Disruption and basic phenotypic analysis of 18 novel genes from the yeast Saccharomyces cerevisiae

In the frame of the European Network for Functional Analysis (EUROFAN) we h ave deleted 18 yeast open reading frames (ORFs) from chromosomes II, X and XIV using the short flanking homology-PCR strategy. Two diploid strains wer e used: FY1679 and CEN.PK2. The deletion kanMX6 cassettes with long flankin g homology and the cognate gene clones have also been constructed. Heterozy gous diploid deletant strains have been sporulated. Tetrad analysis reveale d that an the ORFs studied were non-essential. However, four deletant strai ns exhibited phenotypes. The YBL025w Delta strain showed extremely slow cel lular growth under all conditions tested. The YJL204c Delta strain grew slo wer than wild-type at 30 degrees C and 37 degrees C. was cold-sensitive, an d the homozygous diploids did not sporulate. The YNL213c Delta strain did n ot grow on glycerol and had lost mitochondrial DNA. The deletion of YNL215w caused slower growth on all media but the defect was more pronounced on gl ucose-minimal and glycerol-rich media than on glucose-rich medium. All dele tion mutants were complemented by the corresponding plasmid borne cognate g ene. The YJL204w, YNL213c and YNL215w ORFs do not bear significant homology to proteins of known function. YBL025w has recently been identified as RRN 10, a gene that encodes an RNA polymerase I-specific transcription initiato r factor. The deletion of the remaining fourteen ORFs did not reveal any mu tant phenotype in our basic growth tests. Copyright (C) 1999 John Wiley & S ons, Ltd.