Project description:In order to address the replication timing of the centromeres in yeast Candida albicans, we have determined at high temporal and spatial resolution its genome-wide DNA replication timing profile. This was done by sorting S- and G1-phase cells by FACS and hybridizing DNA from both fractions onto genomic tiling arrays. Data was normalized, organized by chromosomal positition, and smoothed. Replication timing is inferred from the DNA copy number along the chromosome with data peaks corresponding to predicted origins of DNA replication. We observe that the centromeric loci coincide with replication origins that are the first to replicate on each chromosome. We further analyzed replication timing in strain 9929s, in which the centromere of chromosome 5 was deleted and a neocentromere has formed at a distant location. A replication origin, again the first to replicate, appeared at the site of neocentromere formation. We conclude that centromeres cause their own early and distinct DNA replication timing.
Project description:Enzymatic methylation of cytosine to 5-methylcytosine in DNA is a fundamental epigenetic mechanism involved in mammalian development and disease. DNA methylation is brought about by collective action of three AdoMet-dependent DNA methyltransferases (DNMTs), whose catalytic interactions and temporal interplay are poorly understood. We used structure-guided engineering of the Dnmt1 methyltransferase to enable catalytic transfer of azide tags onto DNA from a synthetic cofactor analog, Ado-6-azide, in vitro . We then CRISPR-edited the Dnmt1 locus in mouse embryonic stem cells to install the engineered codon, which, following pulse- internalization of the Ado-6-azide cofactor by electroporation, permitted selective azide-tagging of Dnmt1-specific genomic targets in cellula . The deposited covalent tags were exploited as ‘click’ handles for reading adjoining sequences and precise genomic mapping of the methylation sites. The proposed approach, Dnmt-TOP-seq, enables high-resolution temporal tracking of the Dnmt1 catalysis in mammalian cells paving the way to selective studies of other methylation pathways in eukaryotic systems.
Project description:This SuperSeries is composed of the following subset Series: GSE29642: Arabidopsis defense against Botrytis cinerea: chronology and regulation deciphered by high-resolution temporal transcriptomic analysis (time series) GSE39597: Arabidopsis defense against Botrytis cinerea: chronology and regulation deciphered by high-resolution temporal transcriptomic analysis (tga3-2 knockout data) Refer to individual Series
Project description:We report a method for precisely stenciling the structure of individual chromatin fibers onto their composite DNA templates using non-specific DNA N6-adenine methyltransferases. Single-molecule long-read sequencing using PacBio of these chromatin stencils enables nucleotide-resolution readout of the primary architecture of multi-kilobase chromatin fibers (Fiber-seq).
Project description:We report a method for precisely stenciling the structure of individual chromatin fibers onto their composite DNA templates using non-specific DNA N6-adenine methyltransferases. Single-molecule long-read sequencing using PacBio of these chromatin stencils enables nucleotide-resolution readout of the primary architecture of multi-kilobase chromatin fibers (Fiber-seq).
Project description:We report a method for precisely stenciling the structure of individual chromatin fibers onto their composite DNA templates using non-specific DNA N6-adenine methyltransferases. Single-molecule long-read sequencing using PacBio of these chromatin stencils enables nucleotide-resolution readout of the primary architecture of multi-kilobase chromatin fibers (Fiber-seq).
Project description:We report a method for precisely stenciling the structure of individual chromatin fibers onto their composite DNA templates using non-specific DNA N6-adenine methyltransferases. Single-molecule long-read sequencing using PacBio of these chromatin stencils enables nucleotide-resolution readout of the primary architecture of multi-kilobase chromatin fibers (Fiber-seq).
Project description:We report a method for precisely stenciling the structure of individual chromatin fibers onto their composite DNA templates using non-specific DNA N6-adenine methyltransferases. Single-molecule long-read sequencing using PacBio of these chromatin stencils enables nucleotide-resolution readout of the primary architecture of multi-kilobase chromatin fibers (Fiber-seq).
Project description:Dynamic proteins and multi-protein complexes govern most biological processes. Cross-linking/mass spectrometry (CLMS) is increasingly successful in providing residue-resolution data on static proteinaceous structures. In order to investigate the technical feasibility of recording dynamic processes using isotope-labelling for quantitation, we generated a model dataset by cross-linking human serum albumin (HSA) with the readily available cross-linker BS3-d0/d4 in different heavy/light ratios.
