Construction of a yeast strain deleted for the TRP1 promoter and coding region that enhances the efficiency of the polymerase chain reaction-disruption method.

The sequence of the genome of Saccharomyces cerevisiae was recently determined. As well as all the informations concerning the structure of the chromosomes the scientific community had to deal with the discovery of dozens of new open reading frames (ORFs) of unknown function. The study of these ORFs requires the development of simple procedures that can be used on a large scale. In the framework of a European Pilot Project we have described a new approach for deleting ORFs. This method is based on transformation with a polymerase chain reaction product but is limited by the use of a strain deleted for the auxotropic marker. We present here the construction of a new recipient strain that lacks the TRP1 region and that allows a high efficiency of gene deletion.