Universal donor yeast strain for transfer of genetic material

Genetic Material Transfer with Universal Donor Strain High-efficiency transfer extrachromosomal genetic material such as plasmid DNA into any Saccharomyces strain for use with the current gene disruption libraries is described. The yeast cell comprises of chromosomes I through XVI, at least two of which comprise a nucleic acid sequence encoding a counterselectable marker linked to a centromere. The method of transfer comprises mating a recipient cell to a donor yeast cell wherein the donor cell comprises a mutation in the karyogamy pathway. The recipient cells which have acquired the extrachromosomal genetic material are selected through screening. The universal donor strain and the method are used in screening yeast gene disruption libraries with plasmid-based dominant negative alleles of various genes.