Food bacteria and synthetic microparticles of similar size influence pharyngeal pumping of Caenorhabditis elegans

2021 ◽  
pp. 105827
Author(s):  
Hendrik Fueser ◽  
Marie-Theres Rauchschwalbe ◽  
Sebastian Höss ◽  
Walter Traunspurger
2004 ◽  
Vol 91 (5) ◽  
pp. 1104-1115 ◽  
Author(s):  
Elizabeth Rex ◽  
Scott C. Molitor ◽  
Vera Hapiak ◽  
Hong Xiao ◽  
Megan Henderson ◽  
...  

Genetics ◽  
1995 ◽  
Vol 141 (4) ◽  
pp. 1365-1382 ◽  
Author(s):  
D M Raizen ◽  
R Y Lee ◽  
L Avery

Abstract We studied the control of pharyngeal excitation in Caenorhabditis elegans. By laser ablating subsets of the pharyngeal nervous system, we found that the MC neuron type is necessary and probably sufficient for rapid pharyngeal pumping. Electropharyngeograms showed that MC transmits excitatory postsynaptic potentials, suggesting that MC acts as a neurogenic pacemaker for pharyngeal pumping. Mutations in genes required for acetylcholine (ACh) release and an antagonist of the nicotinic ACh receptor (nAChR) reduced pumping rates, suggesting that a nAChR is required for MC transmission. To identify genes required for MC neurotransmission, we screened for mutations that cause slow pumping but no other defects. Mutations in two genes, eat-2 and eat-18, eliminated MC neurotransmission. A gain-of-function eat-18 mutation, ad820sd, and a putative loss-of-function eat-18 mutation, ad1110, both reduced the excitation of pharyngeal muscle in response to the nAChR agonists nicotine and carbachol, suggesting that eat-18 is required for the function of a pharyngeal nAChR. Fourteen recessive mutations in eat-2 fell into five complementation classes. We found allele-specific genetic interactions between eat-2 and eat-18 that correlated with complementation classes of eat-2. We propose that eat-18 and eat-2 function in a multisubunit protein complex involved in the function of a pharyngeal nAChR.


2014 ◽  
Vol 112 (4) ◽  
pp. 951-961 ◽  
Author(s):  
Nicholas F. Trojanowski ◽  
Olivia Padovan-Merhar ◽  
David M. Raizen ◽  
Christopher Fang-Yen

Degenerate networks, in which structurally distinct elements can perform the same function or yield the same output, are ubiquitous in biology. Degeneracy contributes to the robustness and adaptability of networks in varied environmental and evolutionary contexts. However, how degenerate neural networks regulate behavior in vivo is poorly understood, especially at the genetic level. Here, we identify degenerate neural and genetic mechanisms that underlie excitation of the pharynx (feeding organ) in the nematode Caenorhabditis elegans using cell-specific optogenetic excitation and inhibition. We show that the pharyngeal neurons MC, M2, M4, and I1 form multiple direct and indirect excitatory pathways in a robust network for control of pharyngeal pumping. I1 excites pumping via MC and M2 in a state-dependent manner. We identify nicotinic and muscarinic receptors through which the pharyngeal network regulates feeding rate. These results identify two different mechanisms by which degeneracy is manifest in a neural circuit in vivo.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Nikolaos Charmpilas ◽  
Christoph Ruckenstuhl ◽  
Valentina Sica ◽  
Sabrina Büttner ◽  
Lukas Habernig ◽  
...  

AbstractRecently, we reported that, in mice, hunger causes the autophagy-dependent release of a protein called “acyl-CoA-binding protein” or “diazepam binding inhibitor” (ACBP/DBI) from cells, resulting in an increase in plasma ACBP concentrations. Administration of extra ACBP is orexigenic and obesogenic, while its neutralization is anorexigenic in mice, suggesting that ACBP is a major stimulator of appetite and lipo-anabolism. Accordingly, obese persons have higher circulating ACBP levels than lean individuals, and anorexia nervosa is associated with subnormal ACBP plasma concentrations. Here, we investigated whether ACBP might play a phylogenetically conserved role in appetite stimulation. We found that extracellular ACBP favors sporulation in Saccharomyces cerevisiae, knowing that sporulation is a strategy for yeast to seek new food sources. Moreover, in the nematode Caenorhabditis elegans, ACBP increased the ingestion of bacteria as well as the frequency pharyngeal pumping. These observations indicate that ACBP has a phylogenetically ancient role as a ‘hunger factor’ that favors food intake.


2016 ◽  
Author(s):  
Monika Scholz ◽  
Dylan J. Lynch ◽  
Kyung Suk Lee ◽  
Erel Levine ◽  
David Biron

We describe a scalable automated method for measuring the pharyngeal pumping of Caenorhabditis elegans in controlled environments. Our approach enables unbiased measurements for prolonged periods, a high throughput, and measurements in controlled yet dynamically changing feeding environments. The automated analysis compares well with scoring pumping by visual inspection, a common practice in the field. In addition, we observed overall low rates of pharyngeal pumping and long correlation times when food availability was oscillated.


2021 ◽  
Vol 12 ◽  
Author(s):  
Shimaa M. A. Sayed ◽  
Karsten Siems ◽  
Christian Schmitz-Linneweber ◽  
Walter Luyten ◽  
Nadine Saul

To uncover potential anti-aging capacities of Traditional Chinese Medicine (TCM), the nematode Caenorhabditis elegans was used to investigate the effects of Eucommia ulmoides and Cuscuta chinensis extracts, selected by screening seven TCM extracts, on different healthspan parameters. Nematodes exposed to E. ulmoides and C. chinensis extracts, starting at the young adult stage, exhibited prolonged lifespan and increased survival after heat stress as well as upon exposure to the pathogenic bacterium Photorhabdus luminescens, whereby the survival benefits were monitored after stress initiation at different adult stages. However, only C. chinensis had the ability to enhance physical fitness: the swimming behavior and the pharyngeal pumping rate of C. elegans were improved at day 7 and especially at day 12 of adulthood. Finally, monitoring the red fluorescence of aged worms revealed that only C. chinensis extracts caused suppression of intestinal autofluorescence, a known marker of aging. The results underline the different modes of action of the tested plants extracts. E. ulmoides improved specifically the physiological fitness by increasing the survival probability of C. elegans after stress, while C. chinensis seems to be an overall healthspan enhancer, reflected in the suppressed autofluorescence, with beneficial effects on physical as well as physiological fitness. The C. chinensis effects may be hormetic: this is supported by increased gene expression of hsp-16.1 and by trend, also of hsp-12.6.


2018 ◽  
Vol 11 (2) ◽  
pp. 759-767 ◽  
Author(s):  
A. O. Zeltukhin ◽  
G. V. Ilyinskaya ◽  
A. V. Budanov ◽  
P. M. Chumakov

In mammals a small family of genes called Sestrins play important roles in the maintenance of metabolic and redox homeostasis, suggesting that the genes may positively affect the lifespan and counteract the age-related functional decline. The nematode genome contains a single cSesn gene that makes the Caenorhabditis elegans an excellent model for studying functions of the sestrin family. We describe phenotypic differences of worms that have compromised expression of cSesn gene. By comparing three different cSesn-deficient modes with the wild-type C. elegans strain we show that the abrogation of cSesn expression results in an increased body size, an extended period of body growth, a reduces brood size and number of offspring per a single worm, an accelerated decline in muscular functions revealed as a rapid decrease in the pharyngeal pumping rate and in the overall locomotory activity. The results are consistent with the potential roles of cSesn in counteracting the process of aging in C. elegans.


Genetics ◽  
2001 ◽  
Vol 158 (1) ◽  
pp. 221-235 ◽  
Author(s):  
Alexander M van der Linden ◽  
Femke Simmer ◽  
Edwin Cuppen ◽  
Ronald H A Plasterk

Abstract The genome of Caenorhabditis elegans harbors two genes for G-protein β-subunits. Here, we describe the characterization of the second G-protein β-subunit gene gpb-2. In contrast to gpb-1, gpb-2 is not an essential gene even though, like gpb-1, gpb-2 is expressed during development, in the nervous system, and in muscle cells. A loss-of-function mutation in gpb-2 produces a variety of behavioral defects, including delayed egg laying and reduced pharyngeal pumping. Genetic analysis shows that GPB-2 interacts with the GOA-1 (homologue of mammalian Goα) and EGL-30 (homologue of mammalian Gqα) signaling pathways. GPB-2 is most similar to the divergent mammalian Gβ5 subunit, which has been shown to mediate a specific interaction with a Gγ-subunit-like (GGL) domain of RGS proteins. We show here that GPB-2 physically and genetically interacts with the GGL-containing RGS proteins EGL-10 and EAT-16. Taken together, our results suggest that GPB-2 works in concert with the RGS proteins EGL-10 and EAT-16 to regulate GOA-1 (Goα) and EGL-30 (Gqα) signaling.


2021 ◽  
Vol 14 (2) ◽  
pp. 153
Author(s):  
Alexander P. Gerhard ◽  
Jürgen Krücken ◽  
Cedric Neveu ◽  
Claude L. Charvet ◽  
Abdallah Harmache ◽  
...  

Macrocyclic lactones (MLs) are widely used drugs to treat and prevent parasitic nematode infections. In many nematode species including a major pathogen of foals, Parascaris univalens, resistance against MLs is widespread, but the underlying resistance mechanisms and ML penetration routes into nematodes remain unknown. Here, we examined how the P-glycoprotein efflux pumps, candidate genes for ML resistance, can modulate drug susceptibility and investigated the role of active drug ingestion for ML susceptibility in the model nematode Caenorhabditis elegans. Wildtype or transgenic worms, modified to overexpress P. univalens PGP-9 (Pun-PGP-9) at the intestine or epidermis, were incubated with ivermectin or moxidectin in the presence (bacteria or serotonin) or absence (no specific stimulus) of pharyngeal pumping (PP). Active drug ingestion by PP was identified as an important factor for ivermectin susceptibility, while moxidectin susceptibility was only moderately affected. Intestinal Pun-PGP-9 expression elicited a protective effect against ivermectin and moxidectin only in the presence of PP stimulation. Conversely, epidermal Pun-PGP-9 expression protected against moxidectin regardless of PP and against ivermectin only in the absence of active drug ingestion. Our results demonstrate the role of active drug ingestion by nematodes for susceptibility and provide functional evidence for the contribution of P-glycoproteins to ML resistance in a tissue-specific manner.


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