Background: In Saccharomyces cerevisiae genes that are located close to a telomere can become transcriptionally repressed by an epigenetic process known as telomere position effect. There is large variation in the level of the telomere position effect among telomeres, with many native ends exhibiting little repression.
Results: Chromatin analysis, using microccocal nuclease and indirect end labelling, reveals distinct patterns for ends with different silencing states. Differences were observed in the promoter accessibility of a subtelomeric reporter gene and a characteristic array of phased nucleosomes was observed on the centromere proximal side of core X at a repressive end. The silent information regulator proteins 2 - 4, the yKu heterodimer and the subtelomeric core X element are all required for the maintenance of the chromatin structure of repressive ends. However, gene deletions of particular histone modification proteins can eliminate the silencing without the disruption of this chromatin structure.
Conclusion: Our data identifies chromatin features that correlate with the silencing state and indicate that an array of phased nucleosomes is not sufficient for full repression.
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http://dx.doi.org/10.1186/1756-8935-2-18 | DOI Listing |
Appl Microbiol Biotechnol
January 2025
Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.
Lignin, the most abundant renewable source of aromatic compounds on earth, remains underexploited in traditional biorefining. Fraxetin, a naturally occurring flavonoid, has garnered considerable attention in the scientific community due to its diverse and potent biological activities such as antimicrobial, anticancer, antioxidant, anti-inflammatory, and neurological protective actions. To enhance the green and value-added utilization of lignin, Saccharomyces cerevisiae was engineered as a cell factory to transform lignin derivatives to produce fraxetin.
View Article and Find Full Text PDFCurr Protoc
January 2025
Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada.
Competitive fitness is a fundamental concept in evolutionary biology that captures the ability of organisms to survive, reproduce, and compete for resources in their environment. Competitive fitness is typically assessed in the lab by growing two or more competitors together and measuring the frequency of each at multiple time points. Traditional microbial competitive fitness assays are labor intensive and involve plating on solid medium and counting colonies.
View Article and Find Full Text PDFMicrobiol Resour Announc
January 2025
Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA.
Oxford Nanopore Technologies provides multiplexing options for DNA and cDNA sequencing, but not for direct RNA sequencing. Here we describe a duplexing approach and validate it by simultaneously sequencing the rRNA from wild type and knockout that have differential rRNA modifications, successfully demultiplexing the data using bioinformatics approaches.
View Article and Find Full Text PDFPhysiol Plant
January 2025
College of Grassland Science and Technology, Sichuan Agricultural University, Chengdu, China.
The gene GAD1 encodes a glutamate decarboxylase, which is a rate-limiting enzyme for the biosynthesis of endogenous γ-aminobutyrate acid (GABA), but a potential role of GAD1 in regulating cadmium (Cd) tolerance needs to be further elucidated in plants. The objective of this study was to investigate Cd tolerance of creeping bentgrass (Agrostis stolonifera) and transgenic yeast (Saccharomyces cerevisiae) or Arabidopsis thaliana overexpressing AsGAD1. The Cd-tolerant creeping bentgrass cultivar LOFTSL-93 accumulated more endogenous GABA in relation to a significant upregulation of AsGAD1 in leaf and root than the Cd-sensitive W66569 in response to Cd stress.
View Article and Find Full Text PDFJ Food Sci Technol
February 2025
Program of Medical Technology, Faculty of Allied Health Sciences, Chonburi, 20130 Thailand.
Unlabelled: The aim of this study was to utilize four rice pasta by-products (RPB), including white rice pasta, black jasmine rice pasta, red jasmine rice pasta and brown rice pasta, to ferment into four vinegars. The dynamic variations during fermentation and their quality were evaluated. During alcoholic fermentation, the saccharified substrates were fermented with for 12 days, resulting in an alcohol yield of approximately 10% (v/v) after 4 days of fermentation.
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