Chromosome Engineering in Yeast with a Site-Specific Recombination System from a Heterologous Yeast Plasmid

The targeted deletion or inversion of a large chromosomal segment and targeted recombination between two nonhomologous chromosomes can be created in Saccharomyces cerevisiae by using the site-specific recombination system from a heterologous yeast plasmid (1 ). The method consists of the insertion of specific recombination sites from a yeast plasmid with the aid of a yeast integrative vector (YIp) and the introduction of another plasmid carrying the gene for the corresponding site-specific recombination enzyme. This enzyme is stringently regulated by an inducible promoter. When cells are grown under inducing conditions, the site-specific recombination enzyme is produced, stimulating recombination between the two specific recombination sites, and creating a modified chromosome(s).