Project description:Low-pass sequencing (sequencing a genome to an average depth less than 1× coverage) combined with genotype imputation has been proposed as an alternative to genotyping arrays for trait mapping and calculation of polygenic scores. To empirically assess the relative performance of these technologies for different applications, we performed low-pass sequencing (targeting coverage levels of 0.5× and 1×) and array genotyping (using the Illumina Global Screening Array (GSA)) on 120 DNA samples derived from African and European-ancestry individuals that are part of the 1000 Genomes Project. We then imputed both the sequencing data and the genotyping array data to the 1000 Genomes Phase 3 haplotype reference panel using a leave- one-out design. We evaluated overall imputation accuracy from these different assays as well as overall power for GWAS from imputed data, and computed polygenic risk scores for coronary artery disease and breast cancer using previously derived weights. We conclude that low-pass sequencing plus imputation, in addition to providing a substantial increase in statistical power for genome wide association studies, provides increased accuracy for polygenic risk prediction at effective coverages of ∼ 0.5× and higher compared to the Illumina GSA.
2021-01-31 | GSE165845 | GEO
Project description:Genotype imputation from low-coverage whole-genome sequencing data of rainbow trout
Project description:Low coverage whole-genome sequencing have been performed on uterine leiomyosarcoma to uncovered novel potential driver genes and recurrently affected pathways.
Project description:In order to validate of CNV detection from low-coverage whole-genome sequencing in the blood samples from recurrent miscarriage couples, we employed a customized array Comparative Genomics Hybridization (aCGH, Agilent) approach as chromosomal microarray analysis (CMA) in present study for a cohort of 78 DNA samples from blood. CMA results were compared with low-coverage whole-genome sequencing detection results. 100% consistency was obtained in pathogenic or likely pathogenic CNVs detection.
Project description:Mouse embryonic stem cells (i.e., mESCs; line ESC 129-B13) were genetically modified using CRISPR-Cas9 to mutate the H3f3b locus, in order to carry homozygous lysine-to-alanine substitution of residues K9, K27 or K79. Two control mESC lines carrying knock-out of the H3f3a gene were used as background for the editing. Low-coverage whole-genome sequencing (~0.8/0.9X) was performed to assess the chromosomal integrity of the edited lines. Genomic DNA was extracted from each mutant and control mESC line and sonicated to obtain fragments of ~150-200bp on average. Fragmented DNA (~0.5-1 ug) was used for library preparation using the NEBNext Ultra II DNA library preparation kit (New England Biolabs). Sequencing was performed on a NextSeq500 platform in single-end mode (75bp reads).
Project description:To address how genetic variation alters gene expression in complex cell mixtures, we developed Direct Nuclear Tagmentation and RNA-sequencing (DNTR-seq), which enables whole genome and mRNA sequencing jointly in single cells. DNTR-seq readily identified minor subclones within leukemia patients. In a large-scale DNA damage screen, DNTR-seq was used to detect regions under purifying selection, and identified genes where mRNA abundance was resistant to copy number alteration, suggesting strong genetic compensation. mRNA-seq quality equals RNA-only methods, and the low positional bias of genomic libraries allowed detection of sub-megabase aberrations at ultra-low coverage. Each cell library is individually addressable and can be re-sequenced at increased depth, allowing multi-tiered study designs. Additionally, the direct tagmentation protocol enables coverage-independent estimation of ploidy, which can be used to identify cell singlets. Thus, DNTR-seq directly links each cell?s state to its corresponding genome at scale, enabling routine analysis of heterogeneous tumors and other complex tissues.
Project description:Low coverage whole genome sequencing (lc-WGS) from inducible Tet TKO (Tet iTKO) and control (Ctrl) mouse ESCs (mESC), as well as for germline Dnmt TKO mESCs. mESCs were sorted to isolate the Live/Dead dye and Thy1.2 negative CD326+GFP+ population representing the mESCs populations responsive to the tamoxifen treatment. The cells were resuspended in FACS buffer and filtered with a 70 µM filter before sorting. These bulk-population samples were analyzed by using low coverage Whole Genome Sequencing (lc-WGS).
Project description:Whole genome UV footprinting in yeast using deamination sequencing (Deam-seq), wherein photoproducts induced by high-dose UVB irradiation are revealed as mutations. In Deam-seq, cytosines within cyclobutane pyrimidine dimers (CPDs) are converted to uracil by rapid deamination at elevated temperature. Following CPD repair by photolyase, samples were sequenced at ultra-deep (>7,000×) coverage, enabling calculation of per-base damage fractions (mutant allele frequencies). By comparing cellular and naked DNA, this approach can pinpoint genomic sites bound by proteins that modulate UV damage.
Project description:Whole-genome DNA libraries were prepared from a population of just under 100 Col/Ler F1 backcrossed to Col. Low-coverage whole-genome sequencing was used to map meiotic crossovers in this population following the protocol described in Rowan et al., 2015, doi: 10.1534/g3.114.016501.