DIRECT: Digital Microfluidics for Isolation-Free Shared Library Construction of Single-Cell DNA Methylome and Transcriptome
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ABSTRACT: Integrated single-cell transcriptome and DNA methylome profiling has provided insight into the complex regulatory networks of cells. Existing methods are based on picking a single-cell and performing library construction in a tube, which is costly and cumbersome. Here, we propose DIRECT, a digital microfluidics-based method for simultaneous analysis of the methylome and transcriptome in a single library construction. The accuracy of DIRECT is demonstrated in comparison with bulk and single-omics data, and the high CpG site coverage of DIRECT allows for precise analysis of copy number variation information, enabling expansion of single cell analysis from two- to three-omics. By applying DIRECT to monitor the dynamics of mouse embryonic stem cell differentiation, the relationship between DNA methylation and changes in gene expression during differentiation was revealed. DIRECT enables accurate, robust, and reproducible single-cell DNA methylation and gene expression co-analysis at a lower cost and with greater efficiency, broadening the application scenarios of single-cell multi-omics analysis and revealing a more comprehensive and fine-grained map of cellular regulatory landscapes.
Project description:Ribosome profiling has emerged as a powerful tool for genome-wide measurements of translation, but library construction requires multiple ligation steps and remains cumbersome relative to more conventional deep sequencing experiments. We report a new approach to ribosome profiling that does not require ligation. Library construction for ligation-free ribosome profiling can be completed in one day with as little as 1 ng of purified RNA footprints. We used ligation-free ribosome profiling to identify new patterns of cell type-specific translation in the brain and tested its ability to identify translational targets of mTOR signaling in the brain.
Project description:Single-cell DNA methylation sequencing is a powerful method for elucidating important physiological and pathological processes, identifying cell subpopulations, and constructing epigenetic regulatory networks. Existing methylome analyses typically require substantial starting materials, complex operations, and high cost and are susceptible to contamination. These problems have impeded the development of single-cell methylome technology for rare cell profiling. In this work, we report Digital Microfluidics-based single-cell Reduced Representation Bisulfite Sequencing (Digital-scRRBS), the first microfluidics-based single-cell methylome library construction platform, which is an automatic, efficient, reproducible, and reagent-economy approach to dissect the single-cell methylome. Taking advantage of our uniquely designed digital microfluidic chip, we realized efficient single-cell isolation in less than 15 seconds. Furthermore, with the advantages of a confined environment, superhydrophobic surface, and nano-scale reaction volume of our digital microfluidic chip, more amplifiable DNA is retained for library construction compared to other approaches. We have successfully constructed single-cell methylation sequencing libraries with a unique genome mapping rate of up to 53.6%, covering up to 2.26 million CpG sites. The application of Digital-scRRBS allows us to discriminate cell identity and dynamically monitor DNA methylation levels during drug administration. Digital-scRRBS provides the technology for widespread application of single-cell methylation methods as a versatile tool for epigenetic analysis in rare cells and highly heterogeneous populations.
Project description:Single cell genome, DNA methylome, and transcriptome sequencing has been achieved separately. However, to analyze the regulation of RNA expression by genetic and epigenetic factors within an individual cell, it is necessary to analyze these omics simultaneously from the same single cell. Here we developed a single cell triple omics sequencing technique- scTrio-seq, to analyze the genome, DNA methylome, and transcriptome concurrently of a mammalian cell. 6 single human HepG2 cell line cells were sequenced using the newly developed scTrio-seq, other 2 HepG2 cells were sequenced using scRNA-seq and other 2 HepG2 cells were sequenced using scRRBS as technique control. 6 single mouse embryonic stem cells (mESCs) were sequenced using the newly developted scTrio-seq. Meanwhile, two scRNA-seq and two scRRBS were also completed using two mESCs separately. 26 single cells from hepatocellular carcinoma were sequenced using scTrio-seq to analyze the regulation relations between three omics of cancer cells.
Project description:We improved the tagmentation-based whole genome bisulfite sequencing technology, enabling stable library construction with complexity from minimally 0.5ng of initial genomic DNA, which equals less than 100 cells. This new approach is highly attractive for the complete methylome analysis of very limited cell numbers, e.g., pre-implantation embryos, or tiny biopsy specimens.
Project description:Single cell genome, DNA methylome, and transcriptome sequencing has been achieved separately. However, to analyze the regulation of RNA expression by genetic and epigenetic factors within an individual cell, it is necessary to analyze these omics simultaneously from the same single cell. Here we developed a single cell triple omics sequencing technique- scTrio-seq, to analyze the genome, DNA methylome, and transcriptome concurrently of a mammalian cell.
Project description:We improved the tagmentation-based whole genome bisulfite sequencing technology, enabling stable library construction with complexity from minimally 0.5ng of initial genomic DNA, which equals less than 100 cells. This new approach is highly attractive for the complete methylome analysis of very limited cell numbers, e.g., pre-implantation embryos, or tiny biopsy specimens. Applying this newly modified T-WGBS, we sequenced the methylome of a rice strain using libraries constructed from 10 ng, 1 ng and 0.5 ng of input genomic DNA. Two libraries were independently constructed and sequenced for each aliquot of input genomic DNA
Project description:Primordial germ cell mRNA profiles from cells microdissected from e6.5, e7.5 and e8.5 embryos, e7.5 somatic neighbours and Blimp1-KO mice were generated by single cell library construction and sequencing in duplicate using Applied Biosystems SOLiD sequencer. Single cell library construction is described in: Tang f. et. al, Nature Protocols (2010), Vol. 5, p.516.
Project description:Using a custom primer set for cDNA library construction we performed single cell RNA sequencing on FACs sorted tdTomato positive cells from single cell suspensions prepared from the hypothalamus of mice expressing cre-recombinase under the endogenus KLB promoter that were crossed with tdTomato reporter mice (Ai14). We then performed unbiased clustering analysis on 1,904 cells using the single cell transcriptomes to identify 12 different cell types which express KLB in the hypothalamus including neuronal and non-neuronal cell types. This information was then used to delete KLB in specific cell populations to determine the direct target of FGF21 in the brain responsible for suppression of sucrose preference.
Project description:Developing a single-cell multi-omics technology with mtDNA mutation profiling at its core will enable precise determination of the relationship between mtDNA mutations and cellular phenotypes. To date, the development of permeability-engineered compartmentalization for the isolation and single-cell library preparation of individual cells, which includes Tn5 tagmentation and single-cell barcoding operations in the permeabilized microcapsule format, remains a formidable challenge. Herein, we present a approach for single-cell mitochondrial analysis, harnessing microfluidics to generate heterogeneous hydrogels as artificial membranes. These hydrogels serve to regulate the passage of mitochondrial DNA and nuclear genomes subsequent to the cell lysis step. This approach enables high-throughput mitochondrial DNA genotyping and accessible chromatin profiling at the single-cell level, significantly enhancing the capabilities of permeability-engineered compartmentalization.We conducted a comprehensive evaluation of cell retention and the selective permeability of the capsule reaction system, optimizing conditions for cell lysis, Tn5 tagmentation, and barcode labeling. Validation experiments were performed using Human 293T and Mouse 3T3 cells to assess identification and quantification performance. Our method offers a new strategy for the study of the functions of various mtDNA mutations in biological processes, while also offering a new system for the construction of single-cell multi-omics libraries.