1
|
Pees B, Peters L, Treitz C, Hamerich IK, Kissoyan KAB, Tholey A, Dierking K. The Caenorhabditis elegans proteome response to two protective Pseudomonas symbionts. mBio 2024; 15:e0346323. [PMID: 38411078 PMCID: PMC11005407 DOI: 10.1128/mbio.03463-23] [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: 01/04/2024] [Accepted: 02/05/2024] [Indexed: 02/28/2024] Open
Abstract
The Caenorhabditis elegans natural microbiota isolates Pseudomonas lurida MYb11 and Pseudomonas fluorescens MYb115 protect the host against pathogens through distinct mechanisms. While P. lurida produces an antimicrobial compound and directly inhibits pathogen growth, P. fluorescens MYb115 protects the host without affecting pathogen growth. It is unknown how these two protective microbes affect host biological processes. We used a proteomics approach to elucidate the C. elegans response to MYb11 and MYb115. We found that both Pseudomonas isolates increase vitellogenin protein production in young adults, which confirms previous findings on the effect of microbiota on C. elegans reproductive timing. Moreover, the C. elegans responses to MYb11 and MYb115 exhibit common signatures with the response to other vitamin B12-producing bacteria, emphasizing the importance of vitamin B12 in C. elegans-microbe metabolic interactions. We further analyzed signatures in the C. elegans response specific to MYb11 or MYb115. We provide evidence for distinct modifications in lipid metabolism by both symbiotic microbes. We could identify the activation of host-pathogen defense responses as an MYb11-specific proteome signature and provide evidence that the intermediate filament protein IFB-2 is required for MYb115-mediated protection. These results indicate that MYb11 not only produces an antimicrobial compound but also activates host antimicrobial defenses, which together might increase resistance to infection. In contrast, MYb115 affects host processes such as lipid metabolism and cytoskeleton dynamics, which might increase host tolerance to infection. Overall, this study pinpoints proteins of interest that form the basis for additional exploration into the mechanisms underlying C. elegans microbiota-mediated protection from pathogen infection and other microbiota-mediated traits.IMPORTANCESymbiotic bacteria can defend their host against pathogen infection. While some protective symbionts directly interact with pathogenic bacteria, other protective symbionts elicit a response in the host that improves its own pathogen defenses. To better understand how a host responds to protective symbionts, we examined which host proteins are affected by two protective Pseudomonas bacteria in the model nematode Caenorhabditis elegans. We found that the C. elegans response to its protective symbionts is manifold, which was reflected in changes in proteins that are involved in metabolism, the immune system, and cell structure. This study provides a foundation for exploring the contribution of the host response to symbiont-mediated protection from pathogen infection.
Collapse
Affiliation(s)
- Barbara Pees
- Department of Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrecht University, Kiel, Germany
| | - Lena Peters
- Department of Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrecht University, Kiel, Germany
| | - Christian Treitz
- Systematic Proteome Research and Bioanalytics, Institute for Experimental Medicine, Christian-Albrecht University, Kiel, Germany
| | - Inga K. Hamerich
- Department of Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrecht University, Kiel, Germany
| | - Kohar A. B. Kissoyan
- Department of Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrecht University, Kiel, Germany
| | - Andreas Tholey
- Systematic Proteome Research and Bioanalytics, Institute for Experimental Medicine, Christian-Albrecht University, Kiel, Germany
| | - Katja Dierking
- Department of Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrecht University, Kiel, Germany
| |
Collapse
|
2
|
Feng D, Qu L, Powell-Coffman JA. Transcriptome analyses describe the consequences of persistent HIF-1 over-activation in Caenorhabditis elegans. PLoS One 2024; 19:e0295093. [PMID: 38517909 PMCID: PMC10959373 DOI: 10.1371/journal.pone.0295093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 02/20/2024] [Indexed: 03/24/2024] Open
Abstract
Metazoan animals rely on oxygen for survival, but during normal development and homeostasis, animals are often challenged by hypoxia (low oxygen). In metazoans, many of the critical hypoxia responses are mediated by the evolutionarily conserved hypoxia-inducible transcription factors (HIFs). The stability and activity of HIF complexes are strictly regulated. In the model organism C. elegans, HIF-1 stability and activity are negatively regulated by VHL-1, EGL-9, RHY-1 and SWAN-1. Importantly, C. elegans mutants carrying strong loss-of-function mutations in these genes are viable, and this provides opportunities to interrogate the molecular consequences of persistent HIF-1 over-activation. We find that the genome-wide gene expression patterns are compellingly similar in these mutants, supporting models in which RHY-1, VHL-1 and EGL-9 function in common pathway(s) to regulate HIF-1 activity. These studies illuminate the diversified biological roles played by HIF-1, including metabolism and stress response. Genes regulated by persistent HIF-1 over-activation overlap with genes responsive to pathogens, and they overlap with genes regulated by DAF-16. As crucial stress regulators, HIF-1 and DAF-16 converge on key stress-responsive genes and function synergistically to enable hypoxia survival.
Collapse
Affiliation(s)
- Dingxia Feng
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa, United States of America
| | - Long Qu
- Department of Statistics, Iowa State University, Ames, Iowa, United States of America
| | - Jo Anne Powell-Coffman
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa, United States of America
| |
Collapse
|
3
|
Feng D, Qu L. Transcriptome analyses describe the consequences of persistent HIF-1 over-activation in Caenorhabditis elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.15.567311. [PMID: 38014086 PMCID: PMC10680707 DOI: 10.1101/2023.11.15.567311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Metazoan animals rely on oxygen for survival, but during normal development and homeostasis, animals are often challenged by hypoxia (low oxygen). In metazoans, many of the critical hypoxia responses are mediated by the evolutionarily conserved hypoxia-inducible transcription factors (HIFs). The stability and activity of HIF complexes are strictly regulated. In the model organism C. elegans, HIF-1 stability and activity are negatively regulated by VHL-1, EGL-9, RHY-1 and SWAN-1. Importantly, C. elegans mutants carrying strong loss-of-function mutations in these genes are viable, and this provides opportunities to interrogate the molecular consequences of persistent HIF-1 over-activation. We find that the genome-wide gene expression patterns are compellingly similar in these mutants, supporting models in which RHY-1, SWAN-1 and EGL-9 function in common pathway(s) to regulate HIF-1 activity. These studies illuminate the diversified biological roles played by HIF-1, including metabolism, hypoxia and other stress responses, reproduction and development. Genes regulated by persistent HIF-1 over-activation overlap with genes responsive to pathogens, and they overlap with genes regulated by DAF-16. As crucial stress regulators, HIF-1 and DAF-16 converge on key stress-responsive genes and function synergistically to enable hypoxia survival.
Collapse
Affiliation(s)
- Dingxia Feng
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa, United States of America
| | - Long Qu
- Department of Statistics, Iowa State University, Ames, Iowa, United States of America
| |
Collapse
|
4
|
Yamamoto KK, Savage-Dunn C. TGF-β pathways in aging and immunity: lessons from Caenorhabditis elegans. Front Genet 2023; 14:1220068. [PMID: 37732316 PMCID: PMC10507863 DOI: 10.3389/fgene.2023.1220068] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 08/23/2023] [Indexed: 09/22/2023] Open
Abstract
The Transforming Growth Factor-β (TGF-β) superfamily of signaling molecules plays critical roles in development, differentiation, homeostasis, and disease. Due to the conservation of these ligands and their signaling pathways, genetic studies in invertebrate systems including the nematode Caenorhabditis elegans have been instrumental in identifying signaling mechanisms. C. elegans is also a premier organism for research in longevity and healthy aging. Here we summarize current knowledge on the roles of TGF-β signaling in aging and immunity.
Collapse
Affiliation(s)
| | - Cathy Savage-Dunn
- Department of Biology, Queens College, and PhD Program in Biology, The Graduate Center, City University of New York, New York City, NY, United States
| |
Collapse
|
5
|
Larigot L, Mansuy D, Borowski I, Coumoul X, Dairou J. Cytochromes P450 of Caenorhabditis elegans: Implication in Biological Functions and Metabolism of Xenobiotics. Biomolecules 2022; 12:biom12030342. [PMID: 35327534 PMCID: PMC8945457 DOI: 10.3390/biom12030342] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 02/17/2022] [Accepted: 02/17/2022] [Indexed: 02/01/2023] Open
Abstract
Caenorhabditis elegans is an important model used for many aspects of biological research. Its genome contains 76 genes coding for cytochromes P450 (P450s), and few data about the biochemical properties of those P450s have been published so far. However, an increasing number of articles have appeared on their involvement in the metabolism of xenobiotics and endobiotics such as fatty acid derivatives and steroids. Moreover, the implication of some P450s in various biological functions of C. elegans, such as survival, dauer formation, life span, fat content, or lipid metabolism, without mention of the precise reaction catalyzed by those P450s, has been reported in several articles. This review presents the state of our knowledge about C. elegans P450s.
Collapse
Affiliation(s)
- Lucie Larigot
- Campus Saint Germain, INSERM UMR-S 1124, Université de Paris, 45 rue des Saints-Pères, 75006 Paris, France;
| | - Daniel Mansuy
- Laboratoire de Chimie et de Biochimie Pharmacologiques et Toxicologiques, CNRS, Université de Paris, 75006 Paris, France; (D.M.); (I.B.)
| | - Ilona Borowski
- Laboratoire de Chimie et de Biochimie Pharmacologiques et Toxicologiques, CNRS, Université de Paris, 75006 Paris, France; (D.M.); (I.B.)
| | - Xavier Coumoul
- Campus Saint Germain, INSERM UMR-S 1124, Université de Paris, 45 rue des Saints-Pères, 75006 Paris, France;
- Correspondence: (X.C.) or (J.D.); Tel.: +331-76-53-42-35; Fax: + 331-42-86-43-84
| | - Julien Dairou
- Laboratoire de Chimie et de Biochimie Pharmacologiques et Toxicologiques, CNRS, Université de Paris, 75006 Paris, France; (D.M.); (I.B.)
- Correspondence: (X.C.) or (J.D.); Tel.: +331-76-53-42-35; Fax: + 331-42-86-43-84
| |
Collapse
|
6
|
Homocysteine-Thiolactone Modulates Gating of Mitochondrial Voltage-Dependent Anion Channel (VDAC) and Protects It from Induced Oxidative Stress. J Membr Biol 2022; 255:79-97. [PMID: 35103807 DOI: 10.1007/s00232-022-00215-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 01/10/2022] [Indexed: 12/26/2022]
Abstract
The gating of the Voltage-Dependent Anion Channel (VDAC) is linked to oxidative stress through increased generation of mitochondrial ROS with increasing mitochondrial membrane potential (ΔΨm). It has been already reported that H2O2 increases the single-channel conductance of VDAC on a bilayer lipid membrane. On the other hand, homocysteine (Hcy) has been reported to induce mitochondria-mediated cell death. It is argued that the thiol-form of homocysteine, HTL could be the plausible molecule responsible for the alteration in the function of proteins, such as VDAC. It is hypothesized that HTL interacts with VDAC that causes functional abnormalities. An investigation was undertaken to study the interaction of HTL with VDAC under H2O2 induced oxidative stress through biophysical and electrophysiological methods. Fluorescence spectroscopic studies indicate that HTL interacts with VDAC, but under induced oxidative stress the effect is prevented partially. Similarly, bilayer electrophysiology studies suggest that HTL shows a reduction in VDAC single-channel conductance, but the effects are partially prevented under an oxidative environment. Gly172 and His181 are predicted through bioinformatics tools to be the most plausible binding residues of HTL in Rat VDAC. The binding of HTL and H2O2 with VDAC appears to be cooperative as per our analysis of experimental data in the light of the Hill-Langmuir equation. The binding energies are estimated to be - 4.7 kcal mol-1 and - 2.8 kcal mol-1, respectively. The present in vitro studies suggest that when mitochondrial VDAC is under oxidative stress, the effects of amino acid metabolites like HTL are suppressed.
Collapse
|
7
|
Khanna A, Sellegounder D, Kumar J, Chamoli M, Vargas M, Chinta SJ, Rane A, Nelson C, Peiris TH, Brem R, Andersen J, Lithgow G, Kapahi P. Trimethylamine modulates dauer formation, neurodegeneration, and lifespan through tyra-3/daf-11 signaling in Caenorhabditis elegans. Aging Cell 2021; 20:e13351. [PMID: 33819374 PMCID: PMC8135002 DOI: 10.1111/acel.13351] [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: 05/20/2020] [Revised: 02/10/2021] [Accepted: 03/05/2021] [Indexed: 11/27/2022] Open
Abstract
In the nematode Caenorhabditis elegans, signals derived from bacteria in the diet, the animal's major nutrient source, can modulate both behavior and healthspan. Here we describe a dual role for trimethylamine (TMA), a human gut flora metabolite, which acts as a nutrient signal and a neurotoxin. TMA and its associated metabolites are produced by the human gut microbiome and have been suggested to serve as risk biomarkers for diabetes and cardiovascular diseases. We demonstrate that the tyramine receptor TYRA-3, a conserved G protein-coupled receptor (GPCR), is required to sense TMA and mediate its responses. TMA activates guanylyl cyclase DAF-11 signaling through TYRA-3 in amphid neurons (ASK) and ciliated neurons (BAG) to mediate food-sensing behavior. Bacterial mutants deficient in TMA production enhance dauer formation, extend lifespan, and are less preferred as a food source. Increased levels of TMA lead to neural damage in models of Parkinson's disease and shorten lifespan. Our results reveal conserved signaling pathways modulated by TMA in C. elegans that are likely to be relevant for its effects in mammalian systems.
Collapse
Affiliation(s)
- Amit Khanna
- Buck Institute for Research on Aging Novato CA USA
- Dovetail Genomics LLC Scotts Valley CA USA
| | | | | | | | | | - Shankar J. Chinta
- Buck Institute for Research on Aging Novato CA USA
- Touro University California Vallejo CA USA
| | - Anand Rane
- Buck Institute for Research on Aging Novato CA USA
| | | | | | - Rachel Brem
- Buck Institute for Research on Aging Novato CA USA
| | | | | | | |
Collapse
|
8
|
Li YX, Wang NN, Zhou YX, Lin CG, Wu JS, Chen XQ, Chen GJ, Du ZJ. Planococcus maritimus ML1206 Isolated from Wild Oysters Enhances the Survival of Caenorhabditis elegans against Vibrio anguillarum. Mar Drugs 2021; 19:md19030150. [PMID: 33809116 PMCID: PMC7999227 DOI: 10.3390/md19030150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 03/05/2021] [Accepted: 03/09/2021] [Indexed: 11/16/2022] Open
Abstract
With the widespread occurrence of aquaculture diseases and the broad application of antibiotics, drug-resistant pathogens have increasingly affected aquatic animals’ health. Marine probiotics, which live under high pressure in a saltwater environment, show high potential as a substitute for antibiotics in the field of aquatic disease control. In this study, twenty strains of non-hemolytic bacteria were isolated from the intestine of wild oysters and perch, and a model of Caenorhabditis elegans infected by Vibrio anguillarum was established. Based on the model, ML1206, which showed a 99% similarity of 16S rRNA sequence to Planococcus maritimus, was selected as a potential marine probiotic, with strong antibacterial capabilities and great acid and bile salt tolerance, to protect Caenorhabditis elegans from being damaged by Vibrio anguillarum. Combined with plate counting and transmission electron microscopy, it was found that strain ML1206 could significantly inhibit Vibrio anguillarum colonization in the intestinal tract of Caenorhabditis elegans. Acute oral toxicity tests in mice showed that ML1206 was safe and non-toxic. The real-time qPCR results showed a higher expression level of genes related to the antibacterial peptide (ilys-3) and detoxification (ugt-22, cyp-35A3, and cyp-14A3) in the group of Caenorhabditis elegans protected by ML1206 compared to the control group. It is speculated that ML1206, as a potential probiotic, may inhibit the infection caused by Vibrio anguillarum through stimulating Caenorhabditis elegans to secrete antibacterial effectors and detoxification proteins. This paper provides a new direction for screening marine probiotics and an experimental basis to support the potential application of ML1206 as a marine probiotic in aquaculture.
Collapse
Affiliation(s)
- Ying-Xiu Li
- Marine College, Shandong University, Weihai 264209, China; (Y.-X.L.); (N.-N.W.); (Y.-X.Z.); (C.-G.L.); (J.-S.W.); (X.-Q.C.)
| | - Nan-Nan Wang
- Marine College, Shandong University, Weihai 264209, China; (Y.-X.L.); (N.-N.W.); (Y.-X.Z.); (C.-G.L.); (J.-S.W.); (X.-Q.C.)
| | - Yan-Xia Zhou
- Marine College, Shandong University, Weihai 264209, China; (Y.-X.L.); (N.-N.W.); (Y.-X.Z.); (C.-G.L.); (J.-S.W.); (X.-Q.C.)
| | - Chun-Guo Lin
- Marine College, Shandong University, Weihai 264209, China; (Y.-X.L.); (N.-N.W.); (Y.-X.Z.); (C.-G.L.); (J.-S.W.); (X.-Q.C.)
| | - Jing-Shan Wu
- Marine College, Shandong University, Weihai 264209, China; (Y.-X.L.); (N.-N.W.); (Y.-X.Z.); (C.-G.L.); (J.-S.W.); (X.-Q.C.)
| | - Xin-Qi Chen
- Marine College, Shandong University, Weihai 264209, China; (Y.-X.L.); (N.-N.W.); (Y.-X.Z.); (C.-G.L.); (J.-S.W.); (X.-Q.C.)
| | - Guan-Jun Chen
- Marine College, Shandong University, Weihai 264209, China; (Y.-X.L.); (N.-N.W.); (Y.-X.Z.); (C.-G.L.); (J.-S.W.); (X.-Q.C.)
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, China
- Correspondence: (G.J.C.); (Z.-J.D.)
| | - Zong-Jun Du
- Marine College, Shandong University, Weihai 264209, China; (Y.-X.L.); (N.-N.W.); (Y.-X.Z.); (C.-G.L.); (J.-S.W.); (X.-Q.C.)
- State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, China
- Correspondence: (G.J.C.); (Z.-J.D.)
| |
Collapse
|
9
|
Palominos MF, Verdugo L, Gabaldon C, Pollak B, Ortíz-Severín J, Varas MA, Chávez FP, Calixto A. Transgenerational Diapause as an Avoidance Strategy against Bacterial Pathogens in Caenorhabditis elegans. mBio 2017; 8:e01234-17. [PMID: 29018118 PMCID: PMC5635688 DOI: 10.1128/mbio.01234-17] [Citation(s) in RCA: 40] [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: 07/14/2017] [Accepted: 08/30/2017] [Indexed: 12/22/2022] Open
Abstract
The dynamic response of organisms exposed to environmental pathogens determines their survival or demise, and the outcome of this interaction depends on the host's susceptibility and pathogen-dependent virulence factors. The transmission of acquired information about the nature of a pathogen to progeny may ensure effective defensive strategies for the progeny's survival in adverse environments. Environmental RNA interference (RNAi) is a systemic and heritable mechanism and has recently been linked to antibacterial and antifungal defenses in both plants and animals. Here, we report that the second generation of Caenorhabditis elegans living on pathogenic bacteria can avoid bacterial infection by entering diapause in an RNAi pathway-dependent mechanism. Furthermore, we demonstrate that the information encoding this survival strategy is transgenerationally transmitted to the progeny via the maternal germ line.IMPORTANCE Bacteria vastly influence physiology and behavior, and yet, the specific mechanisms by which they cause behavioral changes in hosts are not known. We use C. elegans as a host and the bacteria they eat to understand how microbes trigger a behavioral change that helps animals to survive. We found that animals faced with an infection for two generations could enter a hibernationlike state, arresting development by forming dauer larvae. Dauers have closed mouths and effectively avoid infection. Animals accumulate information that is transgenerationally transmitted to the next generations to form dauers. This work gives insight on how bacteria communicate in noncanonical ways with their hosts, resulting in long-lasting effects providing survival strategies to the community.
Collapse
Affiliation(s)
- M Fernanda Palominos
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Lidia Verdugo
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago, Chile
| | - Carolaing Gabaldon
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago, Chile
| | - Bernardo Pollak
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Javiera Ortíz-Severín
- Laboratorio de Microbiología de Sistemas, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Macarena A Varas
- Laboratorio de Microbiología de Sistemas, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Francisco P Chávez
- Laboratorio de Microbiología de Sistemas, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Andrea Calixto
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago, Chile
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| |
Collapse
|
10
|
Ren M, Zhao L, Lv X, Wang D. Antimicrobial proteins in the response to graphene oxide in Caenorhabditis elegans. Nanotoxicology 2017; 11:578-590. [DOI: 10.1080/17435390.2017.1329954] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Mingxia Ren
- Key Laboratory of Environmental Medicine Engineering in Ministry of Education, Medical School, Southeast University, Nanjing, China
| | - Li Zhao
- Key Laboratory of Environmental Medicine Engineering in Ministry of Education, Medical School, Southeast University, Nanjing, China
| | - Xiao Lv
- Key Laboratory of Environmental Medicine Engineering in Ministry of Education, Medical School, Southeast University, Nanjing, China
| | - Dayong Wang
- Key Laboratory of Environmental Medicine Engineering in Ministry of Education, Medical School, Southeast University, Nanjing, China
| |
Collapse
|
11
|
Schulenburg H, Félix MA. The Natural Biotic Environment of Caenorhabditis elegans. Genetics 2017; 206:55-86. [PMID: 28476862 PMCID: PMC5419493 DOI: 10.1534/genetics.116.195511] [Citation(s) in RCA: 249] [Impact Index Per Article: 35.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 02/28/2017] [Indexed: 01/05/2023] Open
Abstract
Organisms evolve in response to their natural environment. Consideration of natural ecological parameters are thus of key importance for our understanding of an organism's biology. Curiously, the natural ecology of the model species Caenorhabditis elegans has long been neglected, even though this nematode has become one of the most intensively studied models in biological research. This lack of interest changed ∼10 yr ago. Since then, an increasing number of studies have focused on the nematode's natural ecology. Yet many unknowns still remain. Here, we provide an overview of the currently available information on the natural environment of C. elegans We focus on the biotic environment, which is usually less predictable and thus can create high selective constraints that are likely to have had a strong impact on C. elegans evolution. This nematode is particularly abundant in microbe-rich environments, especially rotting plant matter such as decomposing fruits and stems. In this environment, it is part of a complex interaction network, which is particularly shaped by a species-rich microbial community. These microbes can be food, part of a beneficial gut microbiome, parasites and pathogens, and possibly competitors. C. elegans is additionally confronted with predators; it interacts with vector organisms that facilitate dispersal to new habitats, and also with competitors for similar food environments, including competitors from congeneric and also the same species. Full appreciation of this nematode's biology warrants further exploration of its natural environment and subsequent integration of this information into the well-established laboratory-based research approaches.
Collapse
Affiliation(s)
- Hinrich Schulenburg
- Zoological Institute, Christian-Albrechts Universitaet zu Kiel, 24098 Kiel, Germany
| | - Marie-Anne Félix
- Institut de Biologie de l'Ecole Normale Supérieure, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, École Normale Supérieure, L'université de Recherche Paris Sciences et Lettres, 75005, France
| |
Collapse
|
12
|
Pu YZ, Wan QL, Ding AJ, Luo HR, Wu GS. Quantitative proteomics analysis of Caenorhabditis elegans upon germ cell loss. J Proteomics 2017; 156:85-93. [DOI: 10.1016/j.jprot.2017.01.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 01/14/2017] [Accepted: 01/19/2017] [Indexed: 10/20/2022]
|
13
|
Khanna A, Kumar J, Vargas MA, Barrett L, Katewa S, Li P, McCloskey T, Sharma A, Naudé N, Nelson C, Brem R, Killilea DW, Mooney SD, Gill M, Kapahi P. A genome-wide screen of bacterial mutants that enhance dauer formation in C. elegans. Sci Rep 2016; 6:38764. [PMID: 27958277 PMCID: PMC5153853 DOI: 10.1038/srep38764] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 11/10/2016] [Indexed: 11/09/2022] Open
Abstract
Molecular pathways involved in dauer formation, an alternate larval stage that allows Caenorhabditis elegans to survive adverse environmental conditions during development, also modulate longevity and metabolism. The decision to proceed with reproductive development or undergo diapause depends on food abundance, population density, and temperature. In recent years, the chemical identities of pheromone signals that modulate dauer entry have been characterized. However, signals derived from bacteria, the major source of nutrients for C. elegans, remain poorly characterized. To systematically identify bacterial components that influence dauer formation and aging in C. elegans, we utilized the individual gene deletion mutants in E. coli (K12). We identified 56 diverse E. coli deletion mutants that enhance dauer formation in an insulin-like receptor mutant (daf-2) background. We describe the mechanism of action of a bacterial mutant cyaA, that is defective in the production of cyclic AMP, which extends lifespan and enhances dauer formation through the modulation of TGF-β (daf-7) signaling in C. elegans. Our results demonstrate the importance of bacterial components in influencing developmental decisions and lifespan in C. elegans. Furthermore, we demonstrate that C. elegans is a useful model to study bacterial-host interactions.
Collapse
Affiliation(s)
- Amit Khanna
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, USA
| | - Jitendra Kumar
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, USA
| | - Misha A Vargas
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, USA
| | - LaKisha Barrett
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, USA
| | - Subhash Katewa
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, USA
| | - Patrick Li
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, USA
| | - Tom McCloskey
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, USA
| | - Amit Sharma
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, USA
| | - Nicole Naudé
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, USA
| | | | - Rachel Brem
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, USA
| | - David W Killilea
- Nutrition &Metabolism Center, Children's Hospital Oakland Research Institute, 5700 Martin Luther King Jr. Way, Oakland, CA, USA
| | - Sean D Mooney
- Department of Biomedical Informatics and Medical Education, University of Washington, Seattle, Washington 98195, USA
| | - Matthew Gill
- Department of Metabolism &Aging, The Scripps Research Institute- Scripps Florida, Jupiter, Florida, 33458, USA
| | - Pankaj Kapahi
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, USA
| |
Collapse
|
14
|
Ertl I, Porta-de-la-Riva M, Gómez-Orte E, Rubio-Peña K, Aristizábal-Corrales D, Cornes E, Fontrodona L, Osteikoetxea X, Ayuso C, Askjaer P, Cabello J, Cerón J. Functional Interplay of Two Paralogs Encoding SWI/SNF Chromatin-Remodeling Accessory Subunits During Caenorhabditis elegans Development. Genetics 2016; 202:961-75. [PMID: 26739451 PMCID: PMC4788132 DOI: 10.1534/genetics.115.183533] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 12/21/2015] [Indexed: 12/16/2022] Open
Abstract
SWI/SNF ATP-dependent chromatin-remodeling complexes have been related to several cellular processes such as transcription, regulation of chromosomal stability, and DNA repair. The Caenorhabditis elegans gene ham-3 (also known as swsn-2.1) and its paralog swsn-2.2 encode accessory subunits of SWI/SNF complexes. Using RNA interference (RNAi) assays and diverse alleles we investigated whether ham-3 and swsn-2.2 have different functions during C. elegans development since they encode proteins that are probably mutually exclusive in a given SWI/SNF complex. We found that ham-3 and swsn-2.2 display similar functions in vulva specification, germline development, and intestinal cell proliferation, but have distinct roles in embryonic development. Accordingly, we detected functional redundancy in some developmental processes and demonstrated by RNA sequencing of RNAi-treated L4 animals that ham-3 and swsn-2.2 regulate the expression of a common subset of genes but also have specific targets. Cell lineage analyses in the embryo revealed hyper-proliferation of intestinal cells in ham-3 null mutants whereas swsn-2.2 is required for proper cell divisions. Using a proteomic approach, we identified SWSN-2.2-interacting proteins needed for early cell divisions, such as SAO-1 and ATX-2, and also nuclear envelope proteins such as MEL-28. swsn-2.2 mutants phenocopy mel-28 loss-of-function, and we observed that SWSN-2.2 and MEL-28 colocalize in mitotic and meiotic chromosomes. Moreover, we demonstrated that SWSN-2.2 is required for correct chromosome segregation and nuclear reassembly after mitosis including recruitment of MEL-28 to the nuclear periphery.
Collapse
Affiliation(s)
- Iris Ertl
- Cancer and Human Molecular Genetics, Bellvitge Biomedical Research Institute-IDIBELL, 08908 L'Hospitalet de Llobregat, Barcelona, Spain
| | - Montserrat Porta-de-la-Riva
- Cancer and Human Molecular Genetics, Bellvitge Biomedical Research Institute-IDIBELL, 08908 L'Hospitalet de Llobregat, Barcelona, Spain C. elegans Core Facility, Bellvitge Biomedical Research Institute-IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Eva Gómez-Orte
- Center for Biomedical Research of La Rioja (CIBIR), 26006 Logroño, Spain
| | - Karinna Rubio-Peña
- Cancer and Human Molecular Genetics, Bellvitge Biomedical Research Institute-IDIBELL, 08908 L'Hospitalet de Llobregat, Barcelona, Spain
| | - David Aristizábal-Corrales
- Cancer and Human Molecular Genetics, Bellvitge Biomedical Research Institute-IDIBELL, 08908 L'Hospitalet de Llobregat, Barcelona, Spain
| | - Eric Cornes
- Cancer and Human Molecular Genetics, Bellvitge Biomedical Research Institute-IDIBELL, 08908 L'Hospitalet de Llobregat, Barcelona, Spain
| | - Laura Fontrodona
- Cancer and Human Molecular Genetics, Bellvitge Biomedical Research Institute-IDIBELL, 08908 L'Hospitalet de Llobregat, Barcelona, Spain
| | - Xabier Osteikoetxea
- Cancer and Human Molecular Genetics, Bellvitge Biomedical Research Institute-IDIBELL, 08908 L'Hospitalet de Llobregat, Barcelona, Spain
| | - Cristina Ayuso
- Andalusian Center for Developmental Biology (CABD), Consejo Superior de Investigaciones Científicas/Junta de Andalucia/Universidad Pablo de Olavide, 41013 Seville, Spain
| | - Peter Askjaer
- Andalusian Center for Developmental Biology (CABD), Consejo Superior de Investigaciones Científicas/Junta de Andalucia/Universidad Pablo de Olavide, 41013 Seville, Spain
| | - Juan Cabello
- Center for Biomedical Research of La Rioja (CIBIR), 26006 Logroño, Spain
| | - Julián Cerón
- Cancer and Human Molecular Genetics, Bellvitge Biomedical Research Institute-IDIBELL, 08908 L'Hospitalet de Llobregat, Barcelona, Spain
| |
Collapse
|
15
|
Warnhoff K, Murphy JT, Kumar S, Schneider DL, Peterson M, Hsu S, Guthrie J, Robertson JD, Kornfeld K. The DAF-16 FOXO transcription factor regulates natc-1 to modulate stress resistance in Caenorhabditis elegans, linking insulin/IGF-1 signaling to protein N-terminal acetylation. PLoS Genet 2014; 10:e1004703. [PMID: 25330323 PMCID: PMC4199503 DOI: 10.1371/journal.pgen.1004703] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 08/26/2014] [Indexed: 12/24/2022] Open
Abstract
The insulin/IGF-1 signaling pathway plays a critical role in stress resistance and longevity, but the mechanisms are not fully characterized. To identify genes that mediate stress resistance, we screened for C. elegans mutants that can tolerate high levels of dietary zinc. We identified natc-1, which encodes an evolutionarily conserved subunit of the N-terminal acetyltransferase C (NAT) complex. N-terminal acetylation is a widespread modification of eukaryotic proteins; however, relatively little is known about the biological functions of NATs. We demonstrated that loss-of-function mutations in natc-1 cause resistance to a broad-spectrum of physiologic stressors, including multiple metals, heat, and oxidation. The C. elegans FOXO transcription factor DAF-16 is a critical target of the insulin/IGF-1 signaling pathway that mediates stress resistance, and DAF-16 is predicted to directly bind the natc-1 promoter. To characterize the regulation of natc-1 by DAF-16 and the function of natc-1 in insulin/IGF-1 signaling, we analyzed molecular and genetic interactions with key components of the insulin/IGF-1 pathway. natc-1 mRNA levels were repressed by DAF-16 activity, indicating natc-1 is a physiological target of DAF-16. Genetic studies suggested that natc-1 functions downstream of daf-16 to mediate stress resistance and dauer formation. Based on these findings, we hypothesize that natc-1 is directly regulated by the DAF-16 transcription factor, and natc-1 is a physiologically significant effector of the insulin/IGF-1 signaling pathway that mediates stress resistance and dauer formation. These studies identify a novel biological function for natc-1 as a modulator of stress resistance and dauer formation and define a functionally significant downstream effector of the insulin/IGF-1 signaling pathway. Protein N-terminal acetylation mediated by the NatC complex may play an evolutionarily conserved role in regulating stress resistance.
Collapse
Affiliation(s)
- Kurt Warnhoff
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - John T. Murphy
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Sandeep Kumar
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Daniel L. Schneider
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Michelle Peterson
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Simon Hsu
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - James Guthrie
- Research Reactor Center, University of Missouri, Columbia, Missouri, United States of America
| | - J. David Robertson
- Research Reactor Center, University of Missouri, Columbia, Missouri, United States of America
- Department of Chemistry, University of Missouri, Columbia, Missouri, United States of America
| | - Kerry Kornfeld
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- * E-mail:
| |
Collapse
|
16
|
Jiménez-Hidalgo M, Kurz CL, Pedrajas JR, Naranjo-Galindo FJ, González-Barrios M, Cabello J, Sáez AG, Lozano E, Button EL, Veal EA, Fierro-González JC, Swoboda P, Miranda-Vizuete A. Functional characterization of thioredoxin 3 (TRX-3), a Caenorhabditis elegans intestine-specific thioredoxin. Free Radic Biol Med 2014; 68:205-19. [PMID: 24316195 PMCID: PMC4018987 DOI: 10.1016/j.freeradbiomed.2013.11.023] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 11/13/2013] [Accepted: 11/22/2013] [Indexed: 01/15/2023]
Abstract
Thioredoxins are a class of evolutionarily conserved proteins that have been demonstrated to play a key role in many cellular processes involving redox reactions. We report here the genetic and biochemical characterization of Caenorhabditis elegans TRX-3, the first metazoan thioredoxin with an intestine-specific expression pattern. By using green fluorescent protein reporters we have found that TRX-3 is expressed in both the cytoplasm and the nucleus of intestinal cells, with a prominent localization at the apical membrane. Although intestinal function, reproductive capacity, longevity, and resistance of trx-3 loss-of-function mutants to many stresses are indistinguishable from those of wild-type animals, we have observed a slight reduction in size and a minor reduction in the defecation cycle timing of trx-3 mutants. Interestingly, trx-3 is induced upon infection by Photorhabdus luminescens and Candida albicans, and TRX-3 overexpression provides a modest protection against these pathogens. Together, our data indicate that TRX-3 function in the intestine is dispensable for C. elegans development but may be important to fight specific bacterial and fungal infections.
Collapse
Affiliation(s)
- María Jiménez-Hidalgo
- Centro Andaluz de Biología del Desarrollo, Departamento de Fisiología, Anatomía y Biología Celular, Universidad Pablo de Olavide, 41013 Sevilla, Spain
| | - Cyril Léopold Kurz
- Centre d'Immunologie de Marseille-Luminy, UM2 Aix-Marseille Université, Case 906, 13288 Marseille cedex 9, France
| | - José Rafael Pedrajas
- Grupo de Bioquímica y Señalización Celular, Departamento de Biología Experimental, Universidad de Jaén, 23071 Jaén, Spain
| | - Francisco José Naranjo-Galindo
- Centro Andaluz de Biología del Desarrollo, Departamento de Fisiología, Anatomía y Biología Celular, Universidad Pablo de Olavide, 41013 Sevilla, Spain
| | - María González-Barrios
- Centro Andaluz de Biología del Desarrollo, Departamento de Fisiología, Anatomía y Biología Celular, Universidad Pablo de Olavide, 41013 Sevilla, Spain
| | - Juan Cabello
- Center for Biomedical Research of La Rioja, 26006 Logroño, Spain
| | - Alberto G Sáez
- Unidad Funcional de Investigación en Enfermedades Crónicas, Instituto de Salud Carlos III, 28220 Majadahonda, Madrid, Spain
| | - Encarnación Lozano
- Unidad Funcional de Investigación en Enfermedades Crónicas, Instituto de Salud Carlos III, 28220 Majadahonda, Madrid, Spain
| | - Emma L Button
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Elizabeth A Veal
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Juan Carlos Fierro-González
- Center for Biosciences at Novum, Department of Biosciences and Nutrition, Karolinska Institute, S-14183 Huddinge, Sweden
| | - Peter Swoboda
- Center for Biosciences at Novum, Department of Biosciences and Nutrition, Karolinska Institute, S-14183 Huddinge, Sweden
| | - Antonio Miranda-Vizuete
- Centro Andaluz de Biología del Desarrollo, Departamento de Fisiología, Anatomía y Biología Celular, Universidad Pablo de Olavide, 41013 Sevilla, Spain; Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, 41013 Sevilla, Spain.
| |
Collapse
|
17
|
Burkholderia pseudomallei suppresses Caenorhabditis elegans immunity by specific degradation of a GATA transcription factor. Proc Natl Acad Sci U S A 2013; 110:15067-72. [PMID: 23980181 DOI: 10.1073/pnas.1311725110] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Burkholderia pseudomallei is a Gram-negative soil bacterium that infects both humans and animals. Although cell culture studies have revealed significant insights into factors contributing to virulence and host defense, the interactions between this pathogen and its intact host remain to be elucidated. To gain insights into the host defense responses to B. pseudomallei infection within an intact host, we analyzed the genome-wide transcriptome of infected Caenorhabditis elegans and identified ∼6% of the nematode genes that were significantly altered over a 12-h course of infection. An unexpected feature of the transcriptional response to B. pseudomallei was a progressive increase in the proportion of down-regulated genes, of which ELT-2 transcriptional targets were significantly enriched. ELT-2 is an intestinal GATA transcription factor with a conserved role in immune responses. We demonstrate that B. pseudomallei down-regulation of ELT-2 targets is associated with degradation of ELT-2 protein by the host ubiquitin-proteasome system. Degradation of ELT-2 requires the B. pseudomallei type III secretion system. Together, our studies using an intact host provide evidence for pathogen-mediated host immune suppression through the destruction of a host transcription factor.
Collapse
|
18
|
Fischer M, Regitz C, Kull R, Boll M, Wenzel U. Vitellogenins increase stress resistance of Caenorhabditis elegans after Photorhabdus luminescens infection depending on the steroid-signaling pathway. Microbes Infect 2013; 15:569-78. [PMID: 23727258 DOI: 10.1016/j.micinf.2013.05.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 04/23/2013] [Accepted: 05/06/2013] [Indexed: 01/07/2023]
Abstract
Resistance against environmental stress is a crucial factor in determining the lifespan of organisms. A central role herein has been recently attributed to the transport and storage of lipids with the vitellogenin family emerging as a potential key factor. Here we show that the knockdown of one out of five functional vitellogenin genes, encoding apolipoprotein B homologues, results in a reduced survival of the nematode Caenorhabditis elegans at 37 °C subsequent to infection with the bacterial pathogen Photorhabdus luminescens. An active steroid-signaling pathway, including supply of cholesterol by vitellogenins, steroid ligand formation by the cytochrome P450 dependent DAF-9, and activation of the nuclear hormone receptor DAF-12, in the presence of pathogenic bacteria was associated with reduced nuclear translocation of the forkhead transcription factor DAF-16 and increased antioxidative capacity. Taken together, the study provides functional evidence for a crucial role of vitellogenins and the steroid-signaling pathway in determination of resistance against bacteria.
Collapse
Affiliation(s)
- Malaika Fischer
- Molecular Nutrition Research, Interdisciplinary Research Center, Justus-Liebig-University of Giessen, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany
| | | | | | | | | |
Collapse
|
19
|
Goff SA, Zhang Q. Heterosis in elite hybrid rice: speculation on the genetic and biochemical mechanisms. CURRENT OPINION IN PLANT BIOLOGY 2013; 16:221-7. [PMID: 23587937 DOI: 10.1016/j.pbi.2013.03.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 03/16/2013] [Accepted: 03/18/2013] [Indexed: 05/09/2023]
Abstract
Because of the tremendous advances in functional genomics and the current availability of a large number of superior hybrids, rice is an excellent model crop system for heterosis research. Genetic dissection of yield and yield component traits of an elite rice hybrid using an ultra-high density linkage map identified overdominance as the principal genetic basis of heterosis in this hybrid. This is not an expected finding based on the reported effects of single genes. Here we propose a gene expression and protein quality control hypothesis as one possible explanation for the overdominance in hybrids bred for yield. Future studies will be directed toward the identification of the genetic and biochemical mechanisms underlying the biology of hybrid vigor.
Collapse
Affiliation(s)
- Stephen A Goff
- iPlant Collaborative, BIO5 Institute, University of Arizona, Tucson, AZ 85721, USA
| | | |
Collapse
|
20
|
Simonsen KT, Gallego SF, Færgeman NJ, Kallipolitis BH. Strength in numbers: "Omics" studies of C. elegans innate immunity. Virulence 2012; 3:477-84. [PMID: 23076279 PMCID: PMC3524146 DOI: 10.4161/viru.21906] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
For more than ten years the nematode Caenorhabditis elegans has proven to be a valuable model for studies of the host response to various bacterial and fungal pathogens. When exposed to a pathogenic organism, a clear response is elicited in the nematode, which is characterized by specific alterations on the transcriptional and translational levels. Early on, researchers took advantage of the possibility to conduct large-scale investigations of the C. elegans immune response. Multiple studies demonstrated that C. elegans does indeed mount a protective response against invading pathogens, thus rendering this small nematode a very useful and simple host model for the study of innate immunity and host-pathogen interactions. Here, we provide an overview of key aspects of innate immunity in C. elegans revealed by recent whole-genome transcriptomics and proteomics studies of the global response of C. elegans to various bacterial and fungal pathogens.
Collapse
Affiliation(s)
- Karina T Simonsen
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | | | | | | |
Collapse
|
21
|
Interaction of structure-specific and promiscuous G-protein-coupled receptors mediates small-molecule signaling in Caenorhabditis elegans. Proc Natl Acad Sci U S A 2012; 109:9917-22. [PMID: 22665789 DOI: 10.1073/pnas.1202216109] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
A chemically diverse family of small-molecule signals, the ascarosides, control developmental diapause (dauer), olfactory learning, and social behaviors of the nematode model organism, Caenorhabditis elegans. The ascarosides act upstream of conserved signaling pathways, including the insulin, TGF-β, serotonin, and guanylyl cyclase pathways; however, the sensory processes underlying ascaroside function are poorly understood. Because ascarosides often are multifunctional and show strongly synergistic effects, characterization of their receptors will be essential for understanding ascaroside biology and may provide insight into molecular mechanisms that produce synergistic outcomes in small-molecule sensing. Based on DAF-8 immunoprecipitation, we here identify two G-protein-coupled receptors, DAF-37 and DAF-38, which cooperatively mediate ascaroside perception. daf-37 mutants are defective in all responses to ascr#2, one of the most potent dauer-inducing ascarosides, although this mutant responds normally to other ascarosides. In contrast, daf-38 mutants are partially defective in responses to several different ascarosides. Through cell-specific overexpression, we show that DAF-37 regulates dauer when expressed in ASI neurons and adult behavior when expressed in ASK neurons. Using a photoaffinity-labeled ascr#2 probe and amplified luminescence assays (AlphaScreen), we demonstrate that ascr#2 binds to DAF-37. Photobleaching fluorescent energy transfer assays revealed that DAF-37 and DAF-38 form heterodimers, and we show that heterodimerization strongly increases cAMP inhibition in response to ascr#2. These results suggest that that the ascarosides' intricate signaling properties result in part from the interaction of highly structure-specific G-protein-coupled receptors such as DAF-37 with more promiscuous G-protein-coupled receptors such as DAF-38.
Collapse
|
22
|
Boehnisch C, Wong D, Habig M, Isermann K, Michiels NK, Roeder T, May RC, Schulenburg H. Protist-type lysozymes of the nematode Caenorhabditis elegans contribute to resistance against pathogenic Bacillus thuringiensis. PLoS One 2011; 6:e24619. [PMID: 21931778 PMCID: PMC3169628 DOI: 10.1371/journal.pone.0024619] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Accepted: 08/14/2011] [Indexed: 11/18/2022] Open
Abstract
Pathogens represent a universal threat to other living organisms. Most organisms express antimicrobial proteins and peptides, such as lysozymes, as a protection against these challenges. The nematode Caenorhabditis elegans harbours 15 phylogenetically diverse lysozyme genes, belonging to two distinct types, the protist- or Entamoeba-type (lys genes) and the invertebrate-type (ilys genes) lysozymes. In the present study we characterized the role of several protist-type lysozyme genes in defence against a nematocidal strain of the Gram-positive bacterium Bacillus thuringiensis. Based on microarray and subsequent qRT-PCR gene expression analysis, we identified protist-type lysozyme genes as one of the differentially transcribed gene classes after infection. A functional genetic analysis was performed for three of these genes, each belonging to a distinct evolutionary lineage within the protist-type lysozymes (lys-2, lys-5, and lys-7). Their knock-out led to decreased pathogen resistance in all three cases, while an increase in resistance was observed when two out of three tested genes were overexpressed in transgenic lines (lys-5, lys-7, but not lys-2). We conclude that the lysozyme genes lys-5, lys-7, and possibly lys-2 contribute to resistance against B. thuringiensis, thus highlighting the particular role of lysozymes in the nematode's defence against pathogens.
Collapse
Affiliation(s)
- Claudia Boehnisch
- Institute for Evolution and Biodiversity, University of Muenster, Muenster, Germany
- Department of Animal Evolutionary Ecology, University of Tuebingen, Tuebingen, Germany
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Daniel Wong
- Centre d'Immunologie de Marseille-Luminy, Université de la Méditerranée, Marseille, France
- INSERM, Marseille, France
- CNRS, Marseille, France
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Michael Habig
- Department of Evolutionary Ecology and Genetics, University of Kiel, Kiel, Germany
| | | | - Nicolaas K. Michiels
- Institute for Evolution and Biodiversity, University of Muenster, Muenster, Germany
- Department of Animal Evolutionary Ecology, University of Tuebingen, Tuebingen, Germany
| | - Thomas Roeder
- Department of Zoophysiology, University of Kiel, Kiel, Germany
| | - Robin C. May
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Hinrich Schulenburg
- Institute for Evolution and Biodiversity, University of Muenster, Muenster, Germany
- Department of Animal Evolutionary Ecology, University of Tuebingen, Tuebingen, Germany
- Department of Evolutionary Ecology and Genetics, University of Kiel, Kiel, Germany
| |
Collapse
|