A SIMPLE PCR METHOD FOR DISTINGUISHING SACCHAROMYCES-CEREVISIAE FROM ITS SIBLING SPECIES BY AMPLIFICATION OF THE RPL2 REGION

A simple polymerase chain reaction (PCR) method for identification of the four species of Saccharomyces sensu stricto was developed. The met hod is based on amplification of the RPL2 region using three primers d esigned to detect the structural differences between the RPL2 flanking regions of S. cerevisiae and S. bayanus. A 1.1-kb DNA fragment was am plified in both S. cerevisiae and S. paradoxus, although the amount of amplified DNA in S. paradoxus was small compared to that in S. cerevi siae. A 1.9-kb DNA fragment was amplified specifically in S. bayanus. Both 1.1-kb and 1.9-kb DNA fragments were amplified in S. pastorianus, which is thought to be a hybrid species of S. cerevisiae and S. bayan us. Thus, using the three primers, the four species of Saccharomyces s ensu stricto could be easily distinguished by the size and amount of t he PCR product.