A simple method for isolating disomic strains of Saccharomyces cerevisiae.

A simple method to select disomic (N + 1) strains that should be applicable for almost any chromosome in Saccharomyces cerevisiae is presented. A diploid heterozygous for a KanMX knock-out mutation in an essential gene is sporulated and viable geneticin (G418)-resistant colonies selected. Disomic products of a missegregation or non-disjunction event containing a copy of both the wild-type essential gene and its complementary KanMX knock-out allele make up most of the viable colonies. This method has been used to isolate disomic haploids for a variety of chromosomes. It is appropriately named MARV (for missegregation-associated restoration of viability) and is easily adaptable to virtually any strain.