Project description:Combinatorial promoter expression level estimation via cell sorting The purpose of this experiment was to determine the expression level of a library of synthetic promoters. The promoters were cloned in front of a GFP reporter and the resulting library transformed into yeast, sorted by FACS into six fluorescence bins, and the contents of the bins sequenced to determine the distribution of each promoter among each fluorescence bin. This was then used to calculate an expression level for each promoter with enough data.
Project description:Combinatorial promoter expression level estimation via cell sorting The purpose of this experiment was to determine the expression level of a library of synthetic promoters. The promoters were cloned in front of a GFP reporter and the resulting library transformed into yeast, sorted by FACS into six fluorescence bins, and the contents of the bins sequenced to determine the distribution of each promoter among each fluorescence bin. This was then used to calculate an expression level for each promoter with enough data. The promoters were sorted into six bins and these, along with the unsorted library were barcoded and sequenced on a single lane of an Illumina HiSeq. The following Series supplementary files are provided: allPromoters.fsa.txt: the sequences of the promoters corresponding to the names in allPromoters.txt, not actually fasta format. Promoter sequence starts at pos 155 (0 indexed). allPromoters.txt: the names of all the promoters, corresponding to the sequences in allPromoters.fsa.txt barcodes.txt: the sequncing barcodes, corresponding to read2 from the sequencing files.
Project description:We designed and synthesized synI, which is ~21.4% shorter than native chrI, the smallest chromosome in Saccharomyces cerevisiae. SynI was designed for attachment to another synthetic chromosome due to concerns surrounding potential instability and karyotype imbalance, and is now attached to synIII, yielding the first synthetic yeast fusion chromosome. We constructed additional fusion chromosomes to investigate effects of fusions on nuclear function. We observed unexpected loops and twisted structures in chrIII-I and chrIX-III-I fusion chromosomes dependent on silencing protein Sir3. ChrI faces special challenges in assuring meiotic crossovers required for efficient homolog disjunction. Centromere deletions engineered into fusion chromosomes revealed opposing effects of core centromeres and pericentromeres in modulating deposition of meiotic recombination protein Red1. These effects extended over >100kb, to disproportionally promote meiotic recombination of small chromosomes like chrI. These findings reveal the power of synthetic genomics to uncover new biology and deconvolute complex biological systems.
Project description:Glycerol offers several advantages as a substrate for biotechnological applications. An important step towards using the popular production host Saccharomyces cerevisiae for glycerol-based bioprocesses have been recent studies in which commonly used S. cerevisiae strains were engineered to grow in synthetic medium containing glycerol as the sole carbon source. In order to boost extensive S. cerevisiae metabolic engineering incentives aiming at the use of glycerol, we realized that promoters with predictable expression levels in synthetic glycerol medium were required. In the current study, we used transcriptome analysis and a yECitrine-based fluorescence reporter assay to select and characterize useful 25 promoters for driving expression of target genes in S. cerevisiae under the given conditions. The promoters of the genes ALD4 and ADH2 showed 4.2- and 3-fold higher activities compared to the well-known strong TEF1 promoter. Moreover, the collection contains promoters with graded activities in synthetic glycerol medium and different degrees of glucose repression. To demonstrate the general applicability of the promoter collection, we successfully used a subset of the characterized promoters with graded activities in order to optimize growth on glycerol in an engineered derivative of CEN.PK, in which glycerol catabolism exclusively occurs via a non-native DHA pathway.
Project description:Reprogramming a non-methylotrophic industrial host, such as Saccharomyces cerevisiae, to a synthetic methylotroph reprents a huge challenge due to the complex regulation in yeast. Through TMC strategy together with ALE strategy, we completed a strict synthetic methylotrophic yeast that could use methanol as the sole carbon source. However, how cells respond to methanol and remodel cellular metabolic network on methanol were not clear. Therefore, genome-scale transcriptional analysis was performed to unravel the cellular reprograming mechanisms underlying the improved growth phenotype.
Project description:sgRNA whole genome library sequencing in OCI-AML5-Cas9 EKO library cells overexpressing HMGA-YFP or control YFP vectors. The goal of this experiment is to identify synthetic lethal and synthetic rescue sgRNAs with regard to HMGA2 overexpression in AML.