- strains. Eight of them appear to represent new loci, among which some are probably mutations of the tRNA and rRNA genes.