ABSTRACT: Analysis of Caenorhabditis elegans intestinal gene expression and alternative polyadenylation using fluorescence-activated nuclei sorting (FANS) and 3' end deep sequencing (3'end-seq)
Project description:Caenorhabditis elegans is a major eukaryotic experimental system employed to unravel a broad range of cellular and biological processes. Despite the many advantages of C. elegans, biochemical approaches to study tissue-specific gene expression in postembryonic stages are challenging. Here we report a novel experimental approach that enables the efficient determination of tissue-enriched transcriptomes by rapidly releasing nuclei from major tissues of postembryonic animals followed by fluorescence-activated nuclei sorting (FANS). Furthermore, we developed and applied a deep sequencing method, named 3'end-seq, which is designed to examine gene expression and identify 3' ends of transcripts using a small quantity of input RNA. In agreement with intestinal specific gene expression, promoter elements of highly expressed genes are enriched for GATA elements and their functional properties are associated with processes that are characteristic for the intestine. In addition, we systematically mapped pre-mRNA cleavage and polyadenylation sites, or polyA sites, including >3,000 sites that have previously not been identified. The analysis of nuclear mRNA revealed widespread alternative polyA site use in intestinally expressed genes. We describe several novel approaches that will be of significance to the analysis of tissue specific gene expression using small quantity RNA samples from C. elegans and beyond. 3'end-seq of transcriptomes for input and sorted nuclei
Project description:Caenorhabditis elegans is a major eukaryotic experimental system employed to unravel a broad range of cellular and biological processes. Despite the many advantages of C. elegans, biochemical approaches to study tissue-specific gene expression in postembryonic stages are challenging. Here we report a novel experimental approach that enables the efficient determination of tissue-enriched transcriptomes by rapidly releasing nuclei from major tissues of postembryonic animals followed by fluorescence-activated nuclei sorting (FANS). Furthermore, we developed and applied a deep sequencing method, named 3'end-seq, which is designed to examine gene expression and identify 3' ends of transcripts using a small quantity of input RNA. In agreement with intestinal specific gene expression, promoter elements of highly expressed genes are enriched for GATA elements and their functional properties are associated with processes that are characteristic for the intestine. In addition, we systematically mapped pre-mRNA cleavage and polyadenylation sites, or polyA sites, including >3,000 sites that have previously not been identified. The analysis of nuclear mRNA revealed widespread alternative polyA site use in intestinally expressed genes. We describe several novel approaches that will be of significance to the analysis of tissue specific gene expression using small quantity RNA samples from C. elegans and beyond.
Project description:We carried out cell-type specific whole genome bisulfite sequencing from BA46 that underwent fluorescence-activated nuclei sorting (FANS).
Project description:We carried out cell-type specific whole genome bisulfite sequencing from primate brains (orthologous region to human BA46) that underwent fluorescence-activated nuclei sorting (FANS).
Project description:Fluorescence-Activated Nuclei Sorting (FANS)-assisted Assay for Transposase Accessible Chromatin sequencing (ATAC-seq) This work sought to identify endothelial-specific enhancer elements by applying ATAC-Seq to nuclei isolated from Tg(fli1a:egfp) transgenic zebrafish embryos.
Project description:Background: The force generating mechanism of muscle is evolutionarily ancient; the fundamental structural and functional components of the sarcomere are common to motile animals throughout phylogeny. Recent evidence suggests that the transcription factors that regulate muscle development are also conserved. Thus, a comprehensive description of muscle gene expression in a simple model organism should define a basic muscle transcriptome that is also expressed in animals with more complex body plans. To this end, we have applied Micro-Array Profiling of Caenorhabditis elegans Cells (MAPCeL) to muscle cell populations extracted from developing Caenorhabditis elegans embryos. Results: Fluorescence Activated Cell Sorting (FACS) was used to isolate myo-3::GFP-positive muscle cells, and their cultured derivatives, from dissociated early Caenorhabditis elegans embryos. Microarray analysis identified 6,693 expressed genes, 1,305 of which are enriched in the myo-3::GFP positive cell population relative to the average embryonic cell. The muscle-enriched gene set was validated by comparisons to known muscle markers, independently derived expression data, and GFP reporters in transgenic strains. These results confirm the utility of MAPCeL for cell type-specific expression profiling and reveal that 60% of these transcripts have human homologs. Conclusions: This study provides a comprehensive description of gene expression in developing Caenorhabditis elegans embryonic muscle cells. The finding that over half of these muscle-enriched transcripts encode proteins with human homologs suggests that mutant analysis of these genes in Caenorhabditis elegans could reveal evolutionarily conserved models of muscle gene function with ready application to human muscle pathologies. Keywords: embryonic muscle, myo-3::GFP
Project description:To explore the transcriptional heteroeneity of oxytocin neurons, we fluorescence-assisted nuclei sorting (FANS) conditionally tagged nuclei from Oxt-ires-Cre;CAG-Sun1sfGFP mice. All mice were littermates and fed either SC diet or HFHS diet for 4 months. Individual nuclei were sorted into 384w plates and subjected to SMART-seq2.
Project description:Much of posttranscriptional mRNA regulation occurs through cis-acting sequences in mRNA 3´ untranslated regions (UTRs), which interact with specific proteins and ribonucleoprotein complexes that modulate translation, mRNA stability and subcellular localization. Studies in Caenorhabditis elegans have revealed indispensable roles for 3´UTR-mediated gene regulation, yet most C. elegans genes have lacked annotated 3´UTRs. Here we describe a high-throughput method to reliably identify 3´ ends of polyadenylated RNAs. This method, called poly(A)-position profiling by sequencing (3P-Seq), was used to determine the UTRs of C. elegans. Compared to standard methods also recently applied to C. elegans UTRs, 3P-Seq identified 8775 additional UTRs while excluding thousands of shorter UTR isoforms that do not appear to be authentic. Analysis of this expanded and corrected dataset indicated that the high A/U content of C. elegans 3´UTRs facilitated genome compaction, since the elements specifying cleavage and polyadenylation, which are A/U-rich, can more readily emerge in A/U rich regions. Indeed, 30% of the protein-coding genes have mRNAs with alternative, partially overlapping end regions that generate another 10,000 cleavage and polyadenylation sites that had gone largely unnoticed and represent potential evolutionary intermediates of progressive UTR shortening. Moreover, a third of the convergently transcribed genes utilize palindromic arrangements of bidirectional elements to specify UTRs with convergent overlap, which also contributes to genome compaction by eliminating regions between genes. Although nematode 3´UTRs have median length only one-sixth that of mammalian 3´UTRs, they have twice the density of conserved microRNA sites, in part because additional types of seed-complementary sites are preferentially conserved. These findings reveal the influence of cleavage and polyadenylation on the evolution of genome architecture and provide resources for studying posttranscriptional gene regulation. Nine samples (10 sequencing runs) from various mixed and specific stages of wild-type Caenorhabditis elegans and glp-4 mutant adults.
Project description:To characterize the molecular diversity of olfactory bulb projection neurons we used viral targeting and Fluorescence Activated Nuclei Sorting (FANS) to enrich for piriform cortex-projecting or AON-projecting neurons, and bulk RNA deep sequencing (bulk RNA deep seq) to comprehensively characterize their transcriptomes.
Project description:We explored the hypothesis that adipose tissue contains epigenetically distinct subpopulations of adipocytes that are differentially potentiated to record cellular memories of their environment. Adipocytes are large, fragile, and technically difficult to efficiently isolate and fractionate. We developed fluorescence nuclear cytometry (FNC) and fluorescence activated nuclear sorting (FANS) of cellular nuclei from Sus scrofa visceral adipose tissue (SsVAT) using the levels of the pan-adipocyte protein, peroxisome proliferator-activated receptor gamma-2 (PPARg2) to distinguish PPARg2-Positive nuclei from PPARg2-Neg (negative) leukocyte, endothelial, and adipocyte progenitor cell nuclei. PPARg2-Postive VAT nuclei showed 2- to 50-fold higher levels of transcripts encoding most of the chromatin-remodeling factors assayed regulating the methylation of histones and DNA cytosine (e.g., DNMT1, DNMT3A, TET2, TET3, KMT2C, SETDB1, PAXP1, ARID1A, KMT2C, JMJD6, CARM1/PRMT4, PRMT5). PPARg2-Positive nuclei have a large decondensed chromatin structure. TAB-seq demonstrated 5´-hydroxymethylcytosine (5hmC) levels were remarkably dynamic in the gene body of PPARg2-Positive nuclei, dropping 3.8-fold from the highest quintile of expressed genes to the lowest. Sus scrofa VAT (SsVAT) nuclei were isolated from SsVAT. SsVAT nuclei were stained with PPARg2 and sorted with fluorescence activated nuclear sorting (FANS) into PPARg2-High, PPARg2-Med (Medium), PPARg2-Low, and PPARg2-Neg (Negative) four populations.TAB-seq data on 5-hydroxymehtylcytosine (Yu, M. et al. 2012. Cell 149, 1368-1380) was collected from genomic DNA isolated from PPARg2-High, PPARg2-Med+Low (pooled PPARg2-Med and PPARg2-Low), and PPARg2-Neg SsVAT nuclei.