REVIEW - THE DOMINANT FLOCCULATION GENES OF SACCHAROMYCES-CEREVISIAE CONSTITUTE A NEW SUBTELOMERIC GENE FAMILY

The quality of brewing strains is, in large part, determined by their flocculation properties. By classical genetics, several dominant, semi dominant and recessive flocculation genes have been recognized. Recent results of experiments to localize the flocculation genes FL05 and FL 08, combined with the in silicio analysis of the available sequence da ta of the yeast genome, have revealed that the flocculation genes belo ng to a family which comprises at least four genes and three pseudogen es. All members of this gene family are located near the end of chromo somes, just like the SUC, MEL and MAL genes, which are also important for good quality baking or brewing strains. Transcription of the flocc ulation genes is repressed by several regulatory genes. In addition, a number of genes have been found which cause cell aggregation upon dis ruption or overexpression in an as yet unknown manner. In total, 33 ge nes have been reported that are involved in flocculation or cell aggre gation.