scholarly journals Caenorhabditis elegans processes sensory information to choose between freeloading and self-defense strategies

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Jodie A Schiffer ◽  
Francesco A Servello ◽  
William R Heath ◽  
Francis Raj Gandhi Amrit ◽  
Stephanie V Stumbur ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Caenorhabditis Elegans ◽  
Sensory Information ◽  
Local Environment ◽  
Adaptive Strategy ◽  
Chemical Weapon ◽  
Nematode Caenorhabditis Elegans ◽  
Defense Strategies ◽  
E Coli ◽  
Self Defense

Hydrogen peroxide is the preeminent chemical weapon that organisms use for combat. Individual cells rely on conserved defenses to prevent and repair peroxide-induced damage, but whether similar defenses might be coordinated across cells in animals remains poorly understood. Here, we identify a neuronal circuit in the nematode Caenorhabditis elegans that processes information perceived by two sensory neurons to control the induction of hydrogen peroxide defenses in the organism. We found that catalases produced by Escherichia coli, the nematode’s food source, can deplete hydrogen peroxide from the local environment and thereby protect the nematodes. In the presence of E. coli, the nematode’s neurons signal via TGFβ-insulin/IGF1 relay to target tissues to repress expression of catalases and other hydrogen peroxide defenses. This adaptive strategy is the first example of a multicellular organism modulating its defenses when it expects to freeload from the protection provided by molecularly orthologous defenses from another species.

scholarly journals Caenorhabditis elegans processes sensory information to choose between freeloading and self-defense strategies

2020 ◽  
Author(s):  
Jodie Schiffer ◽  
Francesco Servello ◽  
William Heath ◽  
Francis Raj Gandhi Amrit ◽  
Stephanie Stumbur ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Caenorhabditis Elegans ◽  
Sensory Neurons ◽  
Sensory Information ◽  
Local Environment ◽  
Adaptive Strategy ◽  
Chemical Weapon ◽  
Defense Strategies ◽  
E Coli ◽  
Self Defense

AbstractHydrogen peroxide is the preeminent chemical weapon that organisms use for combat. Individual cells rely on conserved defenses to prevent and repair peroxide-induced damage, but whether similar defenses might be coordinated across cells in animals remains poorly understood. Here, we identify a neuronal circuit in the nematode Caenorhabditis elegans that processes information perceived by two sensory neurons to control the induction of hydrogen-peroxide defenses in the organism. We found that catalases produced by Escherichia coli, the nematode’s food source, can deplete hydrogen peroxide from the local environment and thereby protect the nematodes. In the presence of E. coli, the nematode’s neurons signal via TGFβ-insulin/IGF1 relay to target tissues to repress expression of catalases and other hydrogen-peroxide defenses. This adaptive strategy is the first example of a multicellular organism modulating its defenses when it expects to freeload from the protection provided by molecularly orthologous defenses from another species.

scholarly journals Author response: Caenorhabditis elegans processes sensory information to choose between freeloading and self-defense strategies

2020 ◽  
Author(s):  
Jodie A Schiffer ◽  
Francesco A Servello ◽  
William R Heath ◽  
Francis Raj Gandhi Amrit ◽  
Stephanie V Stumbur ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Sensory Information ◽  
Author Response ◽  
Defense Strategies ◽  
Self Defense

scholarly journals THE DNA OF CAENORHABDITIS ELEGANS

Genetics ◽  
1974 ◽  
Vol 77 (1) ◽  
pp. 95-104
Author(s):  
J E Sulston ◽  
S Brenner
Keyword(s):  
Caenorhabditis Elegans ◽  
Chemical Analysis ◽  
Dna Sequences ◽  
Base Composition ◽  
Nematode Caenorhabditis Elegans ◽  
5S Rna ◽  
Base Pairs ◽  
Small Component ◽  
E Coli ◽  
The Mean

ABSTRACT Chemical analysis and a study of renaturation kinetics show that the nematode, Caenorhabditis elegans, has a haploid DNA content of 8 x IO7 base pairs (20 times the genome of E. coli). Eighty-three percent of the DNA sequences are unique. The mean base composition is 36% GC; a small component, containing the rRNA cistrons, has a base composition of 51% GC. The haploid genome contains about 300 genes for 4s RNA, 110 for 5s RNA, and 55 for (18 + 28)S RNA.

scholarly journals Superoxide dismutase 1 (SOD1) and cadmium: a three models approach to the comprehension of its neurotoxic effects

2021 ◽  
Vol 4 (s1) ◽  
Author(s):  
Federica Bovio ◽  
Barbara Sciandrone ◽  
Chiara Urani ◽  
Paola Fusi ◽  
Matilde Forcella ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Caenorhabditis Elegans ◽  
Recombinant Protein ◽  
Neuronal Cells ◽  
Expression Level ◽  
Superoxide Dismutase 1 ◽  
Biological Models ◽  
Nematode Caenorhabditis Elegans ◽  
E Coli ◽  
Neurotoxic Effects

In three different biological models, the recombinant protein expressed in E. coli, the neuronal cells SH-SY5Y and the nematode Caenorhabditis elegans, cadmium inhibits SOD1 activity without affecting its expression level.

scholarly journals SPECTROPHOTOMETRIC METHOD TO ESTIMATE GLYCOGEN LEVELS IN THE MODEL NEMATODE CAENORHABDITIS ELEGANS

2020 ◽  
pp. 383-387
Author(s):  
Sidor ◽  
Andreyanov
Keyword(s):  
Caenorhabditis Elegans ◽  
Spectrophotometric Method ◽  
Cell Biology ◽  
Metabolic Regulation ◽  
Enzyme Analysis ◽  
Nematode Caenorhabditis Elegans ◽  
E Coli ◽  
C Elegans ◽  
Energy Maintenance

The model nematode Caenorhabditis elegans is widely used in studies on metabolic regulation and aging processes, in developmental and cell biology, neurobiology and genetics. Recent studies have shown the crucial role of glycogen, the glucose polymer, in stress resistance, energy maintenance and aging of organisms. Currently, the main methods for determining glycogen in the C. elegans nematode are iodine staining, enzyme analysis, and Raman microspectroscopy, described in 2019 by A. Cherkas. The proposed spectrophotometric method allows us to quantify glycogen levels, in contrast to those used in modern practice. The nematode was grown on NGM agar seeded with E. coli as a food source for 7 days in a thermostat at 20±20 C. Then, it was washed with M9 buffer and separated from bacteria by centrifugation for 10 min at 9 000 g. The samples were placed in an ice bath and nematodes were counted in each sample at x 10 microscope magnification. The glycogen concentration was determined spectrophotometrically. This value is average for different stages of the nematode development and amounts to 0.001821 ± 0.000009 μg.

Effectiveness of Cleaners and Sanitizers in Killing Salmonella Newport in the Gut of a Free-Living Nematode, Caenorhabditis elegans

2004 ◽  
Vol 67 (10) ◽  
pp. 2151-2157 ◽  
Author(s):  
STEPHEN J. KENNEY ◽  
GARY L. ANDERSON ◽  
PHILLIP L. WILLIAMS ◽  
PATRICIA D. MILLNER ◽  
LARRY R. BEUCHAT
Keyword(s):  
Caenorhabditis Elegans ◽  
Relative Humidity ◽  
Nalidixic Acid ◽  
Fruits And Vegetables ◽  
Nematode Caenorhabditis Elegans ◽  
Free Living ◽  
E Coli ◽  
C Elegans ◽  
Salmonella Newport ◽  
Free Living Nematode

Caenorhabditis elegans, a free-living nematode found in soil, has been shown to ingest human enteric pathogens, thereby potentially serving as a vector for preharvest contamination of fruits and vegetables. A study was undertaken to evaluate the efficacy of cleaners and sanitizers in killing Salmonella enterica serotype Newport in the gut of C. elegans. Adult worms were fed nalidixic acid–adapted cells of Escherichia coli OP50 (control) or Salmonella Newport for 24 h, washed, placed on paper discs, and incubated at temperatures of 4 or 20°C and relative humidities of 33 or 98% for 24 h. Two commercial cleaners (Enforce and K Foam Lo) and four sanitizers (2% acetic acid, 2% lactic acid, Sanova, and chlorine [50 and 200 μg/ml]) were applied to worms for 0, 2, or 10 min. Populations of E. coli and Salmonella Newport (CFU per worm) in untreated and treated worms were determined by sonicating worms in 0.1% peptone and surface plating suspensions of released cells on tryptic soy agar containing nalidixic acid. Populations of Salmonella Newport in worms exposed to 33 or 98% relative humidity at 4°C or 33% relative humidity at 20°C were significantly (P ≤ 0.05) lower than the number surviving exposure to 98% relative humidity at 20°C. In general, treatment of desiccated worms with cleaners and sanitizers was effective in significantly (P ≤ 0.05) reducing the number of ingested Salmonella Newport. Results indicate that temperature and relative humidity influence the survival of Salmonella Newport in the gut of C. elegans, and cleaners and sanitizers may not eliminate the pathogen.

The Effect of Mianserin on Lifespan of Caenorhabditis elegans is Abolished by Glucose

2021 ◽  
Vol 13 ◽  
Author(s):  
Abdullah Almotayri ◽  
Jency Thomas ◽  
Mihiri Munasinghe ◽  
Markandeya Jois
Keyword(s):  
Caenorhabditis Elegans ◽  
Scaffolding Protein ◽  
Lifespan Extension ◽  
Wild Type ◽  
E Coli ◽  
C Elegans ◽  
Risk Of Death ◽  
Increased Risk ◽  
Antidepressant Use ◽  
Extension Effect

Background: The antidepressant mianserin has been shown to extend the lifespan of Caenorhabditis elegans (C. elegans), a well-established model organism used in aging research. The extension of lifespan in C. elegans was shown to be dependent on increased expression of the scaffolding protein (ANK3/unc-44). In contrast, antidepressant use in humans is associated with an increased risk of death. The C. elegans in the laboratory are fed Escherichia coli (E. coli), a diet high in protein and low in carbohydrate, whereas a typical human diet is high in carbohydrates. We hypothesized that dietary carbohydrates might mitigate the lifespan-extension effect of mianserin. Objective: To investigate the effect of glucose added to the diet of C. elegans on the lifespan-extension effect of mianserin. Methods: Wild-type Bristol N2 and ANK3/unc-44 inactivating mutants were cultured on agar plates containing nematode growth medium and fed E. coli. Treatment groups included (C) control, (M50) 50 μM mianserin, (G) 73 mM glucose, and (M50G) 50 μM mianserin and 73 mM glucose. Lifespan was determined by monitoring the worms until they died. Statistical analysis was performed using the Kaplan-Meier version of the log-rank test. Results: Mianserin treatment resulted in a 12% increase in lifespan (P<0.05) of wild-type Bristol N2 worms but reduced lifespan by 6% in ANK3/unc-44 mutants, consistent with previous research. The addition of glucose to the diet reduced the lifespan of both strains of worms and abolished the lifespan-extension by mianserin. Conclusion: The addition of glucose to the diet of C. elegans abolishes the lifespan-extension effects of mianserin.

Interaction of a Free-Living Soil Nematode, Caenorhabditis elegans, with Surrogates of Foodborne Pathogenic Bacteria

2003 ◽  
Vol 66 (9) ◽  
pp. 1543-1549 ◽  
Author(s):  
GARY L. ANDERSON ◽  
KRISHAUN N. CALDWELL ◽  
LARRY R. BEUCHAT ◽  
PHILLIP L. WILLIAMS
Keyword(s):  
Caenorhabditis Elegans ◽  
Young Adult ◽  
Salmonella Typhimurium ◽  
Avirulent Strain ◽  
Soil Nematode ◽  
Gram Negative Bacteria ◽  
Nematode Caenorhabditis Elegans ◽  
Free Living ◽  
Gram Positive ◽  
Gram Negative

Free-living nematodes may harbor, protect, and disperse bacteria, including those ingested and passed in viable form in feces. These nematodes are potential vectors for human pathogens and may play a role in foodborne diseases associated with fruits and vegetables eaten raw. In this study, we evaluated the associations between a free-living soil nematode, Caenorhabditis elegans, and Escherichia coli, an avirulent strain of Salmonella Typhimurium, Listeria welshimeri, and Bacillus cereus. On an agar medium, young adult worms quickly moved toward colonies of all four bacteria; over 90% of 3-day-old adult worms entered colonies within 16 min after inoculation. After 48 h, worms moved in and out of colonies of L. welshimeri and B. cereus but remained associated with E. coli and Salmonella Typhimurium colonies for at least 96 h. Young adult worms fed on cells of the four bacteria suspended in K medium. Worms survived and reproduced with the use of nutrients derived from all test bacteria, as determined for eggs laid by second-generation worms after culturing for 96 h. Development was slightly slower for worms fed gram-positive bacteria than for worms fed gram-negative bacteria. Worms that fed for 24 h on bacterial lawns formed on tryptic soy agar dispersed bacteria over a 3-h period when they were transferred to a bacteria-free agar surface. The results of this study suggest that C. elegans and perhaps other free-living nematodes are potential vectors for both gram-positive and gram-negative bacteria, including foodborne pathogens in soil.

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