Phytobacter diazotrophicus from Intestine of Caenorhabditis elegans Confers Colonization-Resistance against Bacillus nematocida Using Flagellin (FliC) as an Inhibition Factor

Symbiotic microorganisms in the intestinal tract can influence the general fitness of their hosts and contribute to protecting them against invading pathogens. In this study, we obtained isolate Phytobacter diazotrophicus SCO41 from the gut of free-living nematode Caenorhabditis elegans that displayed strong colonization-resistance against invading biocontrol bacterium Bacillus nematocida B16. The colonization-resistance phenotype was found to be mediated by a 37-kDa extracellular protein that was identified as flagellin (FliC). With the help of genome information, the fliC gene was cloned and heterologously expressed in E. coli. It could be shown that the B. nematocida B16 grows in chains rather than in planktonic form in the presence of FliC. Scanning Electronic Microscopy results showed that protein FliC-treated B16 bacterial cells are thinner and longer than normal cells. Localization experiments confirmed that the protein FliC is localized in both the cytoplasm and the cell membrane of B16 strain, in the latter especially at the position of cell division. ZDOCK analysis showed that FliC could bind with serine/threonine protein kinase, membrane protein insertase YidC and redox membrane protein CydB. It was inferred that FliC interferes with cell division of B. nematocidal B16, therefore inhibiting its colonization of C. elegans intestines in vivo. The isolation of P. diazotrophicus as part of the gut microbiome of C. elegans not only provides interesting insights about the lifestyle of this nitrogen-fixing bacterium, but also reveals how the composition of the natural gut microbiota of nematodes can affect biological control efforts by protecting the host from its natural enemies.

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Proteolysis in Caenorhabditis elegans sex determination: cleavage of TRA-2A by TRA-3

Genes & Development ◽

10.1101/gad.14.8.901 ◽

2000 ◽

Vol 14 (8) ◽

pp. 901-906

Author(s):

Sharon B. Sokol ◽

Patricia E. Kuwabara

Keyword(s):

Caenorhabditis Elegans ◽

Membrane Protein ◽

Cell Fate ◽

Calcium Binding ◽

Female Development ◽

C Elegans ◽

Calcium Dependent ◽

Substrate Cleavage ◽

Ef Hands

The Caenorhabditis elegans tra-3 gene promotes female development in XX hermaphrodites and encodes an atypical calpain regulatory protease lacking calcium-binding EF hands. We report that despite the absence of EF hands, TRA-3 has calcium-dependent proteolytic activity and its proteolytic domain is essential for in vivo function. We show that the membrane protein TRA-2A, which promotes XX female development by repressing the masculinizing protein FEM-3, is a TRA-3 substrate. Cleavage of TRA-2A by TRA-3 generates a peptide predicted to have feminizing activity. These results indicate that proteolysis regulated by calcium may control some aspects of sexual cell fate in C. elegans.

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Caenorhabditis elegans as an in vivo Model to Assess Amphetamine Tolerance

Brain Behavior and Evolution ◽

10.1159/000514858 ◽

2021 ◽

pp. 1-9

Author(s):

Dayana Torres Valladares ◽

Sirisha Kudumala ◽

Murad Hossain ◽

Lucia Carvelli

Keyword(s):

Caenorhabditis Elegans ◽

Molecular Mechanisms ◽

Drugs Of Abuse ◽

Genetic Model ◽

In Vivo Model ◽

C Elegans ◽

Hyperactivity Disorder ◽

In Vitro Data

Amphetamine is a potent psychostimulant also used to treat attention deficit/hyperactivity disorder and narcolepsy. In vivo and in vitro data have demonstrated that amphetamine increases the amount of extra synaptic dopamine by both inhibiting reuptake and promoting efflux of dopamine through the dopamine transporter. Previous studies have shown that chronic use of amphetamine causes tolerance to the drug. Thus, since the molecular mechanisms underlying tolerance to amphetamine are still unknown, an animal model to identify the neurochemical mechanisms associated with drug tolerance is greatly needed. Here we took advantage of a unique behavior caused by amphetamine in <i>Caenorhabditis elegans</i> to investigate whether this simple, but powerful, genetic model develops tolerance following repeated exposure to amphetamine. We found that at least 3 treatments with 0.5 mM amphetamine were necessary to see a reduction in the amphetamine-induced behavior and, thus, to promote tolerance. Moreover, we found that, after intervals of 60/90 minutes between treatments, animals were more likely to exhibit tolerance than animals that underwent 10-minute intervals between treatments. Taken together, our results show that <i>C. elegans</i> is a suitable system to study tolerance to drugs of abuse such as amphetamines.

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Transfer and tissue-specific accumulation of components in embryos of Caenorhabditis elegans and dolichura: in vivo analysis with a low-cost signal

Development ◽

10.1242/dev.114.2.317 ◽

1992 ◽

Vol 114 (2) ◽

pp. 317-330 ◽

Cited By ~ 4

Author(s):

O. Bossinger ◽

E. Schierenberg

Keyword(s):

Caenorhabditis Elegans ◽

Low Cost ◽

Free Living ◽

Tissue Specific ◽

C Elegans ◽

Specific Accumulation ◽

In Vivo Analysis

The pattern of autofluorescence in the two free-living namatodes Rhabditis dolichura and Caenorhabditis compared. In C. elegans, during later embryogenesis cells develop a typical bluish autofluorescence as illumination, while in Rh. dolichura a strong already present in the unfertilized egg. Using a new,

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Haematophagic Caenorhabditis elegans

Parasitology ◽

10.1017/s0031182018001518 ◽

2018 ◽

Vol 146 (3) ◽

pp. 314-320 ◽

Cited By ~ 1

Author(s):

Veeren M Chauhan ◽

David I Pritchard

Keyword(s):

Caenorhabditis Elegans ◽

Neutralizing Antibodies ◽

Fluorescent Microscopy ◽

Free Living ◽

C Elegans ◽

Vaccine Responses ◽

Nematode Parasites ◽

Significant Difference ◽

Free Living Nematode ◽

Bright Emission

AbstractCaenorhabditis elegans is a free-living nematode that resides in soil and typically feeds on bacteria. We postulate that haematophagic C. elegans could provide a model to evaluate vaccine responses to intestinal proteins from hematophagous nematode parasites, such as Necator americanus. Human erythrocytes, fluorescently labelled with tetramethylrhodamine succinimidyl ester, demonstrated a stable bright emission and facilitated visualization of feeding events with fluorescent microscopy. C. elegans were observed feeding on erythrocytes and were shown to rupture red blood cells upon capture to release and ingest their contents. In addition, C. elegans survived equally on a diet of erythrocytes. There was no statistically significant difference in survival when compared with a diet of Escherichia coli OP50. The enzymes responsible for the digestion and detoxification of haem and haemoglobin, which are key components of the hookworm vaccine, were found in the C. elegans intestine. These findings support our postulate that free-living nematodes could provide a model for the assessment of neutralizing antibodies to current and future hematophagous parasite vaccine candidates.

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Edible Flowers of Tagetes erecta L. as Functional Ingredients: Phenolic Composition, Antioxidant and Protective Effects on Caenorhabditis elegans

Nutrients ◽

10.3390/nu10122002 ◽

2018 ◽

Vol 10 (12) ◽

pp. 2002 ◽

Cited By ~ 7

Author(s):

Cristina Moliner ◽

Lillian Barros ◽

Maria Dias ◽

Víctor López ◽

Elisa Langa ◽

...

Keyword(s):

Caenorhabditis Elegans ◽

In Vivo Model ◽

Tagetes Erecta ◽

Protective Effects ◽

Phenolic Composition ◽

C Elegans ◽

Amyloid Toxicity ◽

Phenolic Profiles ◽

Tagetes Erecta L

Tagetes erecta L. has long been consumed for culinary and medicinal purposes in different countries. The aim of this study was to explore the potential benefits from two cultivars of T. erecta related to its polyphenolic profile as well as antioxidant and anti-aging properties. The phenolic composition was analyzed by LC-DAD-ESI/MSn. Folin-Ciocalteu, DPPH·, and FRAP assays were performed in order to evaluate reducing antiradical properties. The neuroprotective potential was evaluated using the enzymes acetylcholinesterase and monoamine oxidase. Caenorhabditis elegans was used as an in vivo model to assess extract toxicity, antioxidant activity, delayed aging, and reduced β-amyloid toxicity. Both extracts showed similar phenolic profiles and bioactivities. The main polyphenols found were laricitin and its glycosides. No acute toxicity was detected for extracts in the C. elegans model. T. erecta flower extracts showed promising antioxidant and neuroprotective properties in the different tested models. Hence, these results may add some information supporting the possibilities of using these plants as functional foods and/or as nutraceutical ingredients.

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Identification of gmhA, a Yersinia pestis Gene Required for Flea Blockage, by Using a Caenorhabditis elegans Biofilm System

Infection and Immunity ◽

10.1128/iai.73.11.7236-7242.2005 ◽

2005 ◽

Vol 73 (11) ◽

pp. 7236-7242 ◽

Cited By ~ 55

Author(s):

Creg Darby ◽

Sandya L. Ananth ◽

Li Tan ◽

B. Joseph Hinnebusch

Keyword(s):

Caenorhabditis Elegans ◽

Yersinia Pestis ◽

Biofilm Formation ◽

Yersinia Pseudotuberculosis ◽

C Elegans ◽

Transposon Insertion ◽

Insertion Mutants ◽

Random Screening

ABSTRACT Yersinia pestis, the cause of bubonic plague, blocks feeding by its vector, the flea. Recent evidence indicates that blockage is mediated by an in vivo biofilm. Y. pestis and the closely related Yersinia pseudotuberculosis also make biofilms on the cuticle of the nematode Caenorhabditis elegans, which block this laboratory animal's feeding. Random screening of Y. pseudotuberculosis transposon insertion mutants with a C. elegans biofilm assay identified gmhA as a gene required for normal biofilms. gmhA encodes phosphoheptose isomerase, an enzyme required for synthesis of heptose, a conserved component of lipopolysaccharide and lipooligosaccharide. A Y. pestis gmhA mutant was constructed and was severely defective for C. elegans biofilm formation and for flea blockage but only moderately defective in an in vitro biofilm assay. These results validate use of the C. elegans biofilm system to identify genes and pathways involved in Y. pestis flea blockage.

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In the Model Host Caenorhabditis elegans, Sphingosine-1-Phosphate-Mediated Signaling Increases Immunity toward Human Opportunistic Bacteria

International Journal of Molecular Sciences ◽

10.3390/ijms21217813 ◽

2020 ◽

Vol 21 (21) ◽

pp. 7813

Author(s):

Kiho Lee ◽

Iliana Escobar ◽

Yeeun Jang ◽

Wooseong Kim ◽

Frederick M. Ausubel ◽

...

Keyword(s):

Caenorhabditis Elegans ◽

Stress Responses ◽

Mapk Signaling ◽

Dependent Manner ◽

Cellular Functions ◽

Kinase Gene ◽

Concentration Dependent Manner ◽

C Elegans ◽

Opportunistic Bacteria ◽

Free Living Nematode

Sphingosine-1-phophate (S1P) is a sphingolipid-derived signaling molecule that controls diverse cellular functions including cell growth, homeostasis, and stress responses. In a variety of metazoans, cytosolic S1P is transported into the extracellular space where it activates S1P receptors in a concentration-dependent manner. In the free-living nematode Caenorhabditis elegans, the spin-2 gene, which encodes a S1P transporter, is activated during Gram-positive or Gram-negative bacterial infection of the intestine. However, the role during infection of spin-2 and three additional genes in the C. elegans genome encoding other putative S1P transporters has not been elucidated. Here, we report an evolutionally conserved function for S1P and a non-canonical role for S1P transporters in the C. elegans immune response to bacterial pathogens. We found that mutations in the sphingosine kinase gene (sphk-1) or in the S1P transporter genes spin-2 or spin-3 decreased nematode survival after infection with Pseudomonas aeruginosa or Enterococcus faecalis. In contrast to spin-2 and spin-3, mutating spin-1 leads to an increase in resistance to P. aeruginosa. Consistent with these results, when wild-type C. elegans were supplemented with extracellular S1P, we found an increase in their lifespan when challenged with P. aeruginosa and E. faecalis. In comparison, spin-2 and spin-3 mutations suppressed the ability of S1P to rescue the worms from pathogen-mediated killing, whereas the spin-1 mutation had no effect on the immune-enhancing activity of S1P. S1P demonstrated no antimicrobial activity toward P. aeruginosa and Escherichia coli and only minimal activity against E. faecalis MMH594 (40 µM). These data suggest that spin-2 and spin-3, on the one hand, and spin-1, on the other hand, transport S1P across cellular membranes in opposite directions. Finally, the immune modulatory effect of S1P was diminished in C. eleganssek-1 and pmk-1 mutants, suggesting that the immunomodulatory effects of S1P are mediated by the p38 MAPK signaling pathway.

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Rosemary Flowers as Edible Plant Foods: Phenolic Composition and Antioxidant Properties in Caenorhabditis elegans

Antioxidants ◽

10.3390/antiox9090811 ◽

2020 ◽

Vol 9 (9) ◽

pp. 811

Author(s):

Cristina Moliner ◽

Víctor López ◽

Lillian Barros ◽

Maria Inês Dias ◽

Isabel C. F. R. Ferreira ◽

...

Keyword(s):

Caenorhabditis Elegans ◽

Antioxidant Properties ◽

Ethanolic Extract ◽

Food Ingredient ◽

Edible Plant ◽

Phenolic Profile ◽

C Elegans ◽

Rosmarinus Officinalis L

Rosmarinus officinalis L., commonly known as rosemary, has been largely studied for its wide use as food ingredient and medicinal plant; less attention has been given to its edible flowers, being necessary to evaluate their potential as functional foods or nutraceuticals. To achieve that, the phenolic profile of the ethanolic extract of R. officinalis flowers was determined using LC-DAD-ESI/MSn and then its antioxidant and anti-ageing potential was studied through in vitro and in vivo assays using Caenorhabditis elegans. The phenolic content was 14.3 ± 0.1 mg/g extract, trans rosmarinic acid being the predominant compound in the extract, which also exhibited a strong antioxidant capacity in vitro and increased the survival rate of C. elegans exposed to lethal oxidative stress. Moreover, R. officinalis flowers extended C. elegans lifespan up to 18%. Therefore, these findings support the potential use of R. officinalis flowers as ingredients to develop products with pharmaceutical and/or nutraceutical potential.

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In vivo analysis of FANCD2 recruitment at meiotic DNA breaks in Caenorhabditis elegans

Scientific Reports ◽

10.1038/s41598-019-57096-1 ◽

2020 ◽

Vol 10 (1) ◽

Cited By ~ 2

Author(s):

Marcello Germoglio ◽

Anna Valenti ◽

Ines Gallo ◽

Chiara Forenza ◽

Pamela Santonicola ◽

...

Keyword(s):

Dna Repair ◽

Caenorhabditis Elegans ◽

Genome Stability ◽

Genetic Interaction ◽

Model Systems ◽

Dna Breaks ◽

Strand Breaks ◽

C Elegans ◽

In Vivo Analysis

AbstractFanconi Anemia is a rare genetic disease associated with DNA repair defects, congenital abnormalities and infertility. Most of FA pathway is evolutionary conserved, allowing dissection and mechanistic studies in simpler model systems such as Caenorhabditis elegans. In the present study, we employed C. elegans to better understand the role of FA group D2 (FANCD2) protein in vivo, a key player in promoting genome stability. We report that localization of FCD-2/FANCD2 is dynamic during meiotic prophase I and requires its heterodimeric partner FNCI-1/FANCI. Strikingly, we found that FCD-2 recruitment depends on SPO-11-induced double-strand breaks (DSBs) but not RAD-51-mediated strand invasion. Furthermore, exposure to DNA damage-inducing agents boosts FCD-2 recruitment on the chromatin. Finally, analysis of genetic interaction between FCD-2 and BRC-1 (the C. elegans orthologue of mammalian BRCA1) supports a role for these proteins in different DSB repair pathways. Collectively, we showed a direct involvement of FCD-2 at DSBs and speculate on its function in driving meiotic DNA repair.

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A functional study of all 40 Caenorhabditis elegans insulin-like peptides

Journal of Biological Chemistry ◽

10.1074/jbc.ra118.004542 ◽

2018 ◽

Vol 293 (43) ◽

pp. 16912-16922 ◽

Cited By ~ 20

Author(s):

Shanqing Zheng ◽

Hilton Chiu ◽

Jeffrey Boudreau ◽

Tony Papanicolaou ◽

William Bendena ◽

...

Keyword(s):

Caenorhabditis Elegans ◽

Life Span ◽

Peptide Ligands ◽

Peptide Sequence ◽

Functional Study ◽

C Elegans ◽

Multiple Phenotypes ◽

Dauer Formation ◽

Pleiotropic Function

The human genome encodes 10 insulin-like genes, whereas the Caenorhabditis elegans genome remarkably encodes 40 insulin-like genes. Knockout strategies to determine the roles of all the insulin/insulin-like peptide ligands (INS) in C. elegans has been challenging due to functional redundancy. Here, we individually overexpressed each of the 40 ins genes pan-neuronally, and monitored multiple phenotypes including: L1 arrest life span, neuroblast divisions under L1 arrest, dauer formation, and fat accumulation, as readouts to characterize the functions of each INS in vivo. Of the 40 INS peptides, we found functions for 35 INS peptides and functionally categorized each as agonists, antagonists, or of pleiotropic function. In particular, we found that 9 of 16 agonistic INS peptides shortened L1 arrest life span and promoted neuroblast divisions during L1 arrest. Our study revealed that a subset of β-class INS peptides that contain a distinct F peptide sequence are agonists. Our work is the first to categorize the structures of INS peptides and relate these structures to the functions of all 40 INS peptides in vivo. Our findings will promote the study of insulin function on development, metabolism, and aging-related diseases.

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