High-Throughput Transcriptome Profiling of Single Nuclei and Single Synapses Using Single-Cell Total-RNA-Seq [Mm]
Ontology highlight
ABSTRACT: We developed the first droplet-based single-cell total-RNA-seq method. We refer to this platform as Multiple Annealing and Tailing-based Quantitative scRNA-seq in Droplet (MATQ-Drop). With the detection of nascent RNA species, we showed that the cell atlas of human brain samples could be effectively constructed based on nascent RNA species. Furthermore, we observed that only lncRNA species are sufficient to construct the cell atlas, suggesting that MATQ-Drop allows a large-scale identification of the cell-type-specific lncRNA species. Beyond total-RNA profiling for single nuclei, we also showed that MATQ-Drop could be used to profile the transcripts in different neuronal sub-compartments. Based on transcriptome profiling, we were able to determine different types of sub-compartments—in particular, synapses. Here we have referred to the transcriptome of individual synapses as the synaptome, and we identified different subtypes of pre-synapses and post-synapses. Furthermore, between pre-synapses and post-synapses, as well as between pre-synapses and the nuclei, we were able to identify different functional enrichments. Our result unveils unprecedented new insights about gene expression in individual synapses. It also demonstrates the feasibility of using MATQ-drop to profile the transcriptome of sub-cellular compartments.
Project description:We developed the first droplet-based single-cell total-RNA-seq method. We refer to this platform as Multiple Annealing and Tailing-based Quantitative scRNA-seq in Droplet (MATQ-Drop). With the detection of nascent RNA species, we showed that the cell atlas of human brain samples could be effectively constructed based on nascent RNA species. Furthermore, we observed that only lncRNA species are sufficient to construct the cell atlas, suggesting that MATQ-Drop allows a large-scale identification of the cell-type-specific lncRNA species. Beyond total-RNA profiling for single nuclei, we also showed that MATQ-Drop could be used to profile the transcripts in different neuronal sub-compartments. Based on transcriptome profiling, we were able to determine different types of sub-compartments—in particular, synapses. Here we have referred to the transcriptome of individual synapses as the synaptome, and we identified different subtypes of pre-synapses and post-synapses. Furthermore, between pre-synapses and post-synapses, as well as between pre-synapses and the nuclei, we were able to identify different functional enrichments. Our result unveils unprecedented new insights about gene expression in individual synapses. It also demonstrates the feasibility of using MATQ-drop to profile the transcriptome of sub-cellular compartments.
Project description:In this work, we have improved our previously published bacterial single-cell RNA-sequencing protocol (MATQ-seq), providing enhancements that achieve a higher cell throughput while also including integration of automation. We selected a more efficient reverse transcriptase which led to a lower drop-out rate and higher workflow robustness, and we also successfully implemented a Cas9-based ribosomal RNA depletion protocol into the MATQ-seq workflow. Applying this improved protocol on a large set of single Salmonella cells sampled over growth revealed improved gene coverage and a higher gene detection limit, allowing us to reveal the expression of small regulatory RNAs such as GcvB or CsrB at a single-cell level. In addition, we were able to confirm previously described phenotypic heterogeneity in Salmonella in regards to expression of pathogenicity-associated genes.
Project description:In this work, we have improved our previously published bacterial single-cell RNA-sequencing protocol (MATQ-seq), providing enhancements that achieve a higher cell throughput while also including integration of automation. We selected a more efficient reverse transcriptase which led to a lower drop-out rate and higher workflow robustness, and we also successfully implemented a Cas9-based ribosomal RNA depletion protocol into the MATQ-seq workflow. Applying this improved protocol on a large set of single Salmonella cells sampled over growth revealed improved gene coverage and a higher gene detection limit, allowing us to reveal the expression of small regulatory RNAs such as GcvB or CsrB at a single-cell level. In addition, we were able to confirm previously described phenotypic heterogeneity in Salmonella in regards to expression of pathogenicity-associated genes.
Project description:The ability to measure the number of gene-specific mRNA molecules in individual mammalian cells has transformed the transcriptomics field. Among the key technologies enabling single-cell mRNA sequencing has been Droplet Sequencing (Drop-Seq). While this method works efficiently for mammalian cells, its direct application to yeast cells has been problematic due to cell-type specific differences such as size, doublet formation rate, and cell wall. Here we introduce YeastDropSeq, a single-cell RNA sequencing method for the study of transcriptomics in yeast. We modified and optimized the original Drop-Seq method to address the issues that emerged from smaller cell sizes and the presence of a cell wall in yeast. We also quantified the rate of doublet formation through a species-mixing experiment. As proof-of-principle application of the YeastDropSeq, we investigated the transcriptomic effects of mycophenolic acid (MPA), a lifespan-extending compound that decreases de novo GMP synthesis. We compared transcript levels between cells treated with MPA and cells treated with DMSO and/or guanine, MPA’s epistatic agent. We discovered that isogenic populations of yeast cells contain transcriptionally distinct subpopulations and that the subpopulation structures were maintained despite the different treatment conditions. We found that cells treated with MPA experience an upregulation of genes coding for proteins involved in DNA replication stress-response, antioxidation, pre-RNA processing, and translation initiation. Conversely, a downregulation of mRNA expression was observed for genes encoding translation initiation and elongation factors, the 40S and 60S ribosomal subunits, and for genes involved in metal transport and mitochondrial function. Additionally, we elucidated that expression levels of several genes of unknown function were affected by the MPA treatment. YeastDropSeq will accelerate biological discovery by facilitating droplet-based transcriptomics of yeast cells.
Project description:Motivation: Computational inference of genome organization based on Hi-C sequencing has greatly aided the understanding of chromatin and nuclear organization in three dimensions (3D). However, existing computational methods fail to address the cell population heterogeneity. Here we describe a probabilistic modeling-based method called CscoreTool-M that infers multiple 3D genome sub-compartments from Hi-C data. Results: The compartment scores inferred using CscoreTool-M represents the probability of a genomic region locating in a specific sub-compartment. Compared to published methods, CscoreTool-M is more accurate in inferring sub-compartments corresponding to both active and repressed chromatin. The compartment scores calculated by CscoreTool-M also help to quantify the levels of heterogeneity in sub-compartment localization within cell populations. By comparing proliferating cells and terminally differentiated non-proliferating cells, we show that the proliferating cells have higher genome organization heterogeneity, which is likely caused by cells at different cell-cycle stages. By analyzing 10 sub-compartments, we found a sub-compartment containing chromatin potentially related to the early-G1 chromatin regions proximal to the nuclear lamina in HCT116 cells, suggesting the method can deconvolve cell cycle stage-specific genome organization among asynchronously dividing cells. Finally, we show that CscoreTool-M can identify sub-compartments that contain genes enriched in housekeeping or cell-type-specific functions. Availability: https://github.com/scoutzxb/CscoreTool-M
Project description:A bead supsension and a solution of ERCC spike-ins at a concentration of ~100,000 molecules per droplet was used in Drop-Seq, a novel technology for high-throughput single cell mRNAseq An estimated 84 beads were selected for amplification.
Project description:Here we aim to decipher the actions of Irx5 in the regulation of obesity and metabolic abnormalities. We employed a mouse model homozygous for an Irx5-knockout (Irx5KO) allele and conducted droplet based single-cell RNA sequencing (Drop-seq) in the hypothalamic arcuate-median eminence (ARC-ME), which is the main control center for sensing and integrating feeding regulatory signals.
Project description:The ability to measure the number of gene-specific mRNA molecules in individual mammalian cells has transformed the transcriptomics field. Among the key technologies enabling single-cell mRNA sequencing has been Droplet Sequencing (Drop-Seq). While this method works efficiently for mammalian cells, its direct application to yeast cells has been problematic due to cell-type specific differences such as size, doublet formation rate, and cell wall. Here we introduce YeastDropSeq, a single-cell RNA sequencing method for the study of transcriptomics in yeast. We modified and optimized the original Drop-Seq method to address the issues that emerged from smaller cell sizes and the presence of a cell wall in yeast. As proof-of-principle application of the YeastDropSeq, we investigated the transcriptomic effects of mycophenolic acid (MPA), a lifespan-extending compound that decreases de novo GMP synthesis. We compared transcript levels between cells treated with MPA and cells treated with DMSO and/or guanine, MPA’s epistatic agent. We discovered that isogenic populations of yeast cells contain transcriptionally distinct subpopulations and that the subpopulation structures were maintained despite the different treatment conditions. We found that cells treated with MPA experience an upregulation of genes coding for proteins involved in DNA replication stress-response, antioxidation, pre-RNA processing, and translation initiation. Conversely, a downregulation of mRNA expression was observed for genes encoding translation initiation and elongation factors, the 40S and 60S ribosomal subunits, and for genes involved in metal transport and mitochondrial function. YeastDropSeq will accelerate biological discovery by facilitating droplet-based transcriptomics of yeast cells.
Project description:Emerging 3D genome mapping efforts suggest complex chromosomal folding structures. However, the true multiplex nature of chromatin interactions has yet to be fully explored. Here, we describe a chromatin interaction analysis by droplet-based sequencing (ChIA-Drop). In ChIA-Drop, individual chromatin complexes are partitioned into droplets that contain a gel bead of DNA-barcoded primers, such that tethered chromatin DNA fragments are uniquely indexed and amplified for sequencing and mapping to demarcate multiplex chromatin contacts. Thus, ChIA-Drop can identify complex chromatin interactions with unprecedented single-molecule precision, which is not possible using methods that analyze pairwise contacts via proximity ligation. We demonstrate that multiplex chromatin interactions predominantly contribute to topologically associated domains with high heterogeneity, and that multivalent promoter-centered interactions provide a topological model for gene transcription.
Project description:A bead supsension and a solution of ERCC spike-ins at a concentration of ~100,000 molecules per droplet was used in Drop-Seq, a novel technology for high-throughput single cell mRNAseq