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Funk OH, Levy DL, Fay DS. Epidermal cell fusion promotes the transition from an embryonic to a larval transcriptome in C. elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.22.595354. [PMID: 38826300 PMCID: PMC11142173 DOI: 10.1101/2024.05.22.595354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Cell fusion is a fundamental process in the development of multicellular organisms, yet its impact on gene regulation, particularly during crucial developmental stages, remains poorly understood. The Caenorhabditis elegans epidermis comprises 8-10 syncytial cells, with the largest integrating 139 individual nuclei through cell-cell fusion governed by the fusogenic protein EFF-1. To explore the effects of cell fusion on developmental progression and associated gene expression changes, we conducted transcriptomic analyses of eff-1 fusion-deficient mutants. Our RNAseq findings showed widespread transcriptomic changes that were enriched for epidermal genes and key molecular pathways involved in epidermal function during larval development. Subsequent single-molecule fluorescence in situ hybridization validated the altered expression of mRNA transcripts, confirming quantifiable changes in gene expression in the absence of embryonic epidermal fusion. These results underscore the significance of cell-cell fusion in shaping transcriptional programs during development and raise questions regarding the precise identities and specialized functions of different subclasses of nuclei within developing syncytial cells and tissues.
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2
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Sabharwal V, Boyanapalli SPP, Shee A, Nonet ML, Nandi A, Chaudhuri D, Koushika SP. F-box protein FBXB-65 regulates anterograde transport of the kinesin-3 motor UNC-104 through a PTM near its cargo-binding PH domain. J Cell Sci 2024; 137:jcs261553. [PMID: 38477340 PMCID: PMC11058344 DOI: 10.1242/jcs.261553] [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: 08/15/2023] [Accepted: 03/06/2024] [Indexed: 03/14/2024] Open
Abstract
Axonal transport in neurons is essential for cargo movement between the cell body and synapses. Caenorhabditis elegans UNC-104 and its homolog KIF1A are kinesin-3 motors that anterogradely transport precursors of synaptic vesicles (pre-SVs) and are degraded at synapses. However, in C. elegans, touch neuron-specific knockdown of the E1 ubiquitin-activating enzyme, uba-1, leads to UNC-104 accumulation at neuronal ends and synapses. Here, we performed an RNAi screen and identified that depletion of fbxb-65, which encodes an F-box protein, leads to UNC-104 accumulation at neuronal distal ends, and alters UNC-104 net anterograde movement and levels of UNC-104 on cargo without changing synaptic UNC-104 levels. Split fluorescence reconstitution showed that UNC-104 and FBXB-65 interact throughout the neuron. Our theoretical model suggests that UNC-104 might exhibit cooperative cargo binding that is regulated by FBXB-65. FBXB-65 regulates an unidentified post-translational modification (PTM) of UNC-104 in a region beside the cargo-binding PH domain. Both fbxb-65 and UNC-104, independently of FBXB-65, regulate axonal pre-SV distribution, transport of pre-SVs at branch points and organismal lifespan. FBXB-65 regulates a PTM of UNC-104 and the number of motors on the cargo surface, which can fine-tune cargo transport to the synapse.
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Affiliation(s)
- Vidur Sabharwal
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India
| | | | - Amir Shee
- Institute of Physics, Sachivalaya Marg, Bhubaneswar 751005, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
- Northwestern Institute on Complex Systems and ESAM, Northwestern University, Evanston, IL 60208, USA
| | - Michael L. Nonet
- Department of Neuroscience, Washington University School of Medicine, St Louis, MO 63110, USA
| | - Amitabha Nandi
- Department of Physics, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Debasish Chaudhuri
- Institute of Physics, Sachivalaya Marg, Bhubaneswar 751005, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - Sandhya P. Koushika
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India
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3
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Pohl F, Germann AL, Mao J, Hou S, Bakare B, Kong Thoo Lin P, Yates K, Nonet ML, Akk G, Kornfeld K, Held JM. UNC-49 is a redox-sensitive GABA A receptor that regulates the mitochondrial unfolded protein response cell nonautonomously. SCIENCE ADVANCES 2023; 9:eadh2584. [PMID: 37910615 PMCID: PMC10619936 DOI: 10.1126/sciadv.adh2584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 09/29/2023] [Indexed: 11/03/2023]
Abstract
The γ-aminobutyric acid-mediated (GABAergic) system participates in many aspects of organismal physiology and disease, including proteostasis, neuronal dysfunction, and life-span extension. Many of these phenotypes are also regulated by reactive oxygen species (ROS), but the redox mechanisms linking the GABAergic system to these phenotypes are not well defined. Here, we report that GABAergic redox signaling cell nonautonomously activates many stress response pathways in Caenorhabditis elegans and enhances vulnerability to proteostasis disease in the absence of oxidative stress. Cell nonautonomous redox activation of the mitochondrial unfolded protein response (mitoUPR) proteostasis network requires UNC-49, a GABAA receptor that we show is activated by hydrogen peroxide. MitoUPR induction by a spinocerebellar ataxia type 3 (SCA3) C. elegans neurodegenerative disease model was similarly dependent on UNC-49 in C. elegans. These results demonstrate a multi-tissue paradigm for redox signaling in the GABAergic system that is transduced via a GABAA receptor to function in cell nonautonomous regulation of health, proteostasis, and disease.
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Affiliation(s)
- Franziska Pohl
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Allison L. Germann
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Jack Mao
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Sydney Hou
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Bayode Bakare
- School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, UK
| | - Paul Kong Thoo Lin
- School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, UK
| | - Kyari Yates
- School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, UK
| | - Michael L. Nonet
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, USA
| | - Gustav Akk
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA
- Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA
| | - Kerry Kornfeld
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Jason M. Held
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA
- Siteman Cancer Center, Washington University School of Medicine, St. Louis, MO, USA
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4
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Brocal-Ruiz R, Esteve-Serrano A, Mora-Martínez C, Franco-Rivadeneira ML, Swoboda P, Tena JJ, Vilar M, Flames N. Forkhead transcription factor FKH-8 cooperates with RFX in the direct regulation of sensory cilia in Caenorhabditis elegans. eLife 2023; 12:e89702. [PMID: 37449480 PMCID: PMC10393296 DOI: 10.7554/elife.89702] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 07/07/2023] [Indexed: 07/18/2023] Open
Abstract
Cilia, either motile or non-motile (a.k.a primary or sensory), are complex evolutionarily conserved eukaryotic structures composed of hundreds of proteins required for their assembly, structure and function that are collectively known as the ciliome. Ciliome gene mutations underlie a group of pleiotropic genetic diseases known as ciliopathies. Proper cilium function requires the tight coregulation of ciliome gene transcription, which is only fragmentarily understood. RFX transcription factors (TF) have an evolutionarily conserved role in the direct activation of ciliome genes both in motile and non-motile cilia cell-types. In vertebrates, FoxJ1 and FoxN4 Forkhead (FKH) TFs work with RFX in the direct activation of ciliome genes, exclusively in motile cilia cell-types. No additional TFs have been described to act together with RFX in primary cilia cell-types in any organism. Here we describe FKH-8, a FKH TF, as a direct regulator of the sensory ciliome genes in Caenorhabditis elegans. FKH-8 is expressed in all ciliated neurons in C. elegans, binds the regulatory regions of ciliome genes, regulates ciliome gene expression, cilium morphology and a wide range of behaviors mediated by sensory ciliated neurons. FKH-8 and DAF-19 (C. elegans RFX) physically interact and synergistically regulate ciliome gene expression. C. elegans FKH-8 function can be replaced by mouse FOXJ1 and FOXN4 but not by other members of other mouse FKH subfamilies. In conclusion, RFX and FKH TF families act jointly as direct regulators of ciliome genes also in sensory ciliated cell types suggesting that this regulatory logic could be an ancient trait predating functional cilia sub-specialization.
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Affiliation(s)
- Rebeca Brocal-Ruiz
- Developmental Neurobiology Unit, Instituto de Biomedicina de Valencia IBV-CSICValenciaSpain
| | - Ainara Esteve-Serrano
- Developmental Neurobiology Unit, Instituto de Biomedicina de Valencia IBV-CSICValenciaSpain
| | - Carlos Mora-Martínez
- Developmental Neurobiology Unit, Instituto de Biomedicina de Valencia IBV-CSICValenciaSpain
| | | | - Peter Swoboda
- Department of Biosciences and Nutrition. Karolinska Institute. Campus FlemingsbergStockholmSweden
| | - Juan J Tena
- Centro Andaluz de Biología del Desarrollo (CABD), Consejo Superior de Investigaciones Científicas/Universidad Pablo de OlavideSevilleSpain
| | - Marçal Vilar
- Molecular Basis of Neurodegeneration Unit, Instituto de Biomedicina de Valencia IBV-CSICValenciaSpain
| | - Nuria Flames
- Developmental Neurobiology Unit, Instituto de Biomedicina de Valencia IBV-CSICValenciaSpain
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Cerón J. Caenorhabditis elegans for research on cancer hallmarks. Dis Model Mech 2023; 16:dmm050079. [PMID: 37278614 PMCID: PMC10259857 DOI: 10.1242/dmm.050079] [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: 06/07/2023] Open
Abstract
After decades of research, our knowledge of the complexity of cancer mechanisms, elegantly summarized as 'hallmarks of cancer', is expanding, as are the therapeutic opportunities that this knowledge brings. However, cancer still needs intense research to diminish its tremendous impact. In this context, the use of simple model organisms such as Caenorhabditis elegans, in which the genetics of the apoptotic pathway was discovered, can facilitate the investigation of several cancer hallmarks. Amenable for genetic and drug screens, convenient for fast and efficient genome editing, and aligned with the 3Rs ('Replacement, Reduction and Refinement') principles for ethical animal research, C. elegans plays a significant role in unravelling the intricate network of cancer mechanisms and presents a promising option in clinical diagnosis and drug discovery.
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Affiliation(s)
- Julián Cerón
- Modeling Human Diseases in C. elegans Group – Genes, Disease and Therapy Program, Bellvitge Biomedical Research Institute – IDIBELL, 08908 L'Hospitalet de Llobregat, Barcelona, Spain
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Paschinger K, Wöls F, Yan S, Jin C, Vanbeselaere J, Dutkiewicz Z, Arcalis E, Malzl D, Wilson IBH. N-glycan antennal modifications are altered in Caenorhabditis elegans lacking the HEX-4 N-acetylgalactosamine-specific hexosaminidase. J Biol Chem 2023; 299:103053. [PMID: 36813232 PMCID: PMC10060765 DOI: 10.1016/j.jbc.2023.103053] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 02/16/2023] [Accepted: 02/17/2023] [Indexed: 02/24/2023] Open
Abstract
Simple organisms are often considered to have simple glycomes, but plentiful paucimannosidic and oligomannosidic glycans overshadow the less abundant N-glycans with highly variable core and antennal modifications; Caenorhabditis elegans is no exception. By use of optimized fractionation and assessing wildtype in comparison to mutant strains lacking either the HEX-4 or HEX-5 β-N-acetylgalactosaminidases, we conclude that the model nematode has a total N-glycomic potential of 300 verified isomers. Three pools of glycans were analyzed for each strain: either PNGase F released and eluted from a reversed-phase C18 resin with either water or 15% methanol or PNGase Ar released. While the water-eluted fractions were dominated by typical paucimannosidic and oligomannosidic glycans and the PNGase Ar-released pools by glycans with various core modifications, the methanol-eluted fractions contained a huge range of phosphorylcholine-modified structures with up to three antennae, sometimes with four N-acetylhexosamine residues in series. There were no major differences between the C. elegans wildtype and hex-5 mutant strains, but the hex-4 mutant strains displayed altered sets of methanol-eluted and PNGase Ar-released pools. In keeping with the specificity of HEX-4, there were more glycans capped with N-acetylgalactosamine in the hex-4 mutants, as compared with isomeric chito-oligomer motifs in the wildtype. Considering that fluorescence microscopy showed that a HEX-4::enhanced GFP fusion protein colocalizes with a Golgi tracker, we conclude that HEX-4 plays a significant role in late-stage Golgi processing of N-glycans in C. elegans. Furthermore, finding more "parasite-like" structures in the model worm may facilitate discovery of glycan-processing enzymes occurring in other nematodes.
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Affiliation(s)
| | - Florian Wöls
- Department für Chemie, Universität für Bodenkultur, Wien, Austria
| | - Shi Yan
- Department für Chemie, Universität für Bodenkultur, Wien, Austria; Institut für Parasitologie, Veterinärmedizinische Universität, Wien, Austria
| | - Chunsheng Jin
- Institutionen för Biomedicin, Göteborgs universitet, Göteborg, Sweden
| | | | | | - Elsa Arcalis
- Department für angewandte Genetik und Zellbiologie, Universität für Bodenkultur, Wien, Austria
| | - Daniel Malzl
- Department für Chemie, Universität für Bodenkultur, Wien, Austria
| | - Iain B H Wilson
- Department für Chemie, Universität für Bodenkultur, Wien, Austria.
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7
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Wilson IBH, Yan S, Jin C, Dutkiewicz Z, Rendić D, Palmberger D, Schnabel R, Paschinger K. Increasing Complexity of the N-Glycome During Caenorhabditis Development. Mol Cell Proteomics 2023; 22:100505. [PMID: 36717059 PMCID: PMC7614267 DOI: 10.1016/j.mcpro.2023.100505] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 01/06/2023] [Accepted: 01/24/2023] [Indexed: 01/30/2023] Open
Abstract
Caenorhabditis elegans is a frequently employed genetic model organism and has been the object of a wide range of developmental, genetic, proteomic, and glycomic studies. Here, using an off-line MALDI-TOF-MS approach, we have analyzed the N-glycans of mixed embryos and liquid- or plate-grown L4 larvae. Of the over 200 different annotatable N-glycan structures, variations between the stages as well as the mode of cultivation were observed. While the embryonal N-glycome appears less complicated overall, the liquid- and plate-grown larvae differ especially in terms of methylation of bisecting fucose, α-galactosylation of mannose, and di-β-galactosylation of core α1,6-fucose. Furthermore, we analyzed the O-glycans by LC-electrospray ionization-MS following β-elimination; especially the embryonal O-glycomes included a set of phosphorylcholine-modified structures, previously not shown to exist in nematodes. However, the set of glycan structures cannot be clearly correlated with levels of glycosyltransferase transcripts in developmental RNA-Seq datasets, but there is an indication for coordinated expression of clusters of potential glycosylation-relevant genes. Thus, there are still questions to be answered in terms of how and why a simple nematode synthesizes such a diverse glycome.
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Affiliation(s)
- Iain B H Wilson
- Department für Chemie, Universität für Bodenkultur, Wien, Austria.
| | - Shi Yan
- Department für Chemie, Universität für Bodenkultur, Wien, Austria; Institut für Parasitologie, Veterinärmedizinische Universität Wien, Wien, Austria
| | - Chunsheng Jin
- Institutionen för Biomedicin, Göteborgs universitet, Göteborg, Sweden
| | | | - Dubravko Rendić
- Department für Chemie, Universität für Bodenkultur, Wien, Austria
| | | | - Ralf Schnabel
- Institut für Genetik, Technische Universität Braunschweig, Braunschweig, Germany
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8
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Intestine-specific removal of DAF-2 nearly doubles lifespan in Caenorhabditis elegans with little fitness cost. Nat Commun 2022; 13:6339. [PMID: 36284093 PMCID: PMC9596710 DOI: 10.1038/s41467-022-33850-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 10/05/2022] [Indexed: 12/25/2022] Open
Abstract
Twenty-nine years following the breakthrough discovery that a single-gene mutation of daf-2 doubles Caenorhabditis elegans lifespan, it remains unclear where this insulin/IGF-1 receptor gene is expressed and where it acts to regulate ageing. Using knock-in fluorescent reporters, we determined that daf-2 and its downstream transcription factor daf-16 are expressed ubiquitously. Using tissue-specific targeted protein degradation, we determined that intracellular DAF-2-to-DAF-16 signaling in the intestine plays a major role in lifespan regulation, while that in the hypodermis, neurons, and germline plays a minor role. Notably, intestine-specific loss of DAF-2 activates DAF-16 in and outside the intestine, causes almost no adverse effects on development and reproduction, and extends lifespan by 94% in a way that partly requires non-intestinal DAF-16. Consistent with intestine supplying nutrients to the entire body, evidence from this and other studies suggests that altered metabolism, particularly down-regulation of protein and RNA synthesis, mediates longevity by reduction of insulin/IGF-1 signaling.
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Xiao L, Fan D, Qi H, Cong Y, Du Z. Defect-buffering cellular plasticity increases robustness of metazoan embryogenesis. Cell Syst 2022; 13:615-630.e9. [PMID: 35882226 DOI: 10.1016/j.cels.2022.07.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 04/14/2022] [Accepted: 06/30/2022] [Indexed: 01/26/2023]
Abstract
Developmental processes are intrinsically robust so as to preserve a normal-like state in response to genetic and environmental fluctuations. However, the robustness and potential phenotypic plasticity of individual developing cells under genetic perturbations remain to be systematically evaluated. Using large-scale gene perturbation, live imaging, lineage tracing, and single-cell phenomics, we quantified the phenotypic landscape of C. elegans embryogenesis in >2,000 embryos following individual knockdown of over 750 conserved genes. We observed that cellular genetic systems are not sufficiently robust to single-gene perturbations across all cells; rather, gene knockdowns frequently induced cellular defects. Dynamic phenotypic analyses revealed many cellular defects to be transient, with cells exhibiting phenotypic plasticity that serves to alleviate, correct, and accommodate the defects. Moreover, potential developmentally related cell modules may buffer the phenotypic effects of individual cell position changes. Our findings reveal non-negligible contributions of cellular plasticity and multicellularity as compensatory strategies to increase developmental robustness.
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Affiliation(s)
- Long Xiao
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Duchangjiang Fan
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Huan Qi
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yulin Cong
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhuo Du
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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10
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Zečić A, Dhondt I, Braeckman BP. Accumulation of Glycogen and Upregulation of LEA-1 in C. elegans daf-2(e1370) Support Stress Resistance, Not Longevity. Cells 2022; 11:245. [PMID: 35053361 PMCID: PMC8773926 DOI: 10.3390/cells11020245] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 12/26/2021] [Accepted: 01/07/2022] [Indexed: 02/04/2023] Open
Abstract
DAF-16-dependent activation of a dauer-associated genetic program in the C. elegans insulin/IGF-1 daf-2(e1370) mutant leads to accumulation of large amounts of glycogen with concomitant upregulation of glycogen synthase, GSY-1. Glycogen is a major storage sugar in C. elegans that can be used as a short-term energy source for survival, and possibly as a reservoir for synthesis of a chemical chaperone trehalose. Its role in mitigating anoxia, osmotic and oxidative stress has been demonstrated previously. Furthermore, daf-2 mutants show increased abundance of the group 3 late embryogenesis abundant protein LEA-1, which has been found to act in synergy with trehalose to exert its protective role against desiccation and heat stress in vitro, and to be essential for desiccation tolerance in C. elegans dauer larvae. Here we demonstrate that accumulated glycogen is not required for daf-2 longevity, but specifically protects against hyperosmotic stress, and serves as an important energy source during starvation. Similarly, lea-1 does not act to support daf-2 longevity. Instead, it contributes to increased resistance of daf-2 mutants to heat, osmotic, and UV stress. In summary, our experimental results suggest that longevity and stress resistance can be uncoupled in IIS longevity mutants.
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Affiliation(s)
| | | | - Bart P. Braeckman
- Laboratory of Aging Physiology and Molecular Evolution, Department of Biology, Ghent University, K. L. Ledeganckstraat 35, B-9000 Ghent, Belgium; (A.Z.); (I.D.)
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11
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Lamassiaude N, Courtot E, Corset A, Charvet CL, Neveu C. Pharmacological characterization of novel heteromeric GluCl subtypes from C. elegans and parasitic nematodes. Br J Pharmacol 2021; 179:1264-1279. [PMID: 34623639 PMCID: PMC9306661 DOI: 10.1111/bph.15703] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 08/30/2021] [Accepted: 09/01/2021] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE Macrocyclic lactones (MLs) are the most widely used broad-spectrum anthelmintic drugs for the treatment of parasitic nematodes impacting both human and animal health. MLs are known to act as agonist of the nematode glutamate-gated chloride channels (GluCls). However, for many important nematode species, the GluCls subunit composition and pharmacological properties remain largely unknown. In order to get new insights about the GluCl diversity and MLs mode of action, we identified and pharmacologically characterized receptors made of highly conserved GluCl subunits from the model nematode Caenorhabditis elegans, the human filarial nematode Brugia malayi and the horse parasite Parascaris univalens. EXPERIMENTAL APPROACH AVR-14, GLC-2, GLC3 and GLC-4 are the most conserved GluCl subunits throughout the Nematoda phylum. For each nematode species, we investigated the ability of these subunits to form either homomeric or heteromeric GluCls when expressed in Xenopus laevis oocytes and performed the detailed pharmacological characterization of the functional channels. KEY RESULTS Here, a total of 14 GluCls have been functionally reconstituted and heteromers formation was inferred from pharmacological criteria. Importantly, we report that the GLC-2 subunit plays a pivotal role in the composition of heteromeric GluCls in nematodes. In addition, we describe a novel GluCl subtype, made of the GLC-2/GLC-3 subunit combination, for which a high concentration of the anthelmintics ivermectin and moxidectin reversibly potentiate glutamate-induced response. CONCLUSION AND IMPLICATIONS This study brings new insights into the diversity of GluCl subtypes in nematodes and promote novel drug targets for the development of next generation anthelmintic compounds.
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Affiliation(s)
| | | | | | | | - Cédric Neveu
- INRAE, Université de Tours, ISP, Nouzilly, France
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12
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Li-Leger E, Feichtinger R, Flibotte S, Holzkamp H, Schnabel R, Moerman DG. Identification of essential genes in Caenorhabditis elegans through whole genome sequencing of legacy mutant collections. G3-GENES GENOMES GENETICS 2021; 11:6373896. [PMID: 34550348 PMCID: PMC8664450 DOI: 10.1093/g3journal/jkab328] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 08/27/2021] [Indexed: 01/23/2023]
Abstract
It has been estimated that 15%–30% of the ∼20,000 genes in C. elegans are essential, yet many of these genes remain to be identified or characterized. With the goal of identifying unknown essential genes, we performed whole-genome sequencing on complementation pairs from legacy collections of maternal-effect lethal and sterile mutants. This approach uncovered maternal genes required for embryonic development and genes with apparent sperm-specific functions. In total, 58 putative essential genes were identified on chromosomes III–V, of which 52 genes are represented by novel alleles in this collection. Of these 52 genes, 19 (40 alleles) were selected for further functional characterization. The terminal phenotypes of embryos were examined, revealing defects in cell division, morphogenesis, and osmotic integrity of the eggshell. Mating assays with wild-type males revealed previously unknown male-expressed genes required for fertilization and embryonic development. The result of this study is a catalog of mutant alleles in essential genes that will serve as a resource to guide further study toward a more complete understanding of this important model organism. As many genes and developmental pathways in C. elegans are conserved and essential genes are often linked to human disease, uncovering the function of these genes may also provide insight to further our understanding of human biology.
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Affiliation(s)
- Erica Li-Leger
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| | - Richard Feichtinger
- Department of Developmental Genetics, Institute of Genetics, Technische Universität Braunschweig, 38106, Germany
| | - Stephane Flibotte
- UBC/LSI Bioinformatics Facility, University of British Columbia, Vancouver, British Columbia, Canada
| | - Heinke Holzkamp
- Department of Developmental Genetics, Institute of Genetics, Technische Universität Braunschweig, 38106, Germany
| | - Ralf Schnabel
- Department of Developmental Genetics, Institute of Genetics, Technische Universität Braunschweig, 38106, Germany
| | - Donald G Moerman
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
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13
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Fry AL, Webster AK, Burnett J, Chitrakar R, Baugh LR, Hubbard EJA. DAF-18/PTEN inhibits germline zygotic gene activation during primordial germ cell quiescence. PLoS Genet 2021; 17:e1009650. [PMID: 34288923 PMCID: PMC8294487 DOI: 10.1371/journal.pgen.1009650] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 06/08/2021] [Indexed: 12/13/2022] Open
Abstract
Quiescence, an actively-maintained reversible state of cell cycle arrest, is not well understood. PTEN is one of the most frequently lost tumor suppressors in human cancers and regulates quiescence of stem cells and cancer cells. The sole PTEN ortholog in Caenorhabditis elegans is daf-18. In a C. elegans loss-of-function mutant for daf-18, primordial germ cells (PGCs) divide inappropriately in L1 larvae hatched into starvation conditions, in a TOR-dependent manner. Here, we further investigated the role of daf-18 in maintaining PGC quiescence in L1 starvation. We found that maternal or zygotic daf-18 is sufficient to maintain cell cycle quiescence, that daf-18 acts in the germ line and soma, and that daf-18 affects timing of PGC divisions in fed animals. Importantly, our results also implicate daf-18 in repression of germline zygotic gene activation, though not in germline fate specification. However, TOR is less important to germline zygotic gene expression, suggesting that in the absence of food, daf-18/PTEN prevents inappropriate germline zygotic gene activation and cell division by distinct mechanisms.
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Affiliation(s)
- Amanda L. Fry
- Skirball Institute of Biomolecular Medicine, Department of Cell Biology, NYU Grossman School of Medicine, New York, New York, United States of America
| | - Amy K. Webster
- Department of Biology, Center for Genomic and Computational Biology, Duke University, Durham, North Carolina, United States of America
| | - Julia Burnett
- Skirball Institute of Biomolecular Medicine, Department of Cell Biology, NYU Grossman School of Medicine, New York, New York, United States of America
| | - Rojin Chitrakar
- Department of Biology, Center for Genomic and Computational Biology, Duke University, Durham, North Carolina, United States of America
| | - L. Ryan Baugh
- Department of Biology, Center for Genomic and Computational Biology, Duke University, Durham, North Carolina, United States of America
| | - E. Jane Albert Hubbard
- Skirball Institute of Biomolecular Medicine, Department of Cell Biology, NYU Grossman School of Medicine, New York, New York, United States of America
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14
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Campos TL, Korhonen PK, Young ND. Cross-Predicting Essential Genes between Two Model Eukaryotic Species Using Machine Learning. Int J Mol Sci 2021; 22:5056. [PMID: 34064595 PMCID: PMC8150380 DOI: 10.3390/ijms22105056] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Revised: 05/07/2021] [Accepted: 05/08/2021] [Indexed: 12/24/2022] Open
Abstract
Experimental studies of Caenorhabditis elegans and Drosophila melanogaster have contributed substantially to our understanding of molecular and cellular processes in metazoans at large. Since the publication of their genomes, functional genomic investigations have identified genes that are essential or non-essential for survival in each species. Recently, a range of features linked to gene essentiality have been inferred using a machine learning (ML)-based approach, allowing essentiality predictions within a species. Nevertheless, predictions between species are still elusive. Here, we undertake a comprehensive study using ML to discover and validate features of essential genes common to both C. elegans and D. melanogaster. We demonstrate that the cross-species prediction of gene essentiality is possible using a subset of features linked to nucleotide/protein sequences, protein orthology and subcellular localisation, single-cell RNA-seq, and histone methylation markers. Complementary analyses showed that essential genes are enriched for transcription and translation functions and are preferentially located away from heterochromatin regions of C. elegans and D. melanogaster chromosomes. The present work should enable the cross-prediction of essential genes between model and non-model metazoans.
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Affiliation(s)
- Tulio L. Campos
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC 3010, Australia; (T.L.C.); (P.K.K.)
- Bioinformatics Core Facility, Instituto Aggeu Magalhães, Fundação Oswaldo Cruz (IAM-Fiocruz), Recife 50740-465, PE, Brazil
| | - Pasi K. Korhonen
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC 3010, Australia; (T.L.C.); (P.K.K.)
| | - Neil D. Young
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC 3010, Australia; (T.L.C.); (P.K.K.)
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15
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Rasulova M, Zečić A, Monje Moreno JM, Vandemeulebroucke L, Dhondt I, Braeckman BP. Elevated Trehalose Levels in C. elegans daf-2 Mutants Increase Stress Resistance, Not Lifespan. Metabolites 2021; 11:metabo11020105. [PMID: 33673074 PMCID: PMC7917784 DOI: 10.3390/metabo11020105] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 02/04/2021] [Accepted: 02/10/2021] [Indexed: 12/20/2022] Open
Abstract
The C. elegans insulin/IGF-1 (insulin-like growth factor 1) signaling mutant daf-2 recapitulates the dauer metabolic signature—a shift towards lipid and carbohydrate accumulation—which may be linked to its longevity and stress resistance phenotypes. Trehalose, a disaccharide of glucose, is highly upregulated in daf‑2 mutants and it has been linked to proteome stabilization and protection against heat, cold, desiccation, and hypoxia. Earlier studies suggested that elevated trehalose levels can explain up to 43% of the lifespan extension observed in daf-2 mutants. Here we demonstrate that trehalose accumulation is responsible for increased osmotolerance, and to some degree thermotolerance, rather than longevity in daf-2 mutants. This indicates that particular stress resistance phenotypes can be uncoupled from longevity.
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16
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Ancestral function of Inhibitors-of-kappaB regulates Caenorhabditis elegans development. Sci Rep 2020; 10:16153. [PMID: 32999373 PMCID: PMC7527347 DOI: 10.1038/s41598-020-73146-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 09/10/2020] [Indexed: 01/08/2023] Open
Abstract
Mammalian IκB proteins (IκBs) exert their main function as negative regulators of NF-κB, a central signaling pathway controlling immunity and inflammation. An alternative chromatin role for IκBs has been shown to affect stemness and cell differentiation. However, the involvement of NF-κB in this function has not been excluded. NFKI-1 and IKB-1 are IκB homologs in Caenorhabditis elegans, which lacks NF-κB nuclear effectors. We found that nfki-1 and ikb-1 mutants display developmental defects that phenocopy mutations in Polycomb and UTX-1 histone demethylase, suggesting a role for C. elegans IκBs in chromatin regulation. Further supporting this possibility (1) we detected NFKI-1 in the nucleus of cells; (2) NFKI-1 and IKB-1 bind to histones and Polycomb proteins, (3) and associate with chromatin in vivo, and (4) mutations in nfki-1 and ikb-1 alter chromatin marks. Based on these results, we propose that ancestral IκB inhibitors modulate Polycomb activity at specific gene subsets with an impact on development.
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17
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Campos TL, Korhonen PK, Sternberg PW, Gasser RB, Young ND. Predicting gene essentiality in Caenorhabditis elegans by feature engineering and machine-learning. Comput Struct Biotechnol J 2020; 18:1093-1102. [PMID: 32489524 PMCID: PMC7251299 DOI: 10.1016/j.csbj.2020.05.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 05/01/2020] [Accepted: 05/06/2020] [Indexed: 02/08/2023] Open
Abstract
Defining genes that are essential for life has major implications for understanding critical biological processes and mechanisms. Although essential genes have been identified and characterised experimentally using functional genomic tools, it is challenging to predict with confidence such genes from molecular and phenomic data sets using computational methods. Using extensive data sets available for the model organism Caenorhabditis elegans, we constructed here a machine-learning (ML)-based workflow for the prediction of essential genes on a genome-wide scale. We identified strong predictors for such genes and showed that trained ML models consistently achieve highly-accurate classifications. Complementary analyses revealed an association between essential genes and chromosomal location. Our findings reveal that essential genes in C. elegans tend to be located in or near the centre of autosomal chromosomes; are positively correlated with low single nucleotide polymorphim (SNP) densities and epigenetic markers in promoter regions; are involved in protein and nucleotide processing; are transcribed in most cells; are enriched in reproductive tissues or are targets for small RNAs bound to the argonaut CSR-1. Based on these results, we hypothesise an interplay between epigenetic markers and small RNA pathways in the germline, with transcription-based memory; this hypothesis warrants testing. From a technical perspective, further work is needed to evaluate whether the present ML-based approach will be applicable to other metazoans (including Drosophila melanogaster) for which comprehensive data sets (i.e. genomic, transcriptomic, proteomic, variomic, epigenetic and phenomic) are available.
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Key Words
- CDS, coding sequence
- CRISPR, Clustered Regularly Interspaced Short Palindromic Repeats
- Caenorhabditis elegans
- ES, Essentiality Score
- EST, expressed sequence tag
- Essential genes
- Essentiality predictions
- GBM, Gradient Boosting Method
- GFF, general feature format
- GLM, Generalised Linear Model
- GO, gene ontology
- ML, machine-learning
- Machine-learning
- NN, Artificial Neural Network
- PPI, protein-protein interaction
- PR-AUC, Area Under the Precision-Recall Curve
- RF, Random Forest
- RNAi, RNA interference
- ROC-AUC, Area Under the Receiver Operating Characteristic Curve
- SNP, single nucleotide polymorphism
- SPLS, Sparse Partial Least Squares
- SVM, Support-Vector Machine
- TEA, Tissue Enrichment Analysis tool (WormBase)
- TSS, transcription start site
- VCF, variant call file
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Affiliation(s)
- Tulio L Campos
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia.,Instituto Aggeu Magalhães, Fundação Oswaldo Cruz (IAM-Fiocruz), Recife, Pernambuco, Brazil
| | - Pasi K Korhonen
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Paul W Sternberg
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States
| | - Robin B Gasser
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Neil D Young
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia
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18
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Taffoni C, Omi S, Huber C, Mailfert S, Fallet M, Rupprecht JF, Ewbank JJ, Pujol N. Microtubule plus-end dynamics link wound repair to the innate immune response. eLife 2020; 9:e45047. [PMID: 31995031 PMCID: PMC7043892 DOI: 10.7554/elife.45047] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 01/27/2020] [Indexed: 01/20/2023] Open
Abstract
The skin protects animals from infection and physical damage. In Caenorhabditis elegans, wounding the epidermis triggers an immune reaction and a repair response, but it is not clear how these are coordinated. Previous work implicated the microtubule cytoskeleton in the maintenance of epidermal integrity (Chuang et al., 2016). Here, by establishing a simple wounding system, we show that wounding provokes a reorganisation of plasma membrane subdomains. This is followed by recruitment of the microtubule plus end-binding protein EB1/EBP-2 around the wound and actin ring formation, dependent on ARP2/3 branched actin polymerisation. We show that microtubule dynamics are required for the recruitment and closure of the actin ring, and for the trafficking of the key signalling protein SLC6/SNF-12 toward the injury site. Without SNF-12 recruitment, there is an abrogation of the immune response. Our results suggest that microtubule dynamics coordinate the cytoskeletal changes required for wound repair and the concomitant activation of innate immunity.
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Affiliation(s)
- Clara Taffoni
- CIML, Centre d’Immunologie de Marseille-Luminy, Turing Centre for Living SystemsAix Marseille Univ, INSERM, CNRSMarseilleFrance
| | - Shizue Omi
- CIML, Centre d’Immunologie de Marseille-Luminy, Turing Centre for Living SystemsAix Marseille Univ, INSERM, CNRSMarseilleFrance
| | - Caroline Huber
- CIML, Centre d’Immunologie de Marseille-Luminy, Turing Centre for Living SystemsAix Marseille Univ, INSERM, CNRSMarseilleFrance
| | - Sébastien Mailfert
- CIML, Centre d’Immunologie de Marseille-Luminy, Turing Centre for Living SystemsAix Marseille Univ, INSERM, CNRSMarseilleFrance
| | - Mathieu Fallet
- CIML, Centre d’Immunologie de Marseille-Luminy, Turing Centre for Living SystemsAix Marseille Univ, INSERM, CNRSMarseilleFrance
| | | | - Jonathan J Ewbank
- CIML, Centre d’Immunologie de Marseille-Luminy, Turing Centre for Living SystemsAix Marseille Univ, INSERM, CNRSMarseilleFrance
| | - Nathalie Pujol
- CIML, Centre d’Immunologie de Marseille-Luminy, Turing Centre for Living SystemsAix Marseille Univ, INSERM, CNRSMarseilleFrance
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19
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Otero L, Martínez-Rosales C, Barrera E, Pantano S, Salinas G. Complex I and II Subunit Gene Duplications Provide Increased Fitness to Worms. Front Genet 2019; 10:1043. [PMID: 31781156 PMCID: PMC6859908 DOI: 10.3389/fgene.2019.01043] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 09/30/2019] [Indexed: 11/20/2022] Open
Abstract
Helminths use an alternative mitochondrial electron transport chain (ETC) under hypoxic conditions, such as those found in the gastrointestinal tract. In this alternative ETC, fumarate is the final electron acceptor and rhodoquinone (RQ) serves as an electron carrier. RQ receives electrons from reduced nicotinamide adenine dinucleotide through complex I and donates electrons to fumarate through complex II. In this latter reaction, complex II functions in the opposite direction to the conventional ETC (i.e., as fumarate reductase instead of succinate dehydrogenase). Studies in Ascaris suum indicate that this is possible due to changes in complex II, involving alternative succinate dehydrogenase (SDH) subunits SDHA and SDHD, derived from duplicated genes. We analyzed helminth genomes and found that distinct lineages have different gene duplications of complex II subunits (SDHA, SDHB, SDHC, and SDHD). Similarly, we found lineage-specific duplications in genes encoding complex I subunits that interact with quinones (NDUF2 and NDUF7). The phylogenetic analysis of ETC subunits revealed a complex history with independent evolutionary events involving gene duplications and losses. Our results indicated that there is not a common evolutionary event related to ETC subunit genes linked to RQ. The free-living nematode Caenorhabditis elegans uses RQ and has two genes encoding SDHA (sdha-1 and sdha-2) and two genes encoding NDUF2 (nduf2-1 and nduf2-2). sdha-1 and nduf2-1 are essential genes and have a similar expression pattern during C. elegans lifecycle. Using knockout strains, we found that sdha-2 and nduf2-2 are not essential, even in hypoxia. Yet, sdha-2 and nduf2-2 expression is increased in the early embryo and in dauer larvae, stages where there is low oxygen tension. Strikingly, sdha-1 and sdha-2 as well as nduf2-1 and nduf2-2 showed inverted expression profiles during the C. elegans life cycle. Finally, we found that sdha-2 and nduf2-2 knockout mutant strain progeny is affected. Our results indicate that different complex I and II subunit gene duplications provide increased fitness to worms.
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Affiliation(s)
- Lucía Otero
- Laboratorio de Biología de Gusanos, Unidad Mixta Departamento de Biociencias, Facultad de Química, Universidad de la República–Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Cecilia Martínez-Rosales
- Laboratorio de Biología de Gusanos, Unidad Mixta Departamento de Biociencias, Facultad de Química, Universidad de la República–Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Exequiel Barrera
- Laboratorio de Simulaciones Biomoleculares, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Sergio Pantano
- Laboratorio de Simulaciones Biomoleculares, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Gustavo Salinas
- Laboratorio de Biología de Gusanos, Unidad Mixta Departamento de Biociencias, Facultad de Química, Universidad de la República–Institut Pasteur de Montevideo, Montevideo, Uruguay
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20
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Hahnel SR, Zdraljevic S, Rodriguez BC, Zhao Y, McGrath PT, Andersen EC. Extreme allelic heterogeneity at a Caenorhabditis elegans beta-tubulin locus explains natural resistance to benzimidazoles. PLoS Pathog 2018; 14:e1007226. [PMID: 30372484 PMCID: PMC6224181 DOI: 10.1371/journal.ppat.1007226] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 11/08/2018] [Accepted: 10/01/2018] [Indexed: 12/22/2022] Open
Abstract
Benzimidazoles (BZ) are essential components of the limited chemotherapeutic arsenal available to control the global burden of parasitic nematodes. The emerging threat of BZ resistance among multiple nematode species necessitates the development of novel strategies to identify genetic and molecular mechanisms underlying this resistance. All detection of parasitic helminth resistance to BZ is focused on the genotyping of three variant sites in the orthologs of the β-tubulin gene found to confer resistance in the free-living nematode Caenorhabditis elegans. Because of the limitations of laboratory and field experiments in parasitic nematodes, it is difficult to look beyond these three sites to identify additional mechanisms that might contribute to BZ resistance in the field. Here, we took an unbiased genome-wide mapping approach in the free-living nematode species C. elegans to identify the genetic underpinnings of natural resistance to the commonly used BZ, albendazole (ABZ). We found a wide range of natural variation in ABZ resistance in natural C. elegans populations. In agreement with known mechanisms of BZ resistance in parasites, we found that a majority of the variation in ABZ resistance among wild C. elegans strains is caused by variation in the β-tubulin gene ben-1. This result shows empirically that resistance to ABZ naturally exists and segregates within the C. elegans population, suggesting that selection in natural niches could enrich for resistant alleles. We identified 25 distinct ben-1 alleles that are segregating at low frequencies within the C. elegans population, including many novel molecular variants. Population genetic analyses indicate that ben-1 variation arose multiple times during the evolutionary history of C. elegans and provide evidence that these alleles likely occurred recently because of local selective pressures. Additionally, we find purifying selection at all five β-tubulin genes, despite predicted loss-of-function variants in ben-1, indicating that BZ resistance in natural niches is a stronger selective pressure than loss of one β-tubulin gene. Furthermore, we used genome-editing to show that the most common parasitic nematode β-tubulin allele that confers BZ resistance, F200Y, confers resistance in C. elegans. Importantly, we identified a novel genomic region that is correlated with ABZ resistance in the C. elegans population but independent of ben-1 and the other β-tubulin loci, suggesting that there are multiple mechanisms underlying BZ resistance. Taken together, our results establish a population-level resource of nematode natural diversity as an important model for the study of mechanisms that give rise to BZ resistance.
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Affiliation(s)
- Steffen R. Hahnel
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, United States of America
| | - Stefan Zdraljevic
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, United States of America
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, United States of America
| | - Briana C. Rodriguez
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, United States of America
| | - Yuehui Zhao
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Patrick T. McGrath
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Erik C. Andersen
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, United States of America
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, United States of America
- Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Chicago, IL, United States of America
- * E-mail:
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21
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Xia T, Horton ER, Salcini AE, Pocock R, Cox TR, Erler JT. Proteomic Characterization of Caenorhabditis elegans Larval Development. Proteomics 2017; 18. [PMID: 29178193 DOI: 10.1002/pmic.201700238] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 11/03/2017] [Indexed: 11/06/2022]
Abstract
The nematode Caenorhabditis elegans is widely used as a model organism to study cell and developmental biology. Quantitative proteomics of C. elegans is still in its infancy and, so far, most studies have been performed on adult worm samples. Here, we used quantitative mass spectrometry to characterize protein level changes across the four larval developmental stages (L1-L4) of C. elegans. In total, we identified 4130 proteins, and quantified 1541 proteins that were present across all four stages in three biological replicates from independent experiments. Using hierarchical clustering and functional ontological analyses, we identified 21 clusters containing proteins with similar protein profiles across the four stages, and highlighted the most overrepresented biological functions in each of these protein clusters. In addition, we used the dataset to identify putative larval stage-specific proteins in each individual developmental stage, as well as in the early and late developmental stages. In summary, this dataset provides system-wide analysis of protein level changes across the four C. elegans larval developmental stages, which serves as a useful resource for the C. elegans research community. MS data were deposited in ProteomeXchange (http://proteomecentral.proteomexchange.org) via the PRIDE partner repository with the primary accession identifier PXD006676.
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Affiliation(s)
- Tian Xia
- Biotech Research and Innovation Centre, University of Copenhagen, Copenhagen, Denmark
| | - Edward R Horton
- Biotech Research and Innovation Centre, University of Copenhagen, Copenhagen, Denmark
| | | | - Roger Pocock
- Department of Anatomy and Developmental Biology, Development and Stem Cells Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Australia
| | - Thomas R Cox
- Biotech Research and Innovation Centre, University of Copenhagen, Copenhagen, Denmark.,Cancer Division, Garvan Institute of Medical Research and The Kinghorn Cancer Centre, St Vincent's Clinical School, Faculty of Medicine, UNSW Sydney, Sydney, Australia
| | - Janine T Erler
- Biotech Research and Innovation Centre, University of Copenhagen, Copenhagen, Denmark
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