Generation of null alleles for the functional analysis of six genes from the right arm of Saccharomyces cerevisiae chromosome II

Using PCR-ligated long flanking homology cassettes: null alleles of six ope n reading frames (ORFs) from chromosome II have been created in Saccharomyc es cerevisiae. Deletants were constructed in three genetic backgrounds: FY1 679, W303 and CEN.PK2. Tetrad analysis of heterozygous deletants revealed t hat none of the ORFs is essential for vegetative growth. Basic phenotypic a nalysis of haploid deletants showed that deletion of the YBR283e ORF causes a slight growth defect at 30 degrees C and 37 degrees C on glycerol-comple te, glucose-complete, and glucose-minimal media only in the FY1679 and W303 backgrounds. Transformation of these deletants with the corresponding cogn ate gene in a centromeric plasmid complements the defects. Deletion of the YBR287w ORF leads to poor growth on glucose-minimal medium at 15 degrees C in the FY1679 background. None of the six ORFs seems to be involved in mati ng or sporulation. Copyright (C) 1999 John Wiley & Sons, Ltd.