Saccharomyces cerevisiae strain XS-380, a. heteroallelic
diploid strain, carries six genetically analyzed loci on the left arm of
chromosome VII. Nitrosoguanidine (NMG) at low concentrations was
observed to cause allelic recombination (either mitotic recombination
or gene conversion) of the heteroallelic loci with low lethality.
The NMG-inducible heteroallelic system was used...