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Xie Z, Chai Y, Zhu Z, Shen Z, Guo Z, Zhao Z, Xiao L, Du Z, Ou G, Li W. Vacuolar H +-ATPase determines daughter cell fates through asymmetric segregation of the nucleosome remodeling and deacetylase complex. eLife 2024; 12:RP89032. [PMID: 38994733 PMCID: PMC11245309 DOI: 10.7554/elife.89032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/13/2024] Open
Abstract
Asymmetric cell divisions (ACDs) generate two daughter cells with identical genetic information but distinct cell fates through epigenetic mechanisms. However, the process of partitioning different epigenetic information into daughter cells remains unclear. Here, we demonstrate that the nucleosome remodeling and deacetylase (NuRD) complex is asymmetrically segregated into the surviving daughter cell rather than the apoptotic one during ACDs in Caenorhabditis elegans. The absence of NuRD triggers apoptosis via the EGL-1-CED-9-CED-4-CED-3 pathway, while an ectopic gain of NuRD enables apoptotic daughter cells to survive. We identify the vacuolar H+-adenosine triphosphatase (V-ATPase) complex as a crucial regulator of NuRD's asymmetric segregation. V-ATPase interacts with NuRD and is asymmetrically segregated into the surviving daughter cell. Inhibition of V-ATPase disrupts cytosolic pH asymmetry and NuRD asymmetry. We suggest that asymmetric segregation of V-ATPase may cause distinct acidification levels in the two daughter cells, enabling asymmetric epigenetic inheritance that specifies their respective life-versus-death fates.
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Affiliation(s)
- Zhongyun Xie
- Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, McGovern Institute for Brain Research, State Key Laboratory of Membrane Biology, School of Life Sciences and MOE Key Laboratory for Protein Science, Tsinghua UniversityBeijingChina
| | - Yongping Chai
- Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, McGovern Institute for Brain Research, State Key Laboratory of Membrane Biology, School of Life Sciences and MOE Key Laboratory for Protein Science, Tsinghua UniversityBeijingChina
| | - Zhiwen Zhu
- Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, McGovern Institute for Brain Research, State Key Laboratory of Membrane Biology, School of Life Sciences and MOE Key Laboratory for Protein Science, Tsinghua UniversityBeijingChina
| | - Zijie Shen
- Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, McGovern Institute for Brain Research, State Key Laboratory of Membrane Biology, School of Life Sciences and MOE Key Laboratory for Protein Science, Tsinghua UniversityBeijingChina
| | - Zhengyang Guo
- Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, McGovern Institute for Brain Research, State Key Laboratory of Membrane Biology, School of Life Sciences and MOE Key Laboratory for Protein Science, Tsinghua UniversityBeijingChina
| | - Zhiguang Zhao
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, University of Chinese Academy of SciencesBeijingChina
| | - Long Xiao
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, University of Chinese Academy of SciencesBeijingChina
| | - Zhuo Du
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, University of Chinese Academy of SciencesBeijingChina
| | - Guangshuo Ou
- Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, McGovern Institute for Brain Research, State Key Laboratory of Membrane Biology, School of Life Sciences and MOE Key Laboratory for Protein Science, Tsinghua UniversityBeijingChina
| | - Wei Li
- School of Medicine, Tsinghua UniversityBeijingChina
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2
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Paolillo VK, Ochs ME, Lundquist EA. MAB-5/Hox regulates the Q neuroblast transcriptome, including cwn-1/Wnt, to mediate posterior migration in Caenorhabditis elegans. Genetics 2024; 227:iyae045. [PMID: 38652773 PMCID: PMC11151924 DOI: 10.1093/genetics/iyae045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 03/14/2024] [Indexed: 04/25/2024] Open
Abstract
Neurogenesis involves the precisely coordinated action of genetic programs controlling large-scale neuronal fate specification down to terminal events of neuronal differentiation. The Q neuroblasts in Caenorhabditis elegans, QL on the left and QR on the right, divide, differentiate, and migrate in a similar pattern to produce three neurons each. However, QL on the left migrates posteriorly, and QR on the right migrates anteriorly. The MAB-5/Hox transcription factor is necessary and sufficient for posterior Q lineage migration and is normally expressed only in the QL lineage. To define genes controlled by MAB-5 in the Q cells, fluorescence-activated cell sorting was utilized to isolate populations of Q cells at a time in early L1 larvae when MAB-5 first becomes active. Sorted Q cells from wild-type, mab-5 loss-of-function (lof), and mab-5 gain-of-function (gof) mutants were subject to RNA-seq and differential expression analysis. Genes enriched in Q cells included those involved in cell division, DNA replication, and DNA repair, consist with the neuroblast stem cell identity of the Q cells at this stage. Genes affected by mab-5 included those involved in neurogenesis, neural development, and interaction with the extracellular matrix. cwn-1, which encodes a Wnt signaling molecule, showed a paired response to mab-5 in the Q cells: cwn-1 expression was reduced in mab-5(lof) and increased in mab-5(gof), suggesting that MAB-5 is required for cwn-1 expression in Q cells. MAB-5 is required to prevent anterior migration of the Q lineage while it transcriptionally reprograms the Q lineage for posterior migration. Functional genetic analysis revealed that CWN-1 is required downstream of MAB-5 to inhibit anterior migration of the QL lineage, likely in parallel to EGL-20/Wnt in a noncanonical Wnt pathway. In sum, work here describes a Q cell transcriptome, and a set of genes regulated by MAB-5 in the QL lineage. One of these genes, cwn-1, acts downstream of mab-5 in QL migration, indicating that this gene set includes other genes utilized by MAB-5 to facilitate posterior neuroblast migration.
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Affiliation(s)
- Vitoria K Paolillo
- Department of Molecular Biosciences, KU Center for Genomics, University of Kansas, 1200 Sunnyside Avenue, Lawrence, KS 66045, USA
| | - Matthew E Ochs
- Department of Molecular Biosciences, KU Center for Genomics, University of Kansas, 1200 Sunnyside Avenue, Lawrence, KS 66045, USA
| | - Erik A Lundquist
- Department of Molecular Biosciences, KU Center for Genomics, University of Kansas, 1200 Sunnyside Avenue, Lawrence, KS 66045, USA
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3
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Hameed R, Naseer A, Saxena A, Akbar M, Toppo P, Sarkar A, Shukla SK, Nazir A. Functional implications of NHR-210 enrichment in C. elegans cephalic sheath glia: insights into metabolic and mitochondrial disruptions in Parkinson's disease models. Cell Mol Life Sci 2024; 81:202. [PMID: 38691171 PMCID: PMC11063106 DOI: 10.1007/s00018-024-05179-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 02/08/2024] [Accepted: 02/18/2024] [Indexed: 05/03/2024]
Abstract
Glial cells constitute nearly half of the mammalian nervous system's cellular composition. The glia in C. elegans perform majority of tasks comparable to those conducted by their mammalian equivalents. The cephalic sheath (CEPsh) glia, which are known to be the counterparts of mammalian astrocytes, are enriched with two nuclear hormone receptors (NHRs)-NHR-210 and NHR-231. This unique enrichment makes the CEPsh glia and these NHRs intriguing subjects of study concerning neuronal health. We endeavored to assess the role of these NHRs in neurodegenerative diseases and related functional processes, using transgenic C. elegans expressing human alpha-synuclein. We employed RNAi-mediated silencing, followed by behavioural, functional, and metabolic profiling in relation to suppression of NHR-210 and 231. Our findings revealed that depleting nhr-210 changes dopamine-associated behaviour and mitochondrial function in human alpha synuclein-expressing strains NL5901 and UA44, through a putative target, pgp-9, a transmembrane transporter. Considering the alteration in mitochondrial function and the involvement of a transmembrane transporter, we performed metabolomics study via HR-MAS NMR spectroscopy. Remarkably, substantial modifications in ATP, betaine, lactate, and glycine levels were seen upon the absence of nhr-210. We also detected considerable changes in metabolic pathways such as phenylalanine, tyrosine, and tryptophan biosynthesis metabolism; glycine, serine, and threonine metabolism; as well as glyoxalate and dicarboxylate metabolism. In conclusion, the deficiency of the nuclear hormone receptor nhr-210 in alpha-synuclein expressing strain of C. elegans, results in altered mitochondrial function, coupled with alterations in vital metabolite levels. These findings underline the functional and physiological importance of nhr-210 enrichment in CEPsh glia.
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Affiliation(s)
- Rohil Hameed
- Division of Neuroscience and Ageing Biology, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, 226031, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Anam Naseer
- Division of Neuroscience and Ageing Biology, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, 226031, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Ankit Saxena
- Sophisticated Analytical Instrument Facility and Research, CSIR-Central Drug Research Institute, Lucknow, 226031, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Mahmood Akbar
- Division of Neuroscience and Ageing Biology, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, 226031, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Pranoy Toppo
- Division of Neuroscience and Ageing Biology, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, 226031, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Arunabh Sarkar
- Division of Neuroscience and Ageing Biology, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, 226031, India
| | - Sanjeev K Shukla
- Sophisticated Analytical Instrument Facility and Research, CSIR-Central Drug Research Institute, Lucknow, 226031, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Aamir Nazir
- Division of Neuroscience and Ageing Biology, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, 226031, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
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4
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Yadav DK, Chang AC, Grooms NWF, Chung SH, Gabel CV. O-GlcNAc signaling increases neuron regeneration through one-carbon metabolism in Caenorhabditis elegans. eLife 2024; 13:e86478. [PMID: 38334260 PMCID: PMC10857789 DOI: 10.7554/elife.86478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Accepted: 11/17/2023] [Indexed: 02/10/2024] Open
Abstract
Cellular metabolism plays an essential role in the regrowth and regeneration of a neuron following physical injury. Yet, our knowledge of the specific metabolic pathways that are beneficial to neuron regeneration remains sparse. Previously, we have shown that modulation of O-linked β-N-acetylglucosamine (O-GlcNAc) signaling, a ubiquitous post-translational modification that acts as a cellular nutrient sensor, can significantly enhance in vivo neuron regeneration. Here, we define the specific metabolic pathway by which O-GlcNAc transferase (ogt-1) loss of function mediates increased regenerative outgrowth. Performing in vivo laser axotomy and measuring subsequent regeneration of individual neurons in C. elegans, we find that glycolysis, serine synthesis pathway (SSP), one-carbon metabolism (OCM), and the downstream transsulfuration metabolic pathway (TSP) are all essential in this process. The regenerative effects of ogt-1 mutation are abrogated by genetic and/or pharmacological disruption of OCM and the SSP linking OCM to glycolysis. Testing downstream branches of this pathway, we find that enhanced regeneration is dependent only on the vitamin B12 independent shunt pathway. These results are further supported by RNA sequencing that reveals dramatic transcriptional changes by the ogt-1 mutation, in the genes involved in glycolysis, OCM, TSP, and ATP metabolism. Strikingly, the beneficial effects of the ogt-1 mutation can be recapitulated by simple metabolic supplementation of the OCM metabolite methionine in wild-type animals. Taken together, these data unearth the metabolic pathways involved in the increased regenerative capacity of a damaged neuron in ogt-1 animals and highlight the therapeutic possibilities of OCM and its related pathways in the treatment of neuronal injury.
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Affiliation(s)
- Dilip Kumar Yadav
- Department of Pharmacology, Physiology and Biophysics, Chobanian & Avedisian School of Medicine, Boston UniversityBostonUnited States
| | - Andrew C Chang
- Department of Pharmacology, Physiology and Biophysics, Chobanian & Avedisian School of Medicine, Boston UniversityBostonUnited States
| | - Noa WF Grooms
- Department of Bioengineering, Northeastern UniversityBostonUnited States
| | - Samuel H Chung
- Department of Bioengineering, Northeastern UniversityBostonUnited States
| | - Christopher V Gabel
- Department of Pharmacology, Physiology and Biophysics, Chobanian & Avedisian School of Medicine, Boston UniversityBostonUnited States
- Neurophotonics Center, Boston UniversityBostonUnited States
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5
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Paolillo VK, Ochs ME, Lundquist EA. MAB-5/Hox regulates the Q neuroblast transcriptome, including cwn-1/Wnt, to mediate posterior migration in Caenorhabditis elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.09.566461. [PMID: 37986999 PMCID: PMC10659417 DOI: 10.1101/2023.11.09.566461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Neurogenesis involves the precisely-coordinated action of genetic programs controlling large-scale neuronal fate specification down to terminal events of neuronal differentiation. The Q neuroblasts in C. elegans, QL on the left and QR on the right, divide, differentiate, and migrate in a similar pattern to produce three neurons each. However, QL on the left migrates posteriorly, and QR on the right migrates anteriorly. The MAB-5/Hox transcription factor is necessary and sufficient for posterior Q lineage migration, and is normally expressed only in the QL lineage. To define genes controlled by MAB-5 in the Q cells, fluorescence-activated cell sorting was utilized to isolate populations of Q cells at a time in early L1 larvae when MAB-5 first becomes active. Sorted Q cells from wild-type, mab-5 loss-of-function (lof), and mab-5 gain-of-function (gof) mutants were subject to RNA-seq and differential expression analysis. Genes enriched in Q cells included those involved in cell division, DNA replication, and DNA repair, consist with the neuroblast stem cell identity of the Q cells at this stage. Genes affected by mab-5 included those involved in neurogenesis, neural development, and interaction with the extracellular matrix. cwn-1, which encodes a Wnt signaling molecule, showed a paired response to mab-5 in the Q cells: cwn-1 expression was reduced in mab-5(lof) and increased in mab-5(gof), suggesting that MAB-5 is required for cwn-1 expression in Q cells. MAB-5 is required to prevent anterior migration of the Q lineage while it transcriptionally reprograms the Q lineage for posterior migration. Functional genetic analysis revealed that CWN-1 is required downstream of MAB-5 to inhibit anterior migration of the QL lineage, likely in parallel to EGL-20/Wnt in a non-canonical Wnt pathway. In sum, work here describes a Q cell transcriptome, and a set of genes regulated by MAB-5 in the QL lineage. One of these genes, cwn-1, acts downstream of mab-5 in QL migration, indicating that this gene set includes other genes utilized by MAB-5 to facilitate posterior neuroblast migration.
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Affiliation(s)
- Vitoria K Paolillo
- KU Center for Genomics, Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045
| | - Matthew E Ochs
- KU Center for Genomics, Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045
| | - Erik A Lundquist
- KU Center for Genomics, Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045
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6
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Heinze SD, Berger S, Engleitner S, Daube M, Hajnal A. Prolonging somatic cell proliferation through constitutive hox gene expression in C. elegans. Nat Commun 2023; 14:6850. [PMID: 37891160 PMCID: PMC10611754 DOI: 10.1038/s41467-023-42644-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 10/17/2023] [Indexed: 10/29/2023] Open
Abstract
hox genes encode a conserved family of homeodomain transcription factors that are essential to determine the identity of body segments during embryogenesis and maintain adult somatic stem cells competent to regenerate organs. In contrast to higher organisms, somatic cells in C. elegans irreversibly exit the cell cycle after completing their cell lineage and the adult soma cannot regenerate. Here, we show that hox gene expression levels in C. elegans determine the temporal competence of somatic cells to proliferate. Down-regulation of the central hox gene lin-39 in dividing vulval cells results in their premature cell cycle exit, whereas constitutive lin-39 expression causes precocious Pn.p cell and sex myoblast divisions and prolongs the proliferative phase of the vulval cells past their normal point of arrest. Furthermore, ectopic expression of hox genes in the quiescent anchor cell re-activates the cell cycle and induces proliferation until young adulthood. Thus, constitutive expression of a single hox transcription factor is sufficient to prolong somatic cell proliferation beyond the restriction imposed by the cell lineage. The down-regulation of hox gene expression in most somatic cells at the end of larval development may be one cause for the absence of cell proliferation in adult C. elegans.
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Affiliation(s)
- Svenia D Heinze
- Department of Molecular Life Sciences, University Zürich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
- Molecular Life Science PhD Program, University and ETH Zürich, CH-8057, Zürich, Switzerland
| | - Simon Berger
- Department of Molecular Life Sciences, University Zürich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
- Institute for Chemical- and Bioengineering, ETH Zürich, Vladimir Prelog Weg 1, 8093, Zürich, Switzerland
| | - Stefanie Engleitner
- Department of Molecular Life Sciences, University Zürich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
- Molecular Life Science PhD Program, University and ETH Zürich, CH-8057, Zürich, Switzerland
| | - Michael Daube
- Department of Molecular Life Sciences, University Zürich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
| | - Alex Hajnal
- Department of Molecular Life Sciences, University Zürich, Winterthurerstrasse 190, 8057, Zürich, Switzerland.
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7
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Weng JW, Park H, Valotteau C, Chen RT, Essmann CL, Pujol N, Sternberg PW, Chen CH. Body stiffness is a mechanical property that facilitates contact-mediated mate recognition in Caenorhabditis elegans. Curr Biol 2023; 33:3585-3596.e5. [PMID: 37541249 PMCID: PMC10530406 DOI: 10.1016/j.cub.2023.07.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 06/01/2023] [Accepted: 07/12/2023] [Indexed: 08/06/2023]
Abstract
Physical contact is prevalent in the animal kingdom to recognize suitable mates by decoding information about sex, species, and maturity. Although chemical cues for mate recognition have been extensively studied, the role of mechanical cues remains elusive. Here, we show that C. elegans males recognize conspecific and reproductive mates through short-range cues, and that the attractiveness of potential mates depends on the sex and developmental stages of the hypodermis. We find that a particular group of cuticular collagens is required for mate attractiveness. These collagens maintain body stiffness to sustain mate attractiveness but do not affect the surface properties that evoke the initial step of mate recognition, suggesting that males utilize multiple sensory mechanisms to recognize suitable mates. Manipulations of body stiffness via physical interventions, chemical treatments, and 3D-printed bionic worms indicate that body stiffness is a mechanical property for mate recognition and increases mating efficiency. Our study thus extends the repertoire of sensory cues of mate recognition in C. elegans and provides a paradigm to study the important roles of mechanosensory cues in social behaviors.
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Affiliation(s)
- Jen-Wei Weng
- Institute of Molecular and Cellular Biology, College of Life Science, National Taiwan University. No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Heenam Park
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E California Boulevard, Pasadena, CA 91125, USA
| | - Claire Valotteau
- Aix-Marseille Univ, INSERM, CNRS, LAI, Turing Centre for Living Systems, 163 Avenue de Luminy, 13009 Marseille, France
| | - Rui-Tsung Chen
- Institute of Molecular and Cellular Biology, College of Life Science, National Taiwan University. No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Clara L Essmann
- Bio3/Bioinformatics and Molecular Genetics, Albert-Ludwigs-University, Schaenzlestr. 1, 79104 Freiburg, Germany
| | - Nathalie Pujol
- Aix Marseille Univ, INSERM, CNRS, CIML, Turing Centre for Living Systems, 163 Avenue de Luminy, case 906, 13009 Marseille, France
| | - Paul W Sternberg
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E California Boulevard, Pasadena, CA 91125, USA.
| | - Chun-Hao Chen
- Institute of Molecular and Cellular Biology, College of Life Science, National Taiwan University. No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan; Division of Biology and Biological Engineering, California Institute of Technology, 1200 E California Boulevard, Pasadena, CA 91125, USA.
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8
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Roux AE, Yuan H, Podshivalova K, Hendrickson D, Kerr R, Kenyon C, Kelley D. Individual cell types in C. elegans age differently and activate distinct cell-protective responses. Cell Rep 2023; 42:112902. [PMID: 37531250 DOI: 10.1016/j.celrep.2023.112902] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 05/17/2023] [Accepted: 07/14/2023] [Indexed: 08/04/2023] Open
Abstract
Aging is characterized by a global decline in physiological function. However, by constructing a complete single-cell gene expression atlas, we find that Caenorhabditis elegans aging is not random in nature but instead is characterized by coordinated changes in functionally related metabolic, proteostasis, and stress-response genes in a cell-type-specific fashion, with downregulation of energy metabolism being the only nearly universal change. Similarly, the rates at which cells age differ significantly between cell types. In some cell types, aging is characterized by an increase in cell-to-cell variance, whereas in others, variance actually decreases. Remarkably, multiple resilience-enhancing transcription factors known to extend lifespan are activated across many cell types with age; we discovered new longevity candidates, such as GEI-3, among these. Together, our findings suggest that cells do not age passively but instead react strongly, and individualistically, to events that occur during aging. This atlas can be queried through a public interface.
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Affiliation(s)
| | - Han Yuan
- Calico Life Sciences LLC, South San Francisco, CA 94080, USA
| | | | | | - Rex Kerr
- Calico Life Sciences LLC, South San Francisco, CA 94080, USA
| | - Cynthia Kenyon
- Calico Life Sciences LLC, South San Francisco, CA 94080, USA.
| | - David Kelley
- Calico Life Sciences LLC, South San Francisco, CA 94080, USA.
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Hernando G, Turani O, Rodriguez Araujo N, Bouzat C. The diverse family of Cys-loop receptors in Caenorhabditis elegans: insights from electrophysiological studies. Biophys Rev 2023; 15:733-750. [PMID: 37681094 PMCID: PMC10480131 DOI: 10.1007/s12551-023-01080-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 06/18/2023] [Indexed: 09/09/2023] Open
Abstract
Cys-loop receptors integrate a large family of pentameric ligand-gated ion channels that mediate fast ionotropic responses in vertebrates and invertebrates. Their vital role in converting neurotransmitter recognition into an electrical impulse makes these receptors essential for a great variety of physiological processes. In vertebrates, the Cys-loop receptor family includes the cation-selective channels, nicotinic acetylcholine and 5-hydroxytryptamine type 3 receptors, and the anion-selective channels, GABAA and glycine receptors, whereas in invertebrates, the repertoire is significantly larger. The free-living nematode Caenorhabditis elegans has the largest known Cys-loop receptor family as well as unique receptors that are absent in vertebrates and constitute attractive targets for anthelmintic drugs. Given the large number and variety of Cys-loop receptor subunits and the multiple possible ways of subunit assembly, C. elegans offers a large diversity of receptors although only a limited number of them have been characterized to date. C. elegans has emerged as a powerful model for the study of the nervous system and human diseases as well as a model for antiparasitic drug discovery. This nematode has also shown promise in the pharmaceutical industry search for new therapeutic compounds. C. elegans is therefore a powerful model organism to explore the biology and pharmacology of Cys-loop receptors and their potential as targets for novel therapeutic interventions. In this review, we provide a comprehensive overview of what is known about the function of C. elegans Cys-loop receptors from an electrophysiological perspective.
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Affiliation(s)
- Guillermina Hernando
- Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Investigaciones Bioquímicas de Bahía Blanca, Camino La Carrindanga Km 7, 8000 Bahía Blanca, Argentina
| | - Ornella Turani
- Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Investigaciones Bioquímicas de Bahía Blanca, Camino La Carrindanga Km 7, 8000 Bahía Blanca, Argentina
| | - Noelia Rodriguez Araujo
- Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Investigaciones Bioquímicas de Bahía Blanca, Camino La Carrindanga Km 7, 8000 Bahía Blanca, Argentina
| | - Cecilia Bouzat
- Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Investigaciones Bioquímicas de Bahía Blanca, Camino La Carrindanga Km 7, 8000 Bahía Blanca, Argentina
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10
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Ghaddar A, Armingol E, Huynh C, Gevirtzman L, Lewis NE, Waterston R, O’Rourke EJ. Whole-body gene expression atlas of an adult metazoan. SCIENCE ADVANCES 2023; 9:eadg0506. [PMID: 37352352 PMCID: PMC10289653 DOI: 10.1126/sciadv.adg0506] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 05/17/2023] [Indexed: 06/25/2023]
Abstract
Gene activity defines cell identity, drives intercellular communication, and underlies the functioning of multicellular organisms. We present the single-cell resolution atlas of gene activity of a fertile adult metazoan: Caenorhabditis elegans. This compendium comprises 180 distinct cell types and 19,657 expressed genes. We predict 7541 transcription factor expression profile associations likely responsible for defining cellular identity. We predict thousands of intercellular interactions across the C. elegans body and the ligand-receptor pairs that mediate them, some of which we experimentally validate. We identify 172 genes that show consistent expression across cell types, are involved in basic and essential functions, and are conserved across phyla; therefore, we present them as experimentally validated housekeeping genes. We developed the WormSeq application to explore these data. In addition to the integrated gene-to-systems biology, we present genome-scale single-cell resolution testable hypotheses that we anticipate will advance our understanding of the molecular mechanisms, underlying the functioning of a multicellular organism and the perturbations that lead to its malfunction.
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Affiliation(s)
- Abbas Ghaddar
- Department of Biology, College of Arts and Sciences, University of Virginia, Charlottesville, VA 22903, USA
| | - Erick Armingol
- Bioinformatics and Systems Biology Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Chau Huynh
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Louis Gevirtzman
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Nathan E. Lewis
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Robert Waterston
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Eyleen J. O’Rourke
- Department of Biology, College of Arts and Sciences, University of Virginia, Charlottesville, VA 22903, USA
- Department of Cell Biology, University of Virginia School of Medicine, Charlottesville, VA 22903, USA
- Robert M. Berne Cardiovascular Research Center, School of Medicine, University of Virginia, Charlottesville, VA 22903, USA
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11
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Costa DS, Kenny-Ganzert IW, Chi Q, Park K, Kelley LC, Garde A, Matus DQ, Park J, Yogev S, Goldstein B, Gibney TV, Pani AM, Sherwood DR. The Caenorhabditis elegans anchor cell transcriptome: ribosome biogenesis drives cell invasion through basement membrane. Development 2023; 150:dev201570. [PMID: 37039075 PMCID: PMC10259517 DOI: 10.1242/dev.201570] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 03/27/2023] [Indexed: 04/12/2023]
Abstract
Cell invasion through basement membrane (BM) barriers is important in development, immune function and cancer progression. As invasion through BM is often stochastic, capturing gene expression profiles of actively invading cells in vivo remains elusive. Using the stereotyped timing of Caenorhabditis elegans anchor cell (AC) invasion, we generated an AC transcriptome during BM breaching. Through a focused RNAi screen of transcriptionally enriched genes, we identified new invasion regulators, including translationally controlled tumor protein (TCTP). We also discovered gene enrichment of ribosomal proteins. AC-specific RNAi, endogenous ribosome labeling and ribosome biogenesis analysis revealed that a burst of ribosome production occurs shortly after AC specification, which drives the translation of proteins mediating BM removal. Ribosomes also enrich near the AC endoplasmic reticulum (ER) Sec61 translocon and the endomembrane system expands before invasion. We show that AC invasion is sensitive to ER stress, indicating a heightened requirement for translation of ER-trafficked proteins. These studies reveal key roles for ribosome biogenesis and endomembrane expansion in cell invasion through BM and establish the AC transcriptome as a resource to identify mechanisms underlying BM transmigration.
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Affiliation(s)
- Daniel S. Costa
- Department of Biology, Duke University, Box 90338, Durham, NC 27708, USA
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27708, USA
| | | | - Qiuyi Chi
- Department of Biology, Duke University, Box 90338, Durham, NC 27708, USA
| | - Kieop Park
- Department of Biology, Duke University, Box 90338, Durham, NC 27708, USA
| | - Laura C. Kelley
- Department of Biology, Duke University, Box 90338, Durham, NC 27708, USA
| | - Aastha Garde
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
- Howard Hughes Medical Institute, Princeton University, Princeton, NJ 08544, USA
| | - David Q. Matus
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Junhyun Park
- Department of Neuroscience, Yale School of Medicine, New Haven, CT 06510, USA
| | - Shaul Yogev
- Department of Neuroscience, Yale School of Medicine, New Haven, CT 06510, USA
| | - Bob Goldstein
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Theresa V. Gibney
- Department of Biology, University of Virginia, Charlottesville, VA 29903, USA
| | - Ariel M. Pani
- Department of Biology, University of Virginia, Charlottesville, VA 29903, USA
- Department of Cell Biology, University of Virginia School of Medicine, Charlottesville, VA 29904, USA
| | - David R. Sherwood
- Department of Biology, Duke University, Box 90338, Durham, NC 27708, USA
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12
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Seidenthal M, Jánosi B, Rosenkranz N, Schuh N, Elvers N, Willoughby M, Zhao X, Gottschalk A. pOpsicle: An all-optical reporter system for synaptic vesicle recycling combining pH-sensitive fluorescent proteins with optogenetic manipulation of neuronal activity. Front Cell Neurosci 2023; 17:1120651. [PMID: 37066081 PMCID: PMC10102542 DOI: 10.3389/fncel.2023.1120651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Accepted: 03/15/2023] [Indexed: 04/03/2023] Open
Abstract
pH-sensitive fluorescent proteins are widely used to study synaptic vesicle (SV) fusion and recycling. When targeted to the lumen of SVs, fluorescence of these proteins is quenched by the acidic pH. Following SV fusion, they are exposed to extracellular neutral pH, resulting in a fluorescence increase. SV fusion, recycling and acidification can thus be tracked by tagging integral SV proteins with pH-sensitive proteins. Neurotransmission is generally activated by electrical stimulation, which is not feasible in small, intact animals. Previous in vivo approaches depended on distinct (sensory) stimuli, thus limiting the addressable neuron types. To overcome these limitations, we established an all-optical approach to stimulate and visualize SV fusion and recycling. We combined distinct pH-sensitive fluorescent proteins (inserted into the SV protein synaptogyrin) and light-gated channelrhodopsins (ChRs) for optical stimulation, overcoming optical crosstalk and thus enabling an all-optical approach. We generated two different variants of the pH-sensitive optogenetic reporter of vesicle recycling (pOpsicle) and tested them in cholinergic neurons of intact Caenorhabditis elegans nematodes. First, we combined the red fluorescent protein pHuji with the blue-light gated ChR2(H134R), and second, the green fluorescent pHluorin combined with the novel red-shifted ChR ChrimsonSA. In both cases, fluorescence increases were observed after optical stimulation. Increase and subsequent decline of fluorescence was affected by mutations of proteins involved in SV fusion and endocytosis. These results establish pOpsicle as a non-invasive, all-optical approach to investigate different steps of the SV cycle.
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Affiliation(s)
- Marius Seidenthal
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt, Germany
- Institute of Biophysical Chemistry, Department of Biochemistry, Chemistry and Pharmacy, Goethe University, Frankfurt, Germany
| | - Barbara Jánosi
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt, Germany
- Institute of Biophysical Chemistry, Department of Biochemistry, Chemistry and Pharmacy, Goethe University, Frankfurt, Germany
| | - Nils Rosenkranz
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt, Germany
- Institute of Biophysical Chemistry, Department of Biochemistry, Chemistry and Pharmacy, Goethe University, Frankfurt, Germany
| | - Noah Schuh
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt, Germany
- Institute of Biophysical Chemistry, Department of Biochemistry, Chemistry and Pharmacy, Goethe University, Frankfurt, Germany
| | - Nora Elvers
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt, Germany
- Institute of Biophysical Chemistry, Department of Biochemistry, Chemistry and Pharmacy, Goethe University, Frankfurt, Germany
| | - Miles Willoughby
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt, Germany
- Institute of Biophysical Chemistry, Department of Biochemistry, Chemistry and Pharmacy, Goethe University, Frankfurt, Germany
| | - Xinda Zhao
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt, Germany
- Institute of Biophysical Chemistry, Department of Biochemistry, Chemistry and Pharmacy, Goethe University, Frankfurt, Germany
| | - Alexander Gottschalk
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt, Germany
- Institute of Biophysical Chemistry, Department of Biochemistry, Chemistry and Pharmacy, Goethe University, Frankfurt, Germany
- *Correspondence: Alexander Gottschalk,
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13
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Kropp PA, Rogers P, Kelly SE, McWhirter R, Goff WD, Levitan IM, Miller DM, Golden A. Patient-specific variants of NFU1/NFU-1 disrupt cholinergic signaling in a model of multiple mitochondrial dysfunctions syndrome 1. Dis Model Mech 2023; 16:286662. [PMID: 36645076 PMCID: PMC9922734 DOI: 10.1242/dmm.049594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 01/05/2023] [Indexed: 01/17/2023] Open
Abstract
Neuromuscular dysfunction is a common feature of mitochondrial diseases and frequently presents as ataxia, spasticity and/or dystonia, all of which can severely impact individuals with mitochondrial diseases. Dystonia is one of the most common symptoms of multiple mitochondrial dysfunctions syndrome 1 (MMDS1), a disease associated with mutations in the causative gene (NFU1) that impair iron-sulfur cluster biogenesis. We have generated Caenorhabditis elegans strains that recreated patient-specific point variants in the C. elegans ortholog (nfu-1) that result in allele-specific dysfunction. Each of these mutants, Gly147Arg and Gly166Cys, have altered acetylcholine signaling at neuromuscular junctions, but opposite effects on activity and motility. We found that the Gly147Arg variant was hypersensitive to acetylcholine and that knockdown of acetylcholine release rescued nearly all neuromuscular phenotypes of this variant. In contrast, we found that the Gly166Cys variant caused predominantly postsynaptic acetylcholine hypersensitivity due to an unclear mechanism. These results are important for understanding the neuromuscular conditions of MMDS1 patients and potential avenues for therapeutic intervention.
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Affiliation(s)
- Peter A Kropp
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.,Biology Department, Kenyon College, Gambier, OH 43022, USA
| | - Philippa Rogers
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sydney E Kelly
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Rebecca McWhirter
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37235, USA
| | - Willow D Goff
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.,Biology Department, Colgate University, Hamilton, NY 13346, USA
| | - Ian M Levitan
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - David M Miller
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37235, USA.,Neuroscience Graduate Program, Vanderbilt University, Nashville, TN 37235, USA
| | - Andy Golden
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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14
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Abstract
We study microvilli of Caenorhabditis elegans larvae and mouse intestinal tissues by combining high-pressure freezing, cryo-focused ion-beam milling, cryo-electron tomography, and subtomogram averaging. We find that many radial nanometer bristles, referred to as nanobristles, project from the lateral surface of nematode and mouse microvilli. The C. elegans nanobristles are 37.5 nm long. We show that nanobristle formation requires a protocadherin family protein, CDH-8, in C. elegans. The loss of nanobristles in cdh-8 mutants slows down animal growth and ectopically increases the number of Y-shaped microvilli, the putative intermediate structures if microvilli split from their tips. Our results reveal a potential role of nanobristles in separating microvilli and suggest that microvilli division may help generate nascent microvilli with uniformity. Microvilli are actin-bundle-supported membrane protrusions essential for absorption, secretion, and sensation. Microvilli defects cause gastrointestinal disorders; however, mechanisms controlling microvilli formation and organization remain unresolved. Here, we study microvilli by vitrifying the Caenorhabditis elegans larvae and mouse intestinal tissues with high-pressure freezing, thinning them with cryo-focused ion-beam milling, followed by cryo-electron tomography and subtomogram averaging. We find that many radial nanometer bristles referred to as nanobristles project from the lateral surface of nematode and mouse microvilli. The C. elegans nanobristles are 37.5 nm long and 4.5 nm wide. Nanobristle formation requires a protocadherin family protein, CDH-8, in C. elegans. The loss of nanobristles in cdh-8 mutants slows down animal growth and ectopically increases the number of Y-shaped microvilli, the putative intermediate structures if microvilli split from tips. Our results reveal a potential role of nanobristles in separating microvilli and suggest that microvilli division may help generate nascent microvilli with uniformity.
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15
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Abstract
Cleavage under targets and release using nuclease (CUT&RUN) is a recently developed chromatin profiling technique that uses a targeted micrococcal nuclease cleavage strategy to obtain high-resolution binding profiles of protein factors or to map histones with specific post-translational modifications. Due to its high sensitivity, CUT&RUN allows quality binding profiles to be obtained with only a fraction of the starting material and sequencing depth typically required for other chromatin profiling techniques such as chromatin immunoprecipitation. Although CUT&RUN has been widely adopted in multiple model systems, it has rarely been utilized in Caenorhabditis elegans, a model system of great importance to genomic research. Cell dissociation techniques, which are required for this approach, can be challenging in C. elegans due to the toughness of the worm's cuticle and the sensitivity of the cells themselves. Here, we describe a robust CUT&RUN protocol for use in C. elegans to determine the genome-wide localization of protein factors and specific histone marks. With a simple protocol utilizing live, uncrosslinked tissue as the starting material, performing CUT&RUN in worms has the potential to produce physiologically relevant data at a higher resolution than chromatin immunoprecipitation. This protocol involves a simple dissociation step to uniformly permeabilize worms while avoiding sample loss or cell damage, resulting in high-quality CUT&RUN profiles with as few as 100 worms and detectable signal with as few as 10 worms. This represents a significant advancement over chromatin immunoprecipitation, which typically uses thousands or hundreds of thousands of worms for a single experiment. The protocols presented here provide a detailed description of worm growth, sample preparation, CUT&RUN workflow, library preparation for high-throughput sequencing, and a basic overview of data analysis, making CUT&RUN simple and accessible for any worm lab. © 2022 Wiley Periodicals LLC. Basic Protocol 1: Growth and synchronization of C. elegans Basic Protocol 2: Worm dissociation, sample preparation, and optimization Basic Protocol 3: CUT&RUN chromatin profiling Alternate Protocol: Improving CUT&RUN signal using a secondary antibody Basic Protocol 4: CUT&RUN library preparation for Illumina high-throughput sequencing Basic Protocol 5: Basic data analysis using Linux.
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Affiliation(s)
- Felicity J. Emerson
- Department of Molecular Biology and Genetics, Cornell
University, Ithaca, NY, 14850
- Biomedical and Biological Sciences Ph.D. Program, Cornell
University, Ithaca, NY, 14850
| | - Siu Sylvia Lee
- Department of Molecular Biology and Genetics, Cornell
University, Ithaca, NY, 14850
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16
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Woronik A, Kiontke K, Jallad RS, Herrera RA, Fitch DHA. Laser Microdissection for Species-Agnostic Single-Tissue Applications. J Vis Exp 2022:10.3791/63666. [PMID: 35435919 PMCID: PMC9976942 DOI: 10.3791/63666] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Single-cell methodologies have revolutionized the analysis of the transcriptomes of specific cell types. However, they often require species-specific genetic "toolkits," such as promoters driving tissue-specific expression of fluorescent proteins. Further, protocols that disrupt tissues to isolate individual cells remove cells from their native environment (e.g., signaling from neighbors) and may result in stress responses or other differences from native gene expression states. In the present protocol, laser microdissection (LMD) is optimized to isolate individual nematode tail tips for the study of gene expression during male tail tip morphogenesis. LMD allows the isolation of a portion of the animal without the need for cellular disruption or species-specific toolkits and is thus applicable to any species. Subsequently, single-cell RNA-seq library preparation protocols such as CEL-Seq2 can be applied to LMD-isolated single tissues and analyzed using standard pipelines, given that a well-annotated genome or transcriptome is available for the species. Such data can be used to establish how conserved or different the transcriptomes are that underlie the development of that tissue in different species. Limitations include the ability to cut out the tissue of interest and the sample size. A power analysis shows that as few as 70 tail tips per condition are required for 80% power. Tight synchronization of development is needed to obtain this number of animals at the same developmental stage. Thus, a method to synchronize animals at 1 h intervals is also described.
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Affiliation(s)
- Alyssa Woronik
- Center for Developmental Genetics, New York University,Sacred Heart University
| | - Karin Kiontke
- Center for Developmental Genetics, New York University
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17
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Wang X, Jiang Q, Song Y, He Z, Zhang H, Song M, Zhang X, Dai Y, Karalay O, Dieterich C, Antebi A, Wu L, Han JJ, Shen Y. Ageing induces tissue‐specific transcriptomic changes in
Caenorhabditis elegans. EMBO J 2022; 41:e109633. [PMID: 35253240 PMCID: PMC9016346 DOI: 10.15252/embj.2021109633] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 02/11/2022] [Accepted: 02/15/2022] [Indexed: 11/09/2022] Open
Abstract
Ageing is a complex process with common and distinct features across tissues. Unveiling the underlying processes driving ageing in individual tissues is indispensable to decipher the mechanisms of organismal longevity. Caenorhabditis elegans is a well‐established model organism that has spearheaded ageing research with the discovery of numerous genetic pathways controlling its lifespan. However, it remains challenging to dissect the ageing of worm tissues due to the limited description of tissue pathology and access to tissue‐specific molecular changes during ageing. In this study, we isolated cells from five major tissues in young and old worms and profiled the age‐induced transcriptomic changes within these tissues. We observed a striking diversity of ageing across tissues and identified different sets of longevity regulators therein. In addition, we found novel tissue‐specific factors, including irx‐1 and myrf‐2, which control the integrity of the intestinal barrier and sarcomere structure during ageing respectively. This study demonstrates the complexity of ageing across worm tissues and highlights the power of tissue‐specific transcriptomic profiling during ageing, which can serve as a resource to the field.
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Affiliation(s)
- Xueqing Wang
- State Key Laboratory of Cell Biology Shanghai Institute of Biochemistry and Cell Biology Center for Excellence in Molecular Cell Science Chinese Academy of Sciences Shanghai China
- University of Chinese Academy of Sciences Beijing China
| | - Quanlong Jiang
- CAS Key Laboratory of Computational Biology Shanghai Institute of Nutrition and Health, Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai China
- Peking‐Tsinghua Center for Life Sciences Academy for Advanced Interdisciplinary Studies, Center for Quantitative Biology (CQB) Peking University Beijing China
| | - Yuanyuan Song
- State Key Laboratory of Cell Biology Shanghai Institute of Biochemistry and Cell Biology Center for Excellence in Molecular Cell Science Chinese Academy of Sciences Shanghai China
- University of Chinese Academy of Sciences Beijing China
| | - Zhidong He
- State Key Laboratory of Cell Biology Shanghai Institute of Biochemistry and Cell Biology Center for Excellence in Molecular Cell Science Chinese Academy of Sciences Shanghai China
- University of Chinese Academy of Sciences Beijing China
| | - Hongdao Zhang
- State Key Laboratory of Cell Biology Shanghai Institute of Biochemistry and Cell Biology Center for Excellence in Molecular Cell Science Chinese Academy of Sciences Shanghai China
- University of Chinese Academy of Sciences Beijing China
| | - Mengjiao Song
- State Key Laboratory of Cell Biology Shanghai Institute of Biochemistry and Cell Biology Center for Excellence in Molecular Cell Science Chinese Academy of Sciences Shanghai China
- University of Chinese Academy of Sciences Beijing China
| | - Xiaona Zhang
- State Key Laboratory of Cell Biology Shanghai Institute of Biochemistry and Cell Biology Center for Excellence in Molecular Cell Science Chinese Academy of Sciences Shanghai China
- University of Chinese Academy of Sciences Beijing China
| | - Yumin Dai
- State Key Laboratory of Cell Biology Shanghai Institute of Biochemistry and Cell Biology Center for Excellence in Molecular Cell Science Chinese Academy of Sciences Shanghai China
- University of Chinese Academy of Sciences Beijing China
| | - Oezlem Karalay
- Max Planck Institute for Biology of Ageing Cologne Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging‐Associated Diseases (CECAD) University of Cologne Cologne Germany
| | - Christoph Dieterich
- Klaus Tschira Institute for Integrative Computational Cardiology and Department of Internal Medicine III University Hospital Heidelberg Heidelberg Germany
| | - Adam Antebi
- Max Planck Institute for Biology of Ageing Cologne Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging‐Associated Diseases (CECAD) University of Cologne Cologne Germany
| | - Ligang Wu
- State Key Laboratory of Cell Biology Shanghai Institute of Biochemistry and Cell Biology Center for Excellence in Molecular Cell Science Chinese Academy of Sciences Shanghai China
- University of Chinese Academy of Sciences Beijing China
| | - Jing‐Dong J Han
- CAS Key Laboratory of Computational Biology Shanghai Institute of Nutrition and Health, Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai China
- Peking‐Tsinghua Center for Life Sciences Academy for Advanced Interdisciplinary Studies, Center for Quantitative Biology (CQB) Peking University Beijing China
| | - Yidong Shen
- State Key Laboratory of Cell Biology Shanghai Institute of Biochemistry and Cell Biology Center for Excellence in Molecular Cell Science Chinese Academy of Sciences Shanghai China
- University of Chinese Academy of Sciences Beijing China
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18
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Liang X, Calovich-Benne C, Norris A. Sensory neuron transcriptomes reveal complex neuron-specific function and regulation of mec-2/Stomatin splicing. Nucleic Acids Res 2021; 50:2401-2416. [PMID: 34875684 PMCID: PMC8934639 DOI: 10.1093/nar/gkab1134] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 09/30/2021] [Accepted: 11/09/2021] [Indexed: 12/16/2022] Open
Abstract
The function and identity of a cell is shaped by transcription factors controlling transcriptional networks, and further shaped by RNA binding proteins controlling post-transcriptional networks. To overcome limitations inherent to analysis of sparse single-cell post-transcriptional data, we leverage the invariant Caenorhabditis elegans cell lineage, isolating thousands of identical neuron types from thousands of isogenic individuals. The resulting deep transcriptomes facilitate splicing network analysis due to increased sequencing depth and uniformity. We focus on mechanosensory touch-neuron splicing regulated by MEC-8/RBPMS. We identify a small MEC-8-regulated network, where MEC-8 establishes touch-neuron isoforms differing from default isoforms found in other cells. MEC-8 establishes the canonical long mec-2/Stomatin isoform in touch neurons, but surprisingly the non-canonical short isoform predominates in other neurons, including olfactory neurons, and mec-2 is required for olfaction. Forced endogenous isoform-specific expression reveals that the short isoform functions in olfaction but not mechanosensation. The long isoform is functional in both processes. Remarkably, restoring the long isoform completely rescues mec-8 mutant mechanosensation, indicating a single MEC-8 touch-neuron target is phenotypically relevant. Within the long isoform we identify a cassette exon further diversifying mec-2 into long/extra-long isoforms. Neither is sufficient for mechanosensation. Both are simultaneously required, likely functioning as heteromers to mediate mechanosensation.
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Affiliation(s)
- Xiaoyu Liang
- Southern Methodist University, Dallas, TX 75275, USA
| | | | - Adam Norris
- Southern Methodist University, Dallas, TX 75275, USA
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19
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Cao D. Reverse complementary matches simultaneously promote both back-splicing and exon-skipping. BMC Genomics 2021; 22:586. [PMID: 34344317 PMCID: PMC8330042 DOI: 10.1186/s12864-021-07910-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 07/23/2021] [Indexed: 12/24/2022] Open
Abstract
Background Circular RNAs (circRNAs) play diverse roles in different biological and physiological environments and are always expressed in a tissue-specific manner. Especially, circRNAs are enriched in the brain tissues of almost all investigated species, including humans, mice, Drosophila, etc. Although circRNAs were found in C. elegans, the neuron-specific circRNA data is not available yet. Exon-skipping is found to be correlated to circRNA formation, but the mechanisms that link them together are not clear. Results Here, through large-scale neuron isolation from the first larval (L1) stage of C. elegans followed by RNA sequencing with ribosomal RNA depletion, the neuronal circRNA data in C. elegans were obtained. Hundreds of novel circRNAs were annotated with high accuracy. circRNAs were highly expressed in the neurons of C. elegans and were positively correlated to the levels of their cognate linear mRNAs. Disruption of reverse complementary match (RCM) sequences in circRNA flanking introns effectively abolished circRNA formation. In the zip-2 gene, deletion of either upstream or downstream RCMs almost eliminated the production of both the circular and the skipped transcript. Interestingly, the 13-nt RCM in zip-2 is highly conserved across five nematode ortholog genes, which show conserved exon-skipping patterns. Finally, through in vivo one-by-one mutagenesis of all the splicing sites and branch points required for exon-skipping and back-splicing in the zip-2 gene, I showed that back-splicing still happened without exon-skipping, and vice versa. Conclusions Through protocol optimization, total RNA obtained from sorted neurons is increased to hundreds of nanograms. circRNAs highly expressed in the neurons of C. elegans are more likely to be derived from genes also highly expressed in the neurons. RCMs are abundant in circRNA flanking introns, and RCM-deletion is an efficient way to knockout circRNAs. More importantly, these RCMs are not only required for back-splicing but also promote the skipping of exon(s) to be circularized. Finally, RCMs in circRNA flanking introns can directly promote both exon-skipping and back-splicing, providing a new explanation for the correlation between them. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-07910-w.
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Affiliation(s)
- Dong Cao
- Information Processing Biology Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna, Kunigami, 904-0495, Okinawa, Japan.
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20
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Taylor SR, Santpere G, Weinreb A, Barrett A, Reilly MB, Xu C, Varol E, Oikonomou P, Glenwinkel L, McWhirter R, Poff A, Basavaraju M, Rafi I, Yemini E, Cook SJ, Abrams A, Vidal B, Cros C, Tavazoie S, Sestan N, Hammarlund M, Hobert O, Miller DM. Molecular topography of an entire nervous system. Cell 2021; 184:4329-4347.e23. [PMID: 34237253 DOI: 10.1016/j.cell.2021.06.023] [Citation(s) in RCA: 274] [Impact Index Per Article: 91.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 04/09/2021] [Accepted: 06/14/2021] [Indexed: 02/08/2023]
Abstract
We have produced gene expression profiles of all 302 neurons of the C. elegans nervous system that match the single-cell resolution of its anatomy and wiring diagram. Our results suggest that individual neuron classes can be solely identified by combinatorial expression of specific gene families. For example, each neuron class expresses distinct codes of ∼23 neuropeptide genes and ∼36 neuropeptide receptors, delineating a complex and expansive "wireless" signaling network. To demonstrate the utility of this comprehensive gene expression catalog, we used computational approaches to (1) identify cis-regulatory elements for neuron-specific gene expression and (2) reveal adhesion proteins with potential roles in process placement and synaptic specificity. Our expression data are available at https://cengen.org and can be interrogated at the web application CengenApp. We expect that this neuron-specific directory of gene expression will spur investigations of underlying mechanisms that define anatomy, connectivity, and function throughout the C. elegans nervous system.
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Affiliation(s)
- Seth R Taylor
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Gabriel Santpere
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA; Neurogenomics Group, Research Programme on Biomedical Informatics (GRIB), Hospital del Mar Medical Research Institute (IMIM), DCEXS, Universitat Pompeu Fabra, 08003 Barcelona, Catalonia, Spain
| | - Alexis Weinreb
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA; Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
| | - Alec Barrett
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA; Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
| | - Molly B Reilly
- Department of Biological Sciences, Columbia University, New York, NY, USA; Howard Hughes Medical Institute, Columbia University, New York, NY, USA
| | - Chuan Xu
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA
| | - Erdem Varol
- Department of Statistics, Columbia University, New York, NY, USA
| | - Panos Oikonomou
- Department of Biological Sciences, Columbia University, New York, NY, USA; Department of Systems Biology, Columbia University Medical Center, New York, NY, USA
| | - Lori Glenwinkel
- Department of Biological Sciences, Columbia University, New York, NY, USA; Howard Hughes Medical Institute, Columbia University, New York, NY, USA
| | - Rebecca McWhirter
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Abigail Poff
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Manasa Basavaraju
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA; Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
| | - Ibnul Rafi
- Department of Biological Sciences, Columbia University, New York, NY, USA; Howard Hughes Medical Institute, Columbia University, New York, NY, USA
| | - Eviatar Yemini
- Department of Biological Sciences, Columbia University, New York, NY, USA; Howard Hughes Medical Institute, Columbia University, New York, NY, USA
| | - Steven J Cook
- Department of Biological Sciences, Columbia University, New York, NY, USA; Howard Hughes Medical Institute, Columbia University, New York, NY, USA
| | - Alexander Abrams
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA; Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
| | - Berta Vidal
- Department of Biological Sciences, Columbia University, New York, NY, USA; Howard Hughes Medical Institute, Columbia University, New York, NY, USA
| | - Cyril Cros
- Department of Biological Sciences, Columbia University, New York, NY, USA; Howard Hughes Medical Institute, Columbia University, New York, NY, USA
| | - Saeed Tavazoie
- Department of Biological Sciences, Columbia University, New York, NY, USA; Department of Systems Biology, Columbia University Medical Center, New York, NY, USA
| | - Nenad Sestan
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA
| | - Marc Hammarlund
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA; Department of Genetics, Yale University School of Medicine, New Haven, CT, USA.
| | - Oliver Hobert
- Department of Biological Sciences, Columbia University, New York, NY, USA; Howard Hughes Medical Institute, Columbia University, New York, NY, USA.
| | - David M Miller
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA; Program in Neuroscience, Vanderbilt University School of Medicine, Nashville, TN, USA.
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21
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Bouvrais H, Chesneau L, Le Cunff Y, Fairbrass D, Soler N, Pastezeur S, Pécot T, Kervrann C, Pécréaux J. The coordination of spindle-positioning forces during the asymmetric division of the Caenorhabditis elegans zygote. EMBO Rep 2021; 22:e50770. [PMID: 33900015 DOI: 10.15252/embr.202050770] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 02/22/2021] [Accepted: 03/03/2021] [Indexed: 12/28/2022] Open
Abstract
In Caenorhabditis elegans zygote, astral microtubules generate forces essential to position the mitotic spindle, by pushing against and pulling from the cortex. Measuring microtubule dynamics there, we revealed the presence of two populations, corresponding to pulling and pushing events. It offers a unique opportunity to study, under physiological conditions, the variations of both spindle-positioning forces along space and time. We propose a threefold control of pulling force, by polarity, spindle position and mitotic progression. We showed that the sole anteroposterior asymmetry in dynein on-rate, encoding pulling force imbalance, is sufficient to cause posterior spindle displacement. The positional regulation, reflecting the number of microtubule contacts in the posterior-most region, reinforces this imbalance only in late anaphase. Furthermore, we exhibited the first direct proof that dynein processivity increases along mitosis. It reflects the temporal control of pulling forces, which strengthens at anaphase onset following mitotic progression and independently from chromatid separation. In contrast, the pushing force remains constant and symmetric and contributes to maintaining the spindle at the cell centre during metaphase.
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Affiliation(s)
| | | | - Yann Le Cunff
- CNRS, IGDR - UMR 6290, University of Rennes, Rennes, France
| | | | - Nina Soler
- CNRS, IGDR - UMR 6290, University of Rennes, Rennes, France
| | | | - Thierry Pécot
- INRIA, Centre Rennes - Bretagne Atlantique, Rennes, France
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22
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Barrett A, McWhirter R, Taylor SR, Weinreb A, Miller DM, Hammarlund M. A head-to-head comparison of ribodepletion and polyA selection approaches for C. elegans low input RNA-sequencing libraries. G3-GENES GENOMES GENETICS 2021; 11:6226485. [PMID: 33856427 PMCID: PMC8495925 DOI: 10.1093/g3journal/jkab121] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 03/25/2021] [Indexed: 12/18/2022]
Abstract
A recent and powerful technique is to obtain transcriptomes from rare cell populations, such as single neurons in Caenorhabditis elegans, by enriching dissociated cells using fluorescent sorting. However, these cell samples often have low yields of RNA that present challenges in library preparation. This can lead to PCR duplicates, noisy gene expression for lowly expressed genes, and other issues that limit endpoint analysis. Furthermore, some common resources, such as sequence-specific kits for removing ribosomal RNA, are not optimized for nonmammalian samples. To advance library construction for such challenging samples, we compared two approaches for building RNAseq libraries from less than 10 nanograms of C. elegans RNA: SMARTSeq V4 (Takara), a widely used kit for selecting poly-adenylated transcripts; and SoLo Ovation (Tecan Genomics), a newly developed ribodepletion-based approach. For ribodepletion, we used a custom kit of 200 probes designed to match C. elegans rRNA gene sequences. We found that SoLo Ovation, in combination with our custom C. elegans probe set for rRNA depletion, detects an expanded set of noncoding RNAs, shows reduced noise in lowly expressed genes, and more accurately counts expression of long genes. The approach described here should be broadly useful for similar efforts to analyze transcriptomics when RNA is limiting.
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Affiliation(s)
- Alec Barrett
- Department of Genetics, Yale University School of Medicine, New Haven, CT, 06510, USA
| | - Rebecca McWhirter
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Seth R Taylor
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Alexis Weinreb
- Department of Genetics, Yale University School of Medicine, New Haven, CT, 06510, USA.,Department of Neuroscience, Yale University School of Medicine, New Haven, CT, 06510, USA
| | - David M Miller
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA.,Program in Neuroscience, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Marc Hammarlund
- Department of Genetics, Yale University School of Medicine, New Haven, CT, 06510, USA.,Department of Neuroscience, Yale University School of Medicine, New Haven, CT, 06510, USA
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23
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Ben-David E, Boocock J, Guo L, Zdraljevic S, Bloom JS, Kruglyak L. Whole-organism eQTL mapping at cellular resolution with single-cell sequencing. eLife 2021; 10:e65857. [PMID: 33734084 PMCID: PMC8062134 DOI: 10.7554/elife.65857] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 03/17/2021] [Indexed: 12/11/2022] Open
Abstract
Genetic regulation of gene expression underlies variation in disease risk and other complex traits. The effect of expression quantitative trait loci (eQTLs) varies across cell types; however, the complexity of mammalian tissues makes studying cell-type eQTLs highly challenging. We developed a novel approach in the model nematode Caenorhabditis elegans that uses single-cell RNA sequencing to map eQTLs at cellular resolution in a single one-pot experiment. We mapped eQTLs across cell types in an extremely large population of genetically distinct C. elegans individuals. We found cell-type-specific trans eQTL hotspots that affect the expression of core pathways in the relevant cell types. Finally, we found single-cell-specific eQTL effects in the nervous system, including an eQTL with opposite effects in two individual neurons. Our results show that eQTL effects can be specific down to the level of single cells.
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Affiliation(s)
- Eyal Ben-David
- Department of Human Genetics, Department of Biological Chemistry, and Howard Hughes Medical Institute, University of California, Los AngelesLos AngelesUnited States
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, The Hebrew University School of MedicineJerusalemIsrael
| | - James Boocock
- Department of Human Genetics, Department of Biological Chemistry, and Howard Hughes Medical Institute, University of California, Los AngelesLos AngelesUnited States
| | - Longhua Guo
- Department of Human Genetics, Department of Biological Chemistry, and Howard Hughes Medical Institute, University of California, Los AngelesLos AngelesUnited States
| | - Stefan Zdraljevic
- Department of Human Genetics, Department of Biological Chemistry, and Howard Hughes Medical Institute, University of California, Los AngelesLos AngelesUnited States
| | - Joshua S Bloom
- Department of Human Genetics, Department of Biological Chemistry, and Howard Hughes Medical Institute, University of California, Los AngelesLos AngelesUnited States
| | - Leonid Kruglyak
- Department of Human Genetics, Department of Biological Chemistry, and Howard Hughes Medical Institute, University of California, Los AngelesLos AngelesUnited States
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24
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H3K9me selectively blocks transcription factor activity and ensures differentiated tissue integrity. Nat Cell Biol 2021; 23:1163-1175. [PMID: 34737442 PMCID: PMC8572725 DOI: 10.1038/s41556-021-00776-w] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 09/17/2021] [Indexed: 01/05/2023]
Abstract
The developmental role of histone H3K9 methylation (H3K9me), which typifies heterochromatin, remains unclear. In Caenorhabditis elegans, loss of H3K9me leads to a highly divergent upregulation of genes with tissue and developmental-stage specificity. During development H3K9me is lost from differentiated cell type-specific genes and gained at genes expressed in earlier developmental stages or other tissues. The continuous deposition of H3K9me2 by the SETDB1 homolog MET-2 after terminal differentiation is necessary to maintain repression. In differentiated tissues, H3K9me ensures silencing by restricting the activity of a defined set of transcription factors at promoters and enhancers. Increased chromatin accessibility following the loss of H3K9me is neither sufficient nor necessary to drive transcription. Increased ATAC-seq signal and gene expression correlate at a subset of loci positioned away from the nuclear envelope, while derepressed genes at the nuclear periphery remain poorly accessible despite being transcribed. In conclusion, H3K9me deposition can confer tissue-specific gene expression and maintain the integrity of terminally differentiated muscle by restricting transcription factor activity.
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25
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Bulterijs S, Braeckman BP. Phenotypic Screening in C. elegans as a Tool for the Discovery of New Geroprotective Drugs. Pharmaceuticals (Basel) 2020; 13:E164. [PMID: 32722365 PMCID: PMC7463874 DOI: 10.3390/ph13080164] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 07/22/2020] [Accepted: 07/22/2020] [Indexed: 01/10/2023] Open
Abstract
Population aging is one of the largest challenges of the 21st century. As more people live to advanced ages, the prevalence of age-related diseases and disabilities will increase placing an ever larger burden on our healthcare system. A potential solution to this conundrum is to develop treatments that prevent, delay or reduce the severity of age-related diseases by decreasing the rate of the aging process. This ambition has been accomplished in model organisms through dietary, genetic and pharmacological interventions. The pharmacological approaches hold the greatest opportunity for successful translation to the clinic. The discovery of such pharmacological interventions in aging requires high-throughput screening strategies. However, the majority of screens performed for geroprotective drugs in C. elegans so far are rather low throughput. Therefore, the development of high-throughput screening strategies is of utmost importance.
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Affiliation(s)
- Sven Bulterijs
- Laboratory of Aging Physiology and Molecular Evolution, Department of Biology, Ghent University, 9000 Ghent, Belgium
| | - Bart P. Braeckman
- Laboratory of Aging Physiology and Molecular Evolution, Department of Biology, Ghent University, 9000 Ghent, Belgium
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26
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McCulloch KA, Zhou K, Jin Y. Neuronal transcriptome analyses reveal novel neuropeptide modulators of excitation and inhibition imbalance in C. elegans. PLoS One 2020; 15:e0233991. [PMID: 32497060 PMCID: PMC7272019 DOI: 10.1371/journal.pone.0233991] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 05/16/2020] [Indexed: 01/06/2023] Open
Abstract
Neuropeptides are secreted molecules that have conserved roles modulating many processes, including mood, reproduction, and feeding. Dysregulation of neuropeptide signaling is also implicated in neurological disorders such as epilepsy. However, much is unknown about the mechanisms regulating specific neuropeptides to mediate behavior. Here, we report that the expression levels of dozens of neuropeptides are up-regulated in response to circuit activity imbalance in C. elegans. acr-2 encodes a homolog of human nicotinic receptors, and functions in the cholinergic motoneurons. A hyperactive mutation, acr-2(gf), causes an activity imbalance in the motor circuit. We performed cell-type specific transcriptomic analysis and identified genes differentially expressed in acr-2(gf), compared to wild type. The most over-represented class of genes are neuropeptides, with insulin-like-peptides (ILPs) the most affected. Moreover, up-regulation of neuropeptides occurs in motoneurons, as well as sensory neurons. In particular, the induced expression of the ILP ins-29 occurs in the BAG neurons, which were previously shown to function in gas-sensing. We also show that this up-regulation of ins-29 in acr-2(gf) animals is activity-dependent. Our genetic and molecular analyses support cooperative effects for ILPs and other neuropeptides in promoting motor circuit activity in the acr-2(gf) background. Together, this data reveals that a major transcriptional response to motor circuit dysregulation is in up-regulation of multiple neuropeptides, and suggests that BAG sensory neurons can respond to intrinsic activity states to feedback on the motor circuit.
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Affiliation(s)
- Katherine A. McCulloch
- Division of Biological Sciences, Section of Neurobiology, University of California San Diego, La Jolla, California, United States of America
| | - Kingston Zhou
- Division of Biological Sciences, Section of Neurobiology, University of California San Diego, La Jolla, California, United States of America
| | - Yishi Jin
- Division of Biological Sciences, Section of Neurobiology, University of California San Diego, La Jolla, California, United States of America
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27
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Fernandes Póvoa EE, Ebbing AL, Betist MC, van der Veen C, Korswagen HC. An optimized dissociation protocol for FACS-based isolation of rare cell types from Caenorhabditis elegans L1 larvae. MethodsX 2020; 7:100922. [PMID: 32509539 PMCID: PMC7265044 DOI: 10.1016/j.mex.2020.100922] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 05/09/2020] [Indexed: 10/27/2022] Open
Abstract
Single-cell isolation and transcriptomic analysis of a specific cell type or tissue offers the possibility of studying cell function and heterogeneity in time-dependent processes with remarkable resolution. The reduced tissue complexity and highly stereotyped development of Caenorhabditis elegans, combined with an extensive genetic toolbox and the ease of growing large tightly synchronized populations makes it an exceptional model organism for the application of such approaches. However, the difficulty to dissociate and isolate single cells from larval stages has been a major constraint to this kind of studies. Here, we describe an improved protocol for dissociation and preparation of single cell suspensions from developmentally synchronized populations of C. elegans L1 larvae. Our protocol has been empirically optimized to allow efficient FACS-based purification of large number of single cells from rare cell types, for subsequent extraction and sequencing of their mRNA.
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Affiliation(s)
- Euclides E. Fernandes Póvoa
- Hubrecht Institute, Royal Netherlands of Arts and Sciences and University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, Netherlands
| | - Annabel L.P. Ebbing
- Hubrecht Institute, Royal Netherlands of Arts and Sciences and University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, Netherlands
| | - Marco C. Betist
- Hubrecht Institute, Royal Netherlands of Arts and Sciences and University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, Netherlands
| | - Christa van der Veen
- Hubrecht Institute, Royal Netherlands of Arts and Sciences and University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, Netherlands
| | - Hendrik C. Korswagen
- Hubrecht Institute, Royal Netherlands of Arts and Sciences and University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, Netherlands
- Institute of Biodynamics and Biocomplexity, Developmental Biology, Department of Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, Netherlands
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28
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Germany EM, Zahayko N, Khalimonchuk O. Isolation of Specific Neuron Populations from Roundworm Caenorhabditis elegans. J Vis Exp 2019. [PMID: 31449245 DOI: 10.3791/60145] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
During the aging process, many cells accumulate high levels of damage leading to cellular dysfunction, which underlies many geriatric and pathological conditions. Post-mitotic neurons represent a major cell type affected by aging. Although multiple mammalian models of neuronal aging exist, they are challenging and expensive to establish. The roundworm Caenorhabditis elegans is a powerful model to study neuronal aging, as these animals have short lifespan, an available robust genetic toolbox, and well-cataloged nervous system. The method presented herein allows for seamless isolation of specific cells based on the expression of a transgenic green fluorescent protein (GFP). Transgenic animal lines expressing GFP under distinct, cell type-specific promoters are digested to remove the outer cuticle and gently mechanically disrupted to produce slurry containing various cell types. The cells of interest are then separated from non-target cells through fluorescence-activated cell sorting, or by anti-GFP-coupled magnetic beads. The isolated cells can then be cultured for a limited time or immediately used for cell-specific ex vivo analyses such as transcriptional analysis by real time quantitative PCR. Thus, this protocol allows for rapid and robust analysis of cell-specific responses within different neuronal populations in C. elegans.
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Affiliation(s)
| | | | - Oleh Khalimonchuk
- Department of Biochemistry, University of Nebraska; Nebraska Redox Biology Center, University of Nebraska; Nebraska Center for Integrated Biomolecular Communication, University of Nebraska; Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center;
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29
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Youssef K, Tandon A, Rezai P. Studying Parkinson’s disease using Caenorhabditis elegans models in microfluidic devices. Integr Biol (Camb) 2019; 11:186-207. [DOI: 10.1093/intbio/zyz017] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 04/30/2019] [Accepted: 05/16/2019] [Indexed: 12/21/2022]
Abstract
Abstract
Parkinson’s disease (PD) is a progressive neurological disorder associated with the loss of dopaminergic neurons (DNs) in the substantia nigra and the widespread accumulation of α-synuclein (α-syn) protein, leading to motor impairments and eventual cognitive dysfunction. In-vitro cell cultures and in-vivo animal models have provided the opportunity to investigate the PD pathological hallmarks and identify different therapeutic compounds. However, PD pathogenesis and causes are still not well understood, and effective inhibitory drugs for PD are yet to be discovered. Biologically simple but pathologically relevant disease models and advanced screening technologies are needed to reveal the mechanisms underpinning protein aggregation and PD progression. For instance, Caenorhabditis elegans (C. elegans) offers many advantages for fundamental PD neurobehavioral studies including a simple, well-mapped, and accessible neuronal system, genetic homology to humans, body transparency and amenability to genetic manipulation. Several transgenic worm strains that exhibit multiple PD-related phenotypes have been developed to perform neuronal and behavioral assays and drug screening. However, in conventional worm-based assays, the commonly used techniques are equipment-intensive, slow and low in throughput. Over the past two decades, microfluidics technology has contributed significantly to automation and control of C. elegans assays. In this review, we focus on C. elegans PD models and the recent advancements in microfluidic platforms used for manipulation, handling and neurobehavioral screening of these models. Moreover, we highlight the potential of C. elegans to elucidate the in-vivo mechanisms of neuron-to-neuron protein transfer that may underlie spreading Lewy pathology in PD, and its suitability for in-vitro studies. Given the advantages of C. elegans and microfluidics technology, their integration has the potential to facilitate the investigation of disease pathology and discovery of potential chemical leads for PD.
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Affiliation(s)
- Khaled Youssef
- Department of Mechanical Engineering, York University, Toronto, ON, Canada
| | - Anurag Tandon
- Tanz Centre for Research in Neurodegenerative Diseases, Toronto, ON, Canada
- Department of Medicine, University of Toronto, Toronto, ON, Canada
| | - Pouya Rezai
- Department of Mechanical Engineering, York University, Toronto, ON, Canada
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30
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Mathies LD, Ray S, Lopez-Alvillar K, Arbeitman MN, Davies AG, Bettinger JC. mRNA profiling reveals significant transcriptional differences between a multipotent progenitor and its differentiated sister. BMC Genomics 2019; 20:427. [PMID: 31138122 PMCID: PMC6540470 DOI: 10.1186/s12864-019-5821-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 05/21/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND The two Caenorhabditis elegans somatic gonadal precursors (SGPs) are multipotent progenitors that generate all somatic tissues of the adult reproductive system. The sister cells of the SGPs are two head mesodermal cells (hmcs); one hmc dies by programmed cell death and the other terminally differentiates. Thus, a single cell division gives rise to one multipotent progenitor and one differentiated cell with identical lineage histories. We compared the transcriptomes of SGPs and hmcs in order to learn the determinants of multipotency and differentiation in this lineage. RESULTS We generated a strain that expressed fluorescent markers specifically in SGPs (ehn-3A::tdTomato) and hmcs (bgal-1::GFP). We dissociated cells from animals after the SGP/hmc cell division, but before the SGPs had further divided, and subjected the dissociated cells to fluorescence-activated cell sorting to collect isolated SGPs and hmcs. We analyzed the transcriptomes of these cells and found that 5912 transcripts were significantly differentially expressed, with at least two-fold change in expression, between the two cell types. The hmc-biased genes were enriched with those that are characteristic of neurons. The SGP-biased genes were enriched with those indicative of cell proliferation and development. We assessed the validity of our differentially expressed genes by examining existing reporters for five of the 10 genes with the most significantly biased expression in SGPs and found that two showed expression in SGPs. For one reporter that did not show expression in SGPs, we generated a GFP knock-in using CRISPR/Cas9. This reporter, in the native genomic context, was expressed in SGPs. CONCLUSIONS We found that the transcriptional profiles of SGPs and hmcs are strikingly different. The hmc-biased genes are enriched with those that encode synaptic transmission machinery, which strongly suggests that it has neuron-like signaling properties. In contrast, the SGP-biased genes are enriched with genes that encode factors involved in transcription and translation, as would be expected from a cell preparing to undergo proliferative divisions. Mediators of multipotency are likely to be among the genes differentially expressed in SGPs.
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Affiliation(s)
- Laura D. Mathies
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, PO Box 980613, Richmond, VA 23298 USA
| | - Surjyendu Ray
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL 32306 USA
| | - Kayla Lopez-Alvillar
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, PO Box 980613, Richmond, VA 23298 USA
| | - Michelle N. Arbeitman
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL 32306 USA
| | - Andrew G. Davies
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, PO Box 980613, Richmond, VA 23298 USA
| | - Jill C. Bettinger
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, PO Box 980613, Richmond, VA 23298 USA
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31
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Turani O, Hernando G, Corradi J, Bouzat C. Activation of Caenorhabditis elegans Levamisole-Sensitive and Mammalian Nicotinic Receptors by the Antiparasitic Bephenium. Mol Pharmacol 2018; 94:1270-1279. [PMID: 30190363 DOI: 10.1124/mol.118.113357] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 08/29/2018] [Indexed: 11/22/2022] Open
Abstract
Nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels involved in neuromuscular transmission. In nematodes, muscle nAChRs are targets of antiparasitic drugs. Bephenium is an anthelmintic compound whose molecular action in the free-living nematode Caenorhabditis elegans, which is a model for anthelmintic drug discovery, is poorly known. We explored the effect of bephenium on C. elegans locomotion and applied single-channel recordings to identify its molecular target, mechanism of action, and selectivity between mammalian and C. elegans nAChRs. As in parasites, bephenium paralyzes C. elegans A mutant strain lacking the muscle levamisole-sensitive nAChR (L-AChR) shows full resistance to bephenium, indicating that this receptor is the target site. Bephenium activates L-AChR channels from larvae muscle cells in the micromolar range. Channel activity is similar to that elicited by levamisole, appearing mainly as isolated brief openings. Our analysis revealed that bephenium is an agonist of L-AChR and an open-channel blocker at higher concentrations. It also activates mammalian muscle nAChRs. Opening events are significantly briefer than those elicited by ACh and do not appear in activation episodes at a range of concentrations, indicating that it is a very weak agonist of mammalian nAChRs. Recordings in the presence of ACh showed that bephenium acts as a voltage-dependent channel blocker and a low-affinity agonist. Molecular docking into homology-modeled binding-site interfaces represent the binding mode of bephenium that explains its partial agonism. Given the great diversity of helminth nAChRs and the overlap of their pharmacological profiles, unraveling the basis of drug receptor-selectivity will be required for rational design of anthelmintic drugs.
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Affiliation(s)
- Ornella Turani
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
| | - Guillermina Hernando
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
| | - Jeremías Corradi
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
| | - Cecilia Bouzat
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
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32
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Pu M, Wang M, Wang W, Velayudhan SS, Lee SS. Unique patterns of trimethylation of histone H3 lysine 4 are prone to changes during aging in Caenorhabditis elegans somatic cells. PLoS Genet 2018; 14:e1007466. [PMID: 29912876 PMCID: PMC6023244 DOI: 10.1371/journal.pgen.1007466] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 06/28/2018] [Accepted: 06/02/2018] [Indexed: 11/18/2022] Open
Abstract
Tri-methylation on histone H3 lysine 4 (H3K4me3) is associated with active gene expression but its regulatory role in transcriptional activation is unclear. Here we used Caenorhabditis elegans to investigate the connection between H3K4me3 and gene expression regulation during aging. We uncovered around 30% of H3K4me3 enriched regions to show significant and reproducible changes with age. We further showed that these age-dynamic H3K4me3 regions largely mark gene-bodies and are acquired during adult stages. We found that these adult-specific age-dynamic H3K4me3 regions are correlated with gene expression changes with age. In contrast, H3K4me3 marking established during developmental stages remained largely stable with age, even when the H3K4me3 associated genes exhibited RNA expression changes during aging. Importantly, the genes associated with changes in H3K4me3 and RNA levels with age are enriched for functional groups commonly implicated in aging biology. Therefore, our findings suggested divergent roles of H3K4me3 in gene expression regulation during aging, with important implications on aging-dependent pathophysiologies. Histone modifications, the specific chemical modifications on histone proteins, are key for regulating the packing of DNA, and thus have important influence on diverse biological processes. An intensely studied function of histone modifications is their contribution to regulating gene expression. Recent studies in diverse model organisms demonstrated that the global alterations of particular histone modifications, for instance H3K4me3, extend the lifespan of the organism. However, the underlying molecular mechanisms remain largely unclear. In this study, we monitored whether and how the genome-wide pattern of the histone modification H3K4me3 changes during aging in the somatic cells of the model organism C. elegans. We identified interesting and non-conventional patterns of H3K4me3, which span gene-bodies and are acquired during adulthood, that are particularly prone to changes with aging. This is contrasted to the well-studied H3K4me3 patterns that span transcriptional start sites and 5’ promoter regions and are established early during development, which remain stable with age. Consistent with the close association between H3K4me3 marking and active transcription, we observed that the age-dynamic H3K4me3 markings are highly correlated with corresponding RNA expression changes. Importantly, the genes that are associated with both H3K4me3 and RNA expression changes with age are over-represented for functional groups commonly implicated in aging biology. In summary, our findings revealed a lesser known pattern of H3K4me3 modification that can have important biological roles in aging.
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Affiliation(s)
- Mintie Pu
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York City, United States of America
- * E-mail: (MP); (SSL)
| | - Minghui Wang
- Computational Biology Service Unit, Cornell University, Ithaca, New York City, United States of America
| | - Wenke Wang
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York City, United States of America
| | - Satheeja Santhi Velayudhan
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York City, United States of America
| | - Siu Sylvia Lee
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York City, United States of America
- * E-mail: (MP); (SSL)
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33
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The Microbial Zoo in the C. elegans Intestine: Bacteria, Fungi and Viruses. Viruses 2018; 10:v10020085. [PMID: 29443938 PMCID: PMC5850392 DOI: 10.3390/v10020085] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Revised: 02/08/2018] [Accepted: 02/11/2018] [Indexed: 12/13/2022] Open
Abstract
C. elegans is an invaluable model organism that has been a driving force in many fundamental biological discoveries. However, it is only in the past two decades that it has been applied to host–pathogen interaction studies. These studies have been facilitated by the discoveries of natural microbes that infect C. elegans, including bacteria, fungi and viruses. Notably, many of these microbes share a common site of infection, the C. elegans intestine. Furthermore, the recent descriptions of a natural gut microbiota in C. elegans raise the possibility that this could be a novel model system for microbiome and trans-kingdom interaction studies. Here we review studies of C. elegans host–microbe interactions with a particular focus on the intestine.
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34
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Murray JI. Systems biology of embryonic development: Prospects for a complete understanding of the Caenorhabditis elegans embryo. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2018; 7:e314. [PMID: 29369536 DOI: 10.1002/wdev.314] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 12/01/2017] [Accepted: 12/12/2017] [Indexed: 01/07/2023]
Abstract
The convergence of developmental biology and modern genomics tools brings the potential for a comprehensive understanding of developmental systems. This is especially true for the Caenorhabditis elegans embryo because its small size, invariant developmental lineage, and powerful genetic and genomic tools provide the prospect of a cellular resolution understanding of messenger RNA (mRNA) expression and regulation across the organism. We describe here how a systems biology framework might allow large-scale determination of the embryonic regulatory relationships encoded in the C. elegans genome. This framework consists of two broad steps: (a) defining the "parts list"-all genes expressed in all cells at each time during development and (b) iterative steps of computational modeling and refinement of these models by experimental perturbation. Substantial progress has been made towards defining the parts list through imaging methods such as large-scale green fluorescent protein (GFP) reporter analysis. Imaging results are now being augmented by high-resolution transcriptome methods such as single-cell RNA sequencing, and it is likely the complete expression patterns of all genes across the embryo will be known within the next few years. In contrast, the modeling and perturbation experiments performed so far have focused largely on individual cell types or genes, and improved methods will be needed to expand them to the full genome and organism. This emerging comprehensive map of embryonic expression and regulatory function will provide a powerful resource for developmental biologists, and would also allow scientists to ask questions not accessible without a comprehensive picture. This article is categorized under: Invertebrate Organogenesis > Worms Technologies > Analysis of the Transcriptome Gene Expression and Transcriptional Hierarchies > Gene Networks and Genomics.
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Affiliation(s)
- John Isaac Murray
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
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35
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Cao J, Packer JS, Ramani V, Cusanovich DA, Huynh C, Daza R, Qiu X, Lee C, Furlan SN, Steemers FJ, Adey A, Waterston RH, Trapnell C, Shendure J. Comprehensive single-cell transcriptional profiling of a multicellular organism. Science 2017; 357:661-667. [PMID: 28818938 DOI: 10.1126/science.aam8940] [Citation(s) in RCA: 822] [Impact Index Per Article: 117.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 05/12/2017] [Accepted: 07/19/2017] [Indexed: 12/14/2022]
Abstract
To resolve cellular heterogeneity, we developed a combinatorial indexing strategy to profile the transcriptomes of single cells or nuclei, termed sci-RNA-seq (single-cell combinatorial indexing RNA sequencing). We applied sci-RNA-seq to profile nearly 50,000 cells from the nematode Caenorhabditis elegans at the L2 larval stage, which provided >50-fold "shotgun" cellular coverage of its somatic cell composition. From these data, we defined consensus expression profiles for 27 cell types and recovered rare neuronal cell types corresponding to as few as one or two cells in the L2 worm. We integrated these profiles with whole-animal chromatin immunoprecipitation sequencing data to deconvolve the cell type-specific effects of transcription factors. The data generated by sci-RNA-seq constitute a powerful resource for nematode biology and foreshadow similar atlases for other organisms.
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Affiliation(s)
- Junyue Cao
- Department of Genome Sciences, University of Washington, Seattle, WA, USA.,Molecular and Cellular Biology Program, University of Washington, Seattle, WA, USA
| | - Jonathan S Packer
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Vijay Ramani
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | | | - Chau Huynh
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Riza Daza
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Xiaojie Qiu
- Department of Genome Sciences, University of Washington, Seattle, WA, USA.,Molecular and Cellular Biology Program, University of Washington, Seattle, WA, USA
| | - Choli Lee
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Scott N Furlan
- Ben Towne Center for Childhood Cancer Research, Seattle Children's Research Institute, Seattle, WA, USA.,Department of Pediatrics, University of Washington, Seattle, WA, USA.,Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | | | - Andrew Adey
- Department of Molecular & Medical Genetics, Oregon Health & Science University, Portland, OR, USA.,Knight Cardiovascular Institute, Portland, OR, USA
| | - Robert H Waterston
- Department of Genome Sciences, University of Washington, Seattle, WA, USA.
| | - Cole Trapnell
- Department of Genome Sciences, University of Washington, Seattle, WA, USA.
| | - Jay Shendure
- Department of Genome Sciences, University of Washington, Seattle, WA, USA. .,Howard Hughes Medical Institute, Seattle, WA, USA
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36
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Cao J, Packer JS, Ramani V, Cusanovich DA, Huynh C, Daza R, Qiu X, Lee C, Furlan SN, Steemers FJ, Adey A, Waterston RH, Trapnell C, Shendure J. Comprehensive single-cell transcriptional profiling of a multicellular organism. Science 2017. [DOI: 10.1126/science.aam8940 order by 10746--] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Junyue Cao
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
- Molecular and Cellular Biology Program, University of Washington, Seattle, WA, USA
| | - Jonathan S. Packer
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Vijay Ramani
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | | | - Chau Huynh
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Riza Daza
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Xiaojie Qiu
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
- Molecular and Cellular Biology Program, University of Washington, Seattle, WA, USA
| | - Choli Lee
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Scott N. Furlan
- Ben Towne Center for Childhood Cancer Research, Seattle Children’s Research Institute, Seattle, WA, USA
- Department of Pediatrics, University of Washington, Seattle, WA, USA
- Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | | | - Andrew Adey
- Department of Molecular & Medical Genetics, Oregon Health & Science University, Portland, OR, USA
- Knight Cardiovascular Institute, Portland, OR, USA
| | | | - Cole Trapnell
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Jay Shendure
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
- Howard Hughes Medical Institute, Seattle, WA, USA
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37
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Gracida X, Calarco JA. Cell type-specific transcriptome profiling in C. elegans using the Translating Ribosome Affinity Purification technique. Methods 2017. [PMID: 28648677 DOI: 10.1016/j.ymeth.2017.06.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Organs and specific cell types execute specialized functions in multicellular organisms, in large part through customized gene expression signatures. Thus, profiling the transcriptomes of specific cell and tissue types remains an important tool for understanding how cells become specialized. Methodological approaches to detect gene expression differences have utilized samples from whole animals, dissected tissues, and more recently single cells. Despite these advances, there is still a challenge and a need in most laboratories to implement less invasive yet powerful cell-type specific transcriptome profiling methods. Here, we describe the use of the Translating Ribosome Affinity Purification (TRAP) method for C. elegans to detect cell type-specific gene expression patterns at the level of translating mRNAs. In TRAP, a ribosomal protein is fused to a tag (GFP) and is expressed under cell type-specific promoters to mark genetically defined cell types in vivo. Affinity purification of lysates of animals expressing the tag enriches for ribosome-associated mRNAs of the targeted tissue. The purified mRNAs are used for making cDNA libraries subjected to high-throughput sequencing to obtain genome-wide profiles of transcripts from the targeted cell type. The ease of exposing C. elegans to diverse stimuli, coupled with available cell type specific promoters, makes TRAP a useful approach to enable the discovery of molecular components in response to external or genetic perturbations.
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Affiliation(s)
- Xicotencatl Gracida
- FAS Center for Systems Biology, Harvard University, Cambridge, MA 02138, United States; Department of Organismal and Evolutionary Biology, Harvard University, Cambridge, MA 02138, United States.
| | - John A Calarco
- FAS Center for Systems Biology, Harvard University, Cambridge, MA 02138, United States; Department of Cell and Systems Biology, University of Toronto, Toronto M5S 3G5, Canada.
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38
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Abstract
In this issue of Developmental Cell, Chaudhari and colleagues (2016) use a novel method to create an in vitro proliferative cell line from tumorous C. elegans germ cells, and in the process discover that bacterial folates act as signals for proliferation, independent of their roles as vitamins.
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Affiliation(s)
- Amy K Walker
- University of Massachusetts Medical School, 373 Plantation Street, Room 319, Worcester, MA 01605, USA.
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39
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Chaudhari SN, Mukherjee M, Vagasi AS, Bi G, Rahman MM, Nguyen CQ, Paul L, Selhub J, Kipreos ET. Bacterial Folates Provide an Exogenous Signal for C. elegans Germline Stem Cell Proliferation. Dev Cell 2017; 38:33-46. [PMID: 27404357 DOI: 10.1016/j.devcel.2016.06.013] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 05/04/2016] [Accepted: 06/09/2016] [Indexed: 11/29/2022]
Abstract
Here we describe an in vitro primary culture system for Caenorhabditis elegans germline stem cells. This culture system was used to identify a bacterial folate as a positive regulator of germ cell proliferation. Folates are a family of B-complex vitamins that function in one-carbon metabolism to allow the de novo synthesis of amino acids and nucleosides. We show that germ cell proliferation is stimulated by the folate 10-formyl-tetrahydrofolate-Glun both in vitro and in animals. Other folates that can act as vitamins to rescue folate deficiency lack this germ cell stimulatory activity. The bacterial folate precursor dihydropteroate also promotes germ cell proliferation in vitro and in vivo, despite its inability to promote one-carbon metabolism. The folate receptor homolog FOLR-1 is required for the stimulation of germ cells by 10-formyl-tetrahydrofolate-Glun and dihydropteroate. This work defines a folate and folate-related compound as exogenous signals to modulate germ cell proliferation.
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Affiliation(s)
- Snehal N Chaudhari
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
| | | | - Alexandra S Vagasi
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
| | - Gaofeng Bi
- Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA
| | - Mohammad M Rahman
- Department of Genetics, University of Georgia, Athens, GA 30602, USA
| | - Christine Q Nguyen
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
| | - Ligi Paul
- Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA
| | - Jacob Selhub
- Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA
| | - Edward T Kipreos
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA.
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40
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Ma X, Zhan G, Sleumer MC, Chen S, Liu W, Zhang MQ, Liu X. Analysis of C. elegans muscle transcriptome using trans-splicing-based RNA tagging (SRT). Nucleic Acids Res 2016; 44:e156. [PMID: 27557708 PMCID: PMC5137427 DOI: 10.1093/nar/gkw734] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 08/03/2016] [Accepted: 08/11/2016] [Indexed: 01/02/2023] Open
Abstract
Current approaches to profiling tissue-specific gene expression in C. elegans require delicate manipulation and are difficult under certain conditions, e.g. from dauer or aging worms. We have developed an easy and robust method for tissue-specific RNA-seq by taking advantage of the endogenous trans-splicing process. In this method, transgenic worms are generated in which a spliced leader (SL) RNA gene is fused with a sequence tag and driven by a tissue-specific promoter. Only in the tissue of interest, the tagged SL RNA gene is transcribed and then trans-spliced onto mRNAs. The tag allows enrichment and sequencing of mRNAs from that tissue only. As a proof of principle, we profiled the muscle transcriptome, which showed high coverage and efficient enrichment of muscle specific genes, with low background noise. To demonstrate the robustness of our method, we profiled muscle gene expression in dauer larvae and aging worms, revealing gene expression changes consistent with the physiology of these stages. The resulting muscle transcriptome also revealed 461 novel RNA transcripts, likely muscle-expressed long non-coding RNAs. In summary, the splicing-based RNA tagging (SRT) method provides a convenient and robust tool to profile trans-spliced genes and identify novel transcripts in a tissue-specific manner, with a low false positive rate.
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Affiliation(s)
- Xiaopeng Ma
- MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.,PTN (Peking University-Tsinghua University-National Institute of Biological Sciences) Joint Graduate Program, Beijing 100084, China
| | - Ge Zhan
- MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Monica C Sleumer
- MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Siyu Chen
- MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Weihong Liu
- MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Michael Q Zhang
- MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.,Departmental of Biological Sciences, Center for Systems Biology, The University of Texas at Dallas, TX 75080, USA.,Division of Bioinformatics, TNLIST, School of Information Sciences, Tsinghua University, Beijing 100084, China
| | - Xiao Liu
- MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
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41
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Imanikia S, Galea F, Nagy E, Phillips DH, Stürzenbaum SR, Arlt VM. The application of the comet assay to assess the genotoxicity of environmental pollutants in the nematode Caenorhabditis elegans. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2016; 45:356-61. [PMID: 27389785 PMCID: PMC4962771 DOI: 10.1016/j.etap.2016.06.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 05/13/2016] [Accepted: 06/18/2016] [Indexed: 05/04/2023]
Abstract
This study aimed to establish a protocol for cell dissociation from the nematode Caenorhabditis elegans (C. elegans) to assess the genotoxicity of the environmental pollutant benzo[a]pyrene (BaP) using the alkaline version of the single cell electrophoresis assay (comet assay). BaP genotoxicity was assessed in C. elegans (wild-type [WT]; N2, Bristol) after 48h exposure (0-40μM). Induction of comets by BaP was concentration-dependent up to 20μM; comet% tail DNA was ∼30% at 20μM BaP and ∼10% in controls. Similarly, BaP-induced DNA damage was evaluated in C. elegans mutant strains deficient in DNA repair. In xpa-1 and apn-1 mutants BaP-induced comet formation was diminished to WT background levels suggesting that the damage formed by BaP that is detected in the comet assay is not recognised in cells deficient in nucleotide and base excision repair, respectively. In summary, our study provides a protocol to evaluate DNA damage of environmental pollutants in whole nematodes using the comet assay.
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Affiliation(s)
- Soudabeh Imanikia
- Analytical and Environmental Sciences Division, MRC-PHE Centre for Environment and Health, King's College London, London, United Kingdom
| | - Francesca Galea
- Analytical and Environmental Sciences Division, MRC-PHE Centre for Environment and Health, King's College London, London, United Kingdom
| | - Eszter Nagy
- Analytical and Environmental Sciences Division, MRC-PHE Centre for Environment and Health, King's College London, London, United Kingdom
| | - David H Phillips
- Analytical and Environmental Sciences Division, MRC-PHE Centre for Environment and Health, King's College London, London, United Kingdom; NIHR Health Protection Research Unit in Health Impact of Environmental Hazards at King's College London in partnership with Public Health England, London, United Kingdom
| | - Stephen R Stürzenbaum
- Analytical and Environmental Sciences Division, MRC-PHE Centre for Environment and Health, King's College London, London, United Kingdom
| | - Volker M Arlt
- Analytical and Environmental Sciences Division, MRC-PHE Centre for Environment and Health, King's College London, London, United Kingdom; NIHR Health Protection Research Unit in Health Impact of Environmental Hazards at King's College London in partnership with Public Health England, London, United Kingdom.
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42
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Zheng J, Wang M, Wei W, Keller JN, Adhikari B, King JF, King ML, Peng N, Laine RA. Dietary Plant Lectins Appear to Be Transported from the Gut to Gain Access to and Alter Dopaminergic Neurons of Caenorhabditis elegans, a Potential Etiology of Parkinson's Disease. Front Nutr 2016; 3:7. [PMID: 27014695 PMCID: PMC4780318 DOI: 10.3389/fnut.2016.00007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Accepted: 02/15/2016] [Indexed: 11/13/2022] Open
Abstract
Lectins from dietary plants have been shown to enhance drug absorption in the gastrointestinal tract of rats, be transported trans-synaptically as shown by tracing of axonal and dendritic paths, and enhance gene delivery. Other carbohydrate-binding protein toxins are known to traverse the gut intact in dogs. Post-feeding rhodamine- or TRITC-tagged dietary lectins, the lectins were tracked from gut to dopaminergic neurons (DAergic-N) in transgenic Caenorhabditis elegans (C. elegans) [egIs1(Pdat-1:GFP)] where the mutant has the green fluorescent protein (GFP) gene fused to a dopamine transport protein gene labeling DAergic-N. The lectins were supplemented along with the food organism Escherichia coli (OP50). Among nine tested rhodamine/TRITC-tagged lectins, four, including Phaseolus vulgaris erythroagglutinin (PHA-E), Bandeiraea simplicifolia (BS-I), Dolichos biflorus agglutinin (DBA), and Arachis hypogaea agglutinin (PNA), appeared to be transported from gut to the GFP-DAergic-N. Griffonia Simplicifolia and PHA-E, reduced the number of GFP-DAergic-N, suggesting a toxic activity. PHA-E, BS-I, Pisum sativum (PSA), and Triticum vulgaris agglutinin (Succinylated) reduced fluorescent intensity of GFP-DAergic-N. PHA-E, PSA, Concanavalin A, and Triticum vulgaris agglutinin decreased the size of GFP-DAergic-N, while BS-I increased neuron size. These observations suggest that dietary plant lectins are transported to and affect DAergic-N in C. elegans, which support Braak and Hawkes' hypothesis, suggesting one alternate potential dietary etiology of Parkinson's disease (PD). A recent Danish study showed that vagotomy resulted in 40% lower incidence of PD over 20 years. Differences in inherited sugar structures of gut and neuronal cell surfaces may make some individuals more susceptible in this conceptual disease etiology model.
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Affiliation(s)
- Jolene Zheng
- School of Nutrition and Food Sciences, Louisiana State University, Baton Rouge, LA, USA
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Mingming Wang
- School of Nutrition and Food Sciences, Louisiana State University, Baton Rouge, LA, USA
| | - Wenqian Wei
- Department of Veterinary Science, College of Agriculture, Louisiana State University, Baton Rouge, LA, USA
- School of Life Sciences, Fudan University, Shanghai, China
| | - Jeffrey N. Keller
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Binita Adhikari
- Nicholls State University, Thibodaux, LA, USA
- Louisiana Biomedical Research Network (LBRN) Summer Research Program (2010), Baton Rouge, LA, USA
| | - Jason F. King
- Department of Biological Sciences, Louisiana State University and A&M College, Baton Rouge, LA, USA
- Department of Chemistry, Louisiana State University and A&M College, Baton Rouge, LA, USA
| | - Michael L. King
- Department of Biological Sciences, Louisiana State University and A&M College, Baton Rouge, LA, USA
- Department of Chemistry, Louisiana State University and A&M College, Baton Rouge, LA, USA
| | - Nan Peng
- School of Life Sciences, Fudan University, Shanghai, China
| | - Roger A. Laine
- Department of Biological Sciences, Louisiana State University and A&M College, Baton Rouge, LA, USA
- Department of Chemistry, Louisiana State University and A&M College, Baton Rouge, LA, USA
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43
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Burdick J, Walton T, Preston E, Zacharias A, Raj A, Murray JI. Overlapping cell population expression profiling and regulatory inference in C. elegans. BMC Genomics 2016; 17:159. [PMID: 26926147 PMCID: PMC4772325 DOI: 10.1186/s12864-016-2482-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 02/17/2016] [Indexed: 12/30/2022] Open
Abstract
Background Understanding gene expression across the diverse metazoan cell types during development is critical to understanding their function and regulation. However, most cell types have not been assayed for expression genome-wide. Results We applied a novel approach we term “Profiling of Overlapping Populations of cells (POP-Seq)” to assay differential expression across all embryonic cells in the nematode Caenorhabditis elegans. In this approach, we use RNA-seq to define the transcriptome of diverse partially overlapping FACS-sorted cell populations. This identified thousands of transcripts differentially expressed across embryonic cells. Hierarchical clustering analysis identified over 100 sets of coexpressed genes corresponding to distinct patterns of cell type specific expression. We identified thousands of candidate regulators of these clusters based on enrichment of transcription factor motifs and experimentally determined binding sites. Conclusions Our analysis provides new insight into embryonic gene regulation, and provides a resource for improving our knowledge of tissue-specific expression and its regulation throughout C. elegans development. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2482-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Joshua Burdick
- Department of Genetics, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
| | - Travis Walton
- Department of Genetics, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
| | - Elicia Preston
- Department of Genetics, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
| | - Amanda Zacharias
- Department of Genetics, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
| | - Arjun Raj
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
| | - John Isaac Murray
- Department of Genetics, University of Pennsylvania, Philadelphia, Pennsylvania, USA. .,Department of Genetics, Perelman School of Medicine, University of Pennsylvania, 437A Clinical Research Building, 415 Curie Boulevard, Philadelphia, PA, 19104-6145, USA.
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44
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Kaletsky R, Lakhina V, Arey R, Williams A, Landis J, Ashraf J, Murphy CT. The C. elegans adult neuronal IIS/FOXO transcriptome reveals adult phenotype regulators. Nature 2015; 529:92-6. [PMID: 26675724 PMCID: PMC4708089 DOI: 10.1038/nature16483] [Citation(s) in RCA: 158] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 11/25/2015] [Indexed: 12/30/2022]
Abstract
Insulin/IGF-1 signaling (IIS) is a critical regulator of an organism’s most important biological decisions, from growth, development, and metabolism to reproduction and longevity. It primarily does so through the activity of the DAF-16/FOXO transcription factor, whose global targets were identified in C. elegans using whole-worm transcriptional analyses more than a decade ago1. IIS and FOXO also regulate important neuronal and adult behavioral phenotypes, such as the maintenance of memory2 and axon regeneration3 with age, in both mammals4 and C. elegans, but the neuron-specific IIS/FOXO targets that regulate these functions are still unknown. By isolating adult C. elegans neurons for transcriptional profiling, we identified both the wild-type and IIS/FOXO adult neuronal transcriptomes for the first time. IIS/FOXO neuron-specific targets are distinct from canonical IIS/FOXO-regulated longevity and metabolism targets, and are required for IIS/daf-2 mutants’ extended memory. We also discovered that the activity of the forkhead transcription factor FKH-9 in neurons is required for daf-2’s ability to regenerate axons with age, and its activity in non-neuronal tissues is required for daf-2’s long lifespan. Together, neuron-specific and canonical IIS/FOXO-regulated targets enable the coordinated extension of neuronal activities, metabolism, and longevity under low insulin-signaling conditions.
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Affiliation(s)
- Rachel Kaletsky
- Department of Molecular Biology &LSI Genomics, Princeton University, Princeton, New Jersey 08544, USA
| | - Vanisha Lakhina
- Department of Molecular Biology &LSI Genomics, Princeton University, Princeton, New Jersey 08544, USA
| | - Rachel Arey
- Department of Molecular Biology &LSI Genomics, Princeton University, Princeton, New Jersey 08544, USA
| | - April Williams
- Department of Molecular Biology &LSI Genomics, Princeton University, Princeton, New Jersey 08544, USA
| | - Jessica Landis
- Department of Molecular Biology &LSI Genomics, Princeton University, Princeton, New Jersey 08544, USA
| | - Jasmine Ashraf
- Department of Molecular Biology &LSI Genomics, Princeton University, Princeton, New Jersey 08544, USA
| | - Coleen T Murphy
- Department of Molecular Biology &LSI Genomics, Princeton University, Princeton, New Jersey 08544, USA
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Kroetz MB, Zarkower D. Cell-Specific mRNA Profiling of the Caenorhabditis elegans Somatic Gonadal Precursor Cells Identifies Suites of Sex-Biased and Gonad-Enriched Transcripts. G3 (BETHESDA, MD.) 2015; 5:2831-41. [PMID: 26497144 PMCID: PMC4683654 DOI: 10.1534/g3.115.022517] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 10/16/2015] [Indexed: 02/07/2023]
Abstract
The Caenorhabditis elegans somatic gonad differs greatly between the two sexes in its pattern of cell divisions, migration, and differentiation. Despite decades of study, the genetic pathways directing early gonadal development and establishing sexual dimorphism in the gonad remain largely unknown. To help define the genetic networks that regulate gonadal development, we employed cell-specific RNA-seq. We identified transcripts present in the somatic gonadal precursor cells and their daughter cells of each sex at the onset of sexual differentiation. We identified several hundred gonad-enriched transcripts, including the majority of known regulators of early gonadal development, and transgenic reporter analysis confirmed the effectiveness of this approach. Before the division of the somatic gonad precursors, few sex-biased gonadal transcripts were detectable; less than 6 hr later, after their division, we identified more than 250 sex-biased transcripts, of which about a third were enriched in the somatic gonad compared to the whole animal. This indicates that a robust sex-biased developmental program, some of it gonad-specific, initiates in the somatic gonadal precursor cells around the time of their first division. About 10% of male-biased transcripts had orthologs with male-biased expression in the early mouse gonad, suggesting possible conservation of gonad sex differentiation. Cell-specific analysis also identified approximately 70 previously unannotated mRNA isoforms that are enriched in the somatic gonad. Our data illustrate the power of cell-specific transcriptome analysis and suggest that early sex differentiation in the gonad is controlled by a relatively small suite of differentially expressed genes, even after dimorphism has become apparent.
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Affiliation(s)
- Mary B Kroetz
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, Minnesota 55455
| | - David Zarkower
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, Minnesota 55455 Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota 55455
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Drebrin-like protein DBN-1 is a sarcomere component that stabilizes actin filaments during muscle contraction. Nat Commun 2015; 6:7523. [PMID: 26146072 DOI: 10.1038/ncomms8523] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 05/16/2015] [Indexed: 01/22/2023] Open
Abstract
Actin filament organization and stability in the sarcomeres of muscle cells are critical for force generation. Here we identify and functionally characterize a Caenorhabditis elegans drebrin-like protein DBN-1 as a novel constituent of the muscle contraction machinery. In vitro, DBN-1 exhibits actin filament binding and bundling activity. In vivo, DBN-1 is expressed in body wall muscles of C. elegans. During the muscle contraction cycle, DBN-1 alternates location between myosin- and actin-rich regions of the sarcomere. In contracted muscle, DBN-1 is accumulated at I-bands where it likely regulates proper spacing of α-actinin and tropomyosin and protects actin filaments from the interaction with ADF/cofilin. DBN-1 loss of function results in the partial depolymerization of F-actin during muscle contraction. Taken together, our data show that DBN-1 organizes the muscle contractile apparatus maintaining the spatial relationship between actin-binding proteins such as α-actinin, tropomyosin and ADF/cofilin and possibly strengthening actin filaments by bundling.
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Abstract
A little over 50 years ago, Sydney Brenner had the foresight to develop the nematode (round worm) Caenorhabditis elegans as a genetic model for understanding questions of developmental biology and neurobiology. Over time, research on C. elegans has expanded to explore a wealth of diverse areas in modern biology including studies of the basic functions and interactions of eukaryotic cells, host-parasite interactions, and evolution. C. elegans has also become an important organism in which to study processes that go awry in human diseases. This primer introduces the organism and the many features that make it an outstanding experimental system, including its small size, rapid life cycle, transparency, and well-annotated genome. We survey the basic anatomical features, common technical approaches, and important discoveries in C. elegans research. Key to studying C. elegans has been the ability to address biological problems genetically, using both forward and reverse genetics, both at the level of the entire organism and at the level of the single, identified cell. These possibilities make C. elegans useful not only in research laboratories, but also in the classroom where it can be used to excite students who actually can see what is happening inside live cells and tissues.
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Affiliation(s)
- Ann K Corsi
- Biology Department, The Catholic University of America, Washington, DC 20064
| | - Bruce Wightman
- Biology Department, Muhlenberg College, Allentown, Pennsylvania 18104
| | - Martin Chalfie
- Department of Biological Sciences, Columbia University, New York, New York 10027
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Grants JM, Goh GYS, Taubert S. The Mediator complex of Caenorhabditis elegans: insights into the developmental and physiological roles of a conserved transcriptional coregulator. Nucleic Acids Res 2015; 43:2442-53. [PMID: 25634893 PMCID: PMC4344494 DOI: 10.1093/nar/gkv037] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The Mediator multiprotein complex (‘Mediator’) is an important transcriptional coregulator that is evolutionarily conserved throughout eukaryotes. Although some Mediator subunits are essential for the transcription of all protein-coding genes, others influence the expression of only subsets of genes and participate selectively in cellular signaling pathways. Here, we review the current knowledge of Mediator subunit function in the nematode Caenorhabditis elegans, a metazoan in which established and emerging genetic technologies facilitate the study of developmental and physiological regulation in vivo. In this nematode, unbiased genetic screens have revealed critical roles for Mediator components in core developmental pathways such as epidermal growth factor (EGF) and Wnt/β-catenin signaling. More recently, important roles for C. elegans Mediator subunits have emerged in the regulation of lipid metabolism and of systemic stress responses, engaging conserved transcription factors such as nuclear hormone receptors (NHRs). We emphasize instances where similar functions for individual Mediator subunits exist in mammals, highlighting parallels between Mediator subunit action in nematode development and in human cancer biology. We also discuss a parallel between the association of the Mediator subunit MED12 with several human disorders and the role of its C. elegans ortholog mdt-12 as a regulatory hub that interacts with numerous signaling pathways.
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Affiliation(s)
- Jennifer M Grants
- Department of Medical Genetics, University of British Columbia, Vancouver, BC V5Z 4H4, Canada Centre for Molecular Medicine and Therapeutics, Child & Family Research Institute, University of British Columbia, Vancouver, BC V5Z 4H4, Canada
| | - Grace Y S Goh
- Centre for Molecular Medicine and Therapeutics, Child & Family Research Institute, University of British Columbia, Vancouver, BC V5Z 4H4, Canada Graduate Program in Cell and Developmental Biology, University of British Columbia, Vancouver, BC V5Z 4H4, Canada
| | - Stefan Taubert
- Department of Medical Genetics, University of British Columbia, Vancouver, BC V5Z 4H4, Canada Centre for Molecular Medicine and Therapeutics, Child & Family Research Institute, University of British Columbia, Vancouver, BC V5Z 4H4, Canada Graduate Program in Cell and Developmental Biology, University of British Columbia, Vancouver, BC V5Z 4H4, Canada
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Geary TG, Sakanari JA, Caffrey CR. Anthelmintic drug discovery: into the future. J Parasitol 2015; 101:125-33. [PMID: 25584662 DOI: 10.1645/14-703.1] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The last half-century has provided all of the (few) drugs currently used to treat human helminthiases. Concern regarding the long-term utility of these drugs, given how readily resistance evolves in the veterinary-agricultural sector, spurs the discovery of new chemical entities. We review the approaches and technologies in use to identify anthelmintics and discuss a number of drug discovery paradigms that may prove pivotal to the next half-century of anthelmintic development.
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Affiliation(s)
- Timothy G Geary
- Institute of Parasitology, McGill University, 21,111 Lakeshore Road, Ste. Anne de Bellevue, Quebec, Canada H9X 3V9
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Snodgrass CJ, Burnham-Marusich AR, Meteer JC, Berninsone PM. Conserved ion and amino acid transporters identified as phosphorylcholine-modified N-glycoproteins by metabolic labeling with propargylcholine in Caenorhabditis elegans cells. Glycobiology 2014; 25:403-11. [PMID: 25387872 DOI: 10.1093/glycob/cwu122] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Phosphorylcholine (PC) modification of proteins by pathogens has been implicated in mediating host-pathogen interactions. Parasitic nematodes synthesize PC-modified biomolecules that can modulate the host's antibody and cytokine production to favor nematode survival, contributing to long-term infections. Only two nematode PC-modified proteins (PC-proteins) have been unequivocally identified, yet discovering the protein targets of PC modification will be paramount to understanding the role(s) that this epitope plays in nematode biology. A major hurdle in the field has been the lack of techniques for selective purification of PC-proteins. The nonparasitic nematode Caenorhabditis elegans expresses PC-modified N-linked glycans, offering an attractive model to study the biology of PC-modification. We developed a robust method to identify PC-proteins by metabolic labeling of primary embryonic C. elegans cells with propargylcholine, an alkyne-modified choline analog. Cu(I)-catalyzed cycloaddition with biotin-azide enables streptavidin purification and subsequent high-throughput LC-MS identification of propargyl-labeled proteins. All proteins identified using stringent criteria are known or predicted to be membrane or secreted proteins, consistent with the model of a Golgi-resident, putative PC-transferase. Of the 55 PC-N-glycosylation sites reported, 33 have been previously observed as N-glycosylation sites in high-throughput screens of C. elegans. Several identified PC-proteins are nematode-specific proteins, but 10 of the PC-proteins are widely conserved ion transporters and amino acid transporters, while eight are conserved proteins involved in synaptic function. This finding suggests a functional role for PC-modification beyond immunomodulation. The approach presented in this study provides a method to identify PC-proteins in C. elegans and related nematodes.
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Affiliation(s)
| | | | - John C Meteer
- Department of Biology, University of Nevada, Reno, NV 89557, USA
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