Project description:<p>Recently developed methods that utilize partitioning of long genomic DNA fragments, and barcoding of shorter fragments derived from them, have succeeded in retaining long-range information in short sequencing reads. These so-called read cloud approaches represent a powerful, accurate, and cost-effective alternative to single-molecule long-read sequencing. We developed software, GROC-SVs, that takes advantage of read clouds for structural variant detection and assembly. We apply the method to two 10x Genomics data sets, one chromothriptic sarcoma with several spatially separated samples, and one breast cancer cell line, all Illumina-sequenced to high coverage. Comparison to short-fragment data from the same samples, and validation by mate-pair data from a subset of the sarcoma samples, demonstrate substantial improvement in specificity of breakpoint detection compared to short-fragment sequencing, at comparable sensitivity, and vice versa. The embedded long-range information also facilitates sequence assembly of a large fraction of the breakpoints; importantly, consecutive breakpoints that are closer than the average length of the input DNA molecules can be assembled together and their order and arrangement reconstructed, with some events exhibiting remarkable complexity. These features facilitated an analysis of the structural evolution of the sarcoma. In the chromothripsis, rearrangements occurred before copy number amplifications, and using the phylogenetic tree built from point mutation data, we show that single nucleotide variants and structural variants are not correlated. We predict significant future advances in structural variant science using 10x data analyzed with GROC-SVs and other read cloud-specific methods.</p>
Project description:Active regulatory elements in eukaryotes are typically characterized by an open, nucleosome-depleted chromatin structure; mapping areas of open chromatin has accordingly emerged as a widely used tool in the arsenal of modern functional genomics. However, existing approaches for profiling chromatin accessibility are limited by their reliance on DNA fragmentation and short read sequencing, which leaves them unable to provide information about the state of chromatin on larger scales or reveal coordination between the chromatin state of individual distal regulatory elements. To address these limitations, we have developed a method for profiling accessibility of individual chromatin fibers at multi-kilobase length scale (SMAC-seq, or Single-Molecule long-read Acessible Chromatin mapping sequencing assay), enabling the simultaneous, high-resolution, single-molecule assessment of the chromatin state of distal genomic elements. Our strategy is based on combining the preferential methylation of open chromatin regions by DNA methyltransferases (CpG and GpC 5-methylcytosine (5mC) and N6-methyladenosine (m6A) enzymes) and the ability of long-read single-molecule nanopore sequencing to directly read out the methylation state of individual DNA bases. Applying SMAC-seq to the budding yeast Saccharomyces cerevisiae, we demonstrate that aggregate SMAC-seq signals match bulk-level accessibility measurements, observe single-molecule protection footprints of nucleosomes and transcription factors, and quantify the correlation between the chromatin states of distal genomic elements
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).
2020-06-25 | GSE146941 | GEO
Project description:Rapid detection of myeloid neoplasm fusions using single-molecule long-read sequencing