Project description:Wine biological aging is a wine making process used to produce specific beverages in several countries in Europe, including Spain, Italy, France, and Hungary. This process involves the formation of a velum at the surface of the wine. Here, we present the first large scale comparison of all European flor strains involved in this process. We inferred the population structure of these European flor strains from their microsatellite genotype diversity and analyzed their ploidy. We show that almost all of these flor strains belong to the same cluster and are diploid, except for a few Spanish strains. Comparison of the array hybridization profile of six flor strains originating from these four countries, with that of three wine strains did not reveal any large segmental amplification. Nonetheless, some genes, including YKL221W/MCH2 and YKL222C, were amplified in the genome of four out of six flor strains. Finally, we correlated ICR1 ncRNA and FLO11 polymorphisms with flor yeast population structure, and associate the presence of wild type ICR1 and a long Flo11p with thin velum formation in a cluster of Jura strains. These results provide new insight into the diversity of flor yeast and show that combinations of different adaptive changes can lead to an increase of hydrophobicity and affect velum formation.
Project description:In response to limited nitrogen and abundant carbon sources, diploid Saccharomyces cerevisiae strains undergo a filamentous transition in cell growth as part of pseudohyphal differentiation. Use of the disaccharide maltose as the principal carbon source, in contrast to the preferred nutrient monosaccharide glucose, has been shown to induce a hyper-filamentous growth phenotype in a strain deficient for GPA2 which codes for a Gï¡ protein component that interacts with the glucose-sensing receptor Gpr1p to regulate filamentous growth. In this report, we compare the global transcript and proteomic profiles of wild-type and Gpa2p deficient diploid yeast strains grown on both rich and nitrogen starved maltose media. We find that deletion of GPA2 results in significantly different transcript and protein profiles when switching from rich to nitrogen starvation media. The results are discussed with a focus on the genes associated with carbon utilization, or regulation thereof, and a model for the contribution of carbon sensing/metabolism-based signal transduction to pseudohyphal differentiation is proposed. Experiment Overall Design: For transcriptome profiling, there were 12 Affymetrix Yeast S98 microarrays total. There were four conditions: wildtype MLY61 and gpa2 deletion mutant MLY132 grown in YPM media or transferred to low nitrogen media SLAM. Each condition was done in triplicate, starting with triplicate yeast cultures. Four conditions done in triplicates resulted in 12 samples that went onto 12 microarrays.
Project description:Growth assay in the presence of a toxic chemical (sr7575) that uses the barcoded collections of yeast gene deletions (haploid, diploid, DamP) to identify deletion strains that are hypersensitive to the drug.
Project description:In response to limited nitrogen and abundant carbon sources, diploid Saccharomyces cerevisiae strains undergo a filamentous transition in cell growth as part of pseudohyphal differentiation. Use of the disaccharide maltose as the principal carbon source, in contrast to the preferred nutrient monosaccharide glucose, has been shown to induce a hyper-filamentous growth phenotype in a strain deficient for GPA2 which codes for a Galpha protein component that interacts with the glucose-sensing receptor Gpr1p to regulate filamentous growth. In this report, we compare the global transcript and proteomic profiles of wild-type and Gpa2p deficient diploid yeast strains grown on both rich and nitrogen starved maltose media. We find that deletion of GPA2 results in significantly different transcript and protein profiles when switching from rich to nitrogen starvation media. The results are discussed with a focus on the genes associated with carbon utilization, or regulation thereof, and a model for the contribution of carbon sensing/metabolism-based signal transduction to pseudohyphal differentiation is proposed. Keywords: Saccharomyces cerevisiae, nitrogen starvation, maltose, pseudohyphal differentiation, yeast, expression profiling
Project description:Growth assay in the presence of a toxic chemical that uses the barcoded collections of yeast gene deletions (haploid, diploid, DamP) to identify deletion strains that are hypersensitive to the drug.
Project description:Six strains of Saccharomyces cerevisiae were grown in four different environments representing a continuum of rich and poor natural conditions Keywords: Stress response, genetic diversity
Project description:Purpose: The goal of this study was to globally characterize the transcript levels of genes in Saccharomyces cerevisiae WT and set4∆ strains during hypoxia. Using transcriptome profiling of isogenic WT and set4∆ strains grown under aerobic or 8 hours of hypoxia. We analyzed the changes in gene expression that occur during aerobic and hypoxic conditions and identified sets of upregulated and downregulated gene expression.
Project description:We investigated the effects of the ploidy on cellular response in strains carrying various types of gross chromosomal rearrangements. Fourteen mutated strains (6 haploid strains and 8 diploid strains) were compared to their associated parental strain (haploid or diploid parental strain). For each comparison, 2 microarray experiments implying biological replicates were performed.
Project description:This study explores the connection between changes in gene expression and the genes that determine strain survival during suspension culture, using the model eukaryotic organism, Saccharomyces cerevisiae. The Saccharomyces cerevisiae homozygous diploid deletion pool, and the BY4743 parental strain were grown for 18 hours in a rotating wall vessel, a suspension culture device optimized to minimize the delivered shear. In addition to the reduced shear conditions, the rotating wall vessels were also placed in a static position or in a shaker in order to change the amount of shear stress on the cells. Keywords: shear stress, time course
Project description:Saccharomyces cerevisiae cells have evolved remarkably sophisticated and flexible transcriptional regulatory networks (TRNs) that allow them to survive and thrive in stress conditions, such as high temperature, osmotic and oxidative conditions, etc. Furthermore, transcription factor plays a central role in transcriptional regulatory networks of stress response. To achieve a thorough understanding of master transcription factors and transcriptional regulatory networks in specific response to prolonged thermal stress, we sequenced mRNA from the cultures of the wild type strain ScY01a as well as four key transcription factor deletion strains including ScY01a (ric1∆), ScY01a (srb2∆), ScY01a (sin3∆) and ScY01a (mig1∆) grown at 40ºC in biological duplicates. Differences in gene expression comparing the transcription factor deletion strains with the wild type strain by RNA deep sequencing revealed a hierarchical transcriptional regulatory network required for long-term thermal stress tolerance of S. cerevisiae, which is centered on these four transcription factors.