An ethidium bromide induced mutant of Neurospora crassa defective in mitochondrial DNA

Slow growing mutants of Neurospora crassa were obtained by ethidium bromide treatment of the wild type strain. A particular mutant ER-3 showed stopper phenotype accompanied by deficient cytochrome spectra. The mutant showed an altered restriction pattern of the mtDNA which indicated a deletion of 25,000 bp. The phenotype of the ethidium bromide induced mutant ER-3 seem to be related to the loss of several essential genes due to a deletion in its mtDNA.