A NEW EFFICIENT GENE DISRUPTION CASSETTE FOR REPEATED USE IN BUDDING YEAST

The dominant kan(r) marker gene plays an important role in gene disrup tion experiments in budding yeast, as this marker can be used in a var iety of yeast strains lacking the conventional yeast markers. We have developed a loxP-kanMX-loxP gene disruption cassette, which combines t he advantages of the heterologous kan(r) marker with those from the Cr e-lox P recombination system. This disruption cassette integrates with high efficiency via homologous integration at the correct genomic loc us (routinely 70%). Upon expression of the Cre recombinase the kanMX m odule is excised by an efficient recombination between the loxP sites, leaving behind a single loxP site at the chromosomal locus. This syst em allows repeated use of the kan(r) marker gene and will be of great advantage for the functional analysis of gene families.