Project description:Gene expression variation was measured in 17 non-laboratory strains compared to the sequenced S288c lab strain Keywords: Gene expression comparisons in different yeast strains
Project description:Recent advancements in genome sequencing have facilitated accessing the natural genetic diversity of species, unveiling hidden genetic traits, clarifying gene functions, and the degree to which laboratory studies can be generalized. One notable discovery is the frequent (~20%) aneuploidy - an imbalance in chromosome copy numbers - in natural Saccharomyces cerevisiae (Sc) isolates, despite the significant fitness costs and transient nature reported for lab-engineered yeast aneuploids. To examine this discrepancy, we adapted a high-throughput proteomic platform to analyze the proteome of 800 diverse yeast isolates. Matching these proteomes to the natural isolates’ genomes, transcriptomes, as well as generating ubiquitinome and protein turnover data for selected isolates, we report that natural and lab-generated aneuploids differ specifically at the proteome. While lab-generated aneuploids attenuate specific proteins – mostly protein complex subunits – and do not alter the average gene dosage provided by chromosome duplications, in natural strains, 70% of proteins encoded on aneuploid chromosomes are attenuated, and protein levels are shifted towards the euploid state chromosome-wide. Our data links chromosome-wide dosage compensation in natural strains to i) genome-wide buffering of gene expression changes manifesting in trans on euploid chromosomes, ii) increased expression of structural components of the ubiquitin proteasome system, and iii) increased global rates of protein turnover. Our results encourage the exploitation of natural diversity of species to understand complex biological processes at the molecular level. This submission contains the raw files for the disomics lab engineered strains, the library used for the analysis and the corresponding DIA-NN report and associated files.
2024-03-11 | PXD044526 | Pride
Project description:Genome sequences of Vibrio cholerae strains
Project description:The rapid pace of bacterial evolution enables organisms to adapt to the laboratory environment with repeated passage and thus diverge from naturally-occurring environmental (“wild”) strains. Distinguishing wild and laboratory strains is clearly important for biodefense and bioforensics; however, DNA sequence data alone has thus far not provided a clear signature, perhaps due to lack of understanding of how diverse genome changes lead to convergent phenotypes, difficulty in detecting certain types of mutations, or perhaps because some adaptive modifications are epigenetic. Monitoring protein abundance, a molecular measure of phenotype, can overcome some of these difficulties. We have assembled a collection of Yersinia pestis proteomics datasets from our own published and unpublished work, and from a proteomics data archive, and demonstrated that protein abundance data can clearly distinguish laboratory-adapted from wild. We developed a lasso logistic regression classifier that uses binary (presence/absence) or quantitative protein abundance measures to predict whether a sample is laboratory-adapted or wild that proved to be ~98% accurate, as judged by replicated 10-fold cross-validation. Protein features selected by the classifier accord well with our previous study of laboratory adaptation in Y. pestis. The input data was derived from a variety of unrelated experiments and contained significant confounding variables. We show that the classifier is robust with respect to these variables. The methodology is able to discover signatures for laboratory facility and culture medium that are largely independent of the signature of laboratory adaptation. Going beyond our previous laboratory evolution study, this work suggests that proteomic differences between laboratory-adapted and wild Y. pestis are general, potentially pointing to a process that could apply to other species as well. Additionally, we show that proteomics datasets (even archived data collected for different purposes) contain the information necessary to distinguish wild and laboratory samples. This work has clear applications in biomarker detection as well as biodefense.
Project description:Here, we investigate the genetic mechanisms that underlie thermal specialization of closely-related vibrios isolated from coastal water at the Beaufort Inlet (Beaufort, NC, USA). This location experiences large seasonal temperature fluctuations (annual range of ~20°C), and a clear seasonal shift in vibrio diversity has been observed (Yung et al. 2015). This previous study suggested that the mechanisms of thermal adaptation apparently differ based on evolutionary timescale: shifts in the temperature of maximal growth occur between deeply branching clades but the shape of the thermal performance curve changes on shorter time scales (Yung et al. 2015). The observed thermal specialization in vibrio populations over relatively short evolutionary time scales indicates that few genes or cellular processes may contribute to the differences in thermal performance between populations. In order to understand the molecular mechanisms that underlie adaptation to local thermal regimes in environmental vibrio populations, we employ genomic and transcriptomic approaches to examine transcriptomic changes that occur within strains grown at their thermal optima and under heat and cold stress. Moreover, we compare two closely-related strains with different laboratory thermal preferences to identify in situ evolutionary responses to different thermal environments in genome content and alleles as well as gene expression.
Project description:This is a study to compare the basal transcriptomes of several widely used laboratory strains of the Chlorophyte alga, Chlamydomonas reinhardtii. Given that there is a high degree of genetic diversity among the closely-related laboratory strains, we wished to examine how much variation there is at the transcriptome level. A panel of WT strains (CC-124, CC-125, CC-1009, CC-1690, CC-1691), all believed to be descended from a single zygospore isolated in 1945, were chosen based on their representing the oldest lineages among the standard laboratory strains. Additionally, CC-4532, which was the source for the current (v6) reference assembly, and CC-4533, which is the initial parental strain of the CLiP library collection of mutant strains, were also included in this study based on their significance to the Chlamydomonas community. All strains were grown in liquid cultures under identical, mixotrophic conditions (light + acetate) to mid-log phase before collecting mRNA for RNA-Seq analysis.
Project description:The Crabtree effect, in which fermentative metabolism is preferred at the expense of respiration, is a hallmark of budding yeast’s glucose response and a model for the Warburg effect in human tumors. While the glucose-responsive transcriptional repressors Mig1p and Mig2p play well-characterized roles in the Crabtree effect, little function for the related Mig3p transcription factor has been uncovered despite numerous investigations of laboratory yeast strains. Here we studied a wild isolate of Saccharomyces cerevisiae to uncover a critical role for Mig3p that has been lost in S288c-derived laboratory strains. We found that Mig3p affects the expression of hundreds of glucose-responsive genes in the oak strain YPS163, both during growth under standard conditions and upon ethanol treatment. Our results suggest that Mig3p may act as a multifunctional activator/repressor that plays separate roles under standard versus stress conditions, but this function has been largely lost in the lab strains. Population analysis suggests that the lab strain, and several wild strains, harbor mutations that diminish Mig3p function. Thus, by expanding our attention to multiple genetic backgrounds, we have uncovered an important missing link in a key metabolic response.
Project description:A microarray experimental design with dye balancing was adopted to compare the gene expression profiles of the following experimental groups; Field collected Makkah and Jeddah strains unexposed to any insecticide Fully insecticide susceptible New Orleans and Rockefeller laboratory strains. Laboratory Jeddah strain (F5) without exposure to insecticides Laboratory Jeddah strains selected for deltamethrin resistance (F5). For each comparison (field, lab selected or unselected vs susceptible), three biological replicates were used. The two susceptible strains, New Orleans and Rockefeller served as reference.
Project description:Helicobacter pylori, which is known as pathogens of various gastric diseases, have many types of genome sequence variants. That is part of the reason why pathogenesis and infection mechanisms of the H. pylori-driven gastric diseases have not been well clarified yet. Here we performed a large-scale proteome analysis to profile the heterogeneity of the proteome expression of 7 H. pylori strains by using LC/MS/MS-based proteomics approach combined with a customized database consisting of non-redundant tryptic peptide sequences derived from full genome sequences of 52 H. pylori strains. The non-redundant peptide database enabled us to identify more peptides in the database search of MS/MS data, compared with a simply merged protein database. Using the approach we performed proteome analysis of genome-unknown strains of H. pylori in as large-scale as genome-known ones. Clustering of the H. pylori strains using the proteome profiling slightly differed from the genome profiling and more clearly divided the strains into two groups based on the isolated area. Furthermore, we also identified phosphorylated proteins and sites of the H. pylori strains and obtained phosphorylation motif located in the N-terminus, which are commonly observed in bacteria.