scholarly journals Caenorhabditis elegans nematodes are not attracted to the terrestrial isopod Porcellio scaber

2020 ◽  
Author(s):  
Heather Archer ◽  
Selina Deiparine ◽  
Erik C. Andersen
Keyword(s):  
Caenorhabditis Elegans ◽  
Wild Strain ◽  
Adult Life ◽  
The Body ◽  
Natural Environments ◽  
Porcellio Scaber ◽  
Wild Isolate ◽  
Terrestrial Isopods ◽  
C Elegans ◽  
Different Strains

ABSTRACTPhoresy is a behavior in which an organism, the phoront, travels from one location to another by ‘hitching a ride’ on the body of a host as it disperses. Some phoronts are generalists, taking advantage of any available host. Others are specialists and travel only when specific hosts are located using chemical cues to identify and move (chemotax) toward the preferred host. Free-living nematodes, like Caenorhabditis elegans, are often found in natural environments that contain terrestrial isopods and other invertebrates. Additionally, the C. elegans wild strain PB306 was isolated associated with the isopod Porcellio scaber. However, it is currently unclear if C. elegans is a phoront of terrestrial isopods, and if so, whether it is a specialist, generalist, or developmental stage-specific combination of both strategies. Because the relevant chemical stimuli might be secreted compounds or volatile odorants, we used different types of chemotaxis assays across diverse extractions of compounds or odorants to test whether C. elegans is attracted to P. scaber. We show that two different strains – the wild isolate PB306 and the laboratory-adapted strain N2 – are not attracted to P. scaber during either the dauer or adult life stages. Our results indicate that C. elegans was not attracted to chemical compounds or volatile odorants from P. scaber, providing valuable empirical evidence to suggest that any associations between these two species are likely opportunistic rather than specific phoresy.

scholarly journals Genetic, Behavioral and Environmental Determinants of Male Longevity in Caenorhabditis elegans

Genetics ◽  
2000 ◽  
Vol 154 (4) ◽  
pp. 1597-1610 ◽  
Author(s):  
David Gems ◽  
Donald L Riddle
Keyword(s):  
Caenorhabditis Elegans ◽  
Life Span ◽  
Wild Type ◽  
Neuronal Function ◽  
Nematode Caenorhabditis Elegans ◽  
Wild Isolate ◽  
Young Males ◽  
C Elegans ◽  
Single Sex ◽  
Solitary Males

Abstract Males of the nematode Caenorhabditis elegans are shorter lived than hermaphrodites when maintained in single-sex groups. We observed that groups of young males form clumps and that solitary males live longer, indicating that male-male interactions reduce life span. By contrast, grouped or isolated hermaphrodites exhibited the same longevity. In one wild isolate of C. elegans, AB2, there was evidence of copulation between males. Nine uncoordinated (unc) mutations were used to block clumping behavior. These mutations had little effect on hermaphrodite life span in most cases, yet many increased male longevity even beyond that of solitary wild-type males. In one case, the neuronal function mutant unc-64(e246), hermaphrodite life span was also increased by up to 60%. The longevity of unc-4(e120), unc-13(e51), and unc-32(e189) males exceeded that of hermaphrodites by 70–120%. This difference appears to reflect a difference in sex-specific life span potential revealed in the absence of male behavior that is detrimental to survival. The greater longevity of males appears not to be affected by daf-2, but is influenced by daf-16. In the absence of male-male interactions, median (but not maximum) male life span was variable. This variability was reduced when dead bacteria were used as food. Maintenance on dead bacteria extended both male and hermaphrodite longevity.

scholarly journals Mutations Affecting Nerve Attachment of Caenorhabditis elegans

Genetics ◽  
2001 ◽  
Vol 157 (4) ◽  
pp. 1611-1622 ◽  
Author(s):  
Go Shioi ◽  
Michinari Shoji ◽  
Masashi Nakamura ◽  
Takeshi Ishihara ◽  
Isao Katsura ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Nerve Cord ◽  
Ventral Nerve Cord ◽  
Body Wall ◽  
The Body ◽  
Genetic Loci ◽  
Muscle Attachment ◽  
C Elegans ◽  
Ventral Cord ◽  
Excretory Canal

Abstract Using a pan-neuronal GFP marker, a morphological screen was performed to detect Caenorhabditis elegans larval lethal mutants with severely disorganized major nerve cords. We recovered and characterized 21 mutants that displayed displacement or detachment of the ventral nerve cord from the body wall (Ven: ventral cord abnormal). Six mutations defined three novel genetic loci: ven-1, ven-2, and ven-3. Fifteen mutations proved to be alleles of previously identified muscle attachment/positioning genes, mup-4, mua-1, mua-5, and mua-6. All the mutants also displayed muscle attachment/positioning defects characteristic of mua/mup mutants. The pan-neuronal GFP marker also revealed that mutants of other mua/mup loci, such as mup-1, mup-2, and mua-2, exhibited the Ven defect. The hypodermis, the excretory canal, and the gonad were morphologically abnormal in some of the mutants. The pleiotropic nature of the defects indicates that ven and mua/mup genes are required generally for the maintenance of attachment of tissues to the body wall in C. elegans.

scholarly journals Screening for Presenilin Inhibitors Using the Free-Living Nematode, Caenorhabditis elegans

2004 ◽  
Vol 9 (2) ◽  
pp. 147-152 ◽  
Author(s):  
Brenda R. Ellerbrock ◽  
Eileen M. Coscarelli ◽  
Mark E. Gurney ◽  
Timothy G. Geary
Keyword(s):  
Caenorhabditis Elegans ◽  
High Throughput Screening ◽  
Screening Method ◽  
Genetic System ◽  
Body Cavity ◽  
Egg Laying ◽  
The Body ◽  
Loss Of Function ◽  
C Elegans ◽  
Automated Method

Caenorhabditis elegans contains 3 homologs of presenilin genes that are associated with Alzheimer s disease. Loss-of-function mutations in C. elegans genes cause a defect in egg laying. In humans, loss of presenilin-1 (PS1) function reduces amyloid-beta peptide processing from the amyloid protein precursor. Worms were screened for compounds that block egg laying, phenocopying presenilin loss of function. To accommodate even relatively high throughput screening, a semi-automated method to quantify egg laying was devised by measuring the chitinase released into the culture medium. Chitinase is released by hatching eggs, but little is shed into the medium from the body cavity of a hermaphrodite with an egg laying deficient ( egl) phenotype. Assay validation involved measuring chitinase release from wild-type C. elegans (N2 strain), sel-12 presenilin loss-of-function mutants, and 2 strains of C. elegans with mutations in the egl-36K+ channel gene. Failure to find specific presenilin inhibitors in this collection likely reflects the small number of compounds tested, rather than a flaw in screening strategy. Absent defined biochemical pathways for presenilin, this screening method, which takes advantage of the genetic system available in C. elegans and its historical use for anthelminthic screening, permits an entry into mechanism-based discovery of drugs for Alzheimer s disease. ( Journal of Biomolecular Screening 2004:147-152)

Purification and physical properties of nematode mini-titins and their relation to twitchin

1991 ◽  
Vol 98 (4) ◽  
pp. 491-496
Author(s):  
R. Nave ◽  
D. Furst ◽  
U. Vinkemeier ◽  
K. Weber
Keyword(s):  
Caenorhabditis Elegans ◽  
Immunofluorescence Microscopy ◽  
Apparent Molecular Weight ◽  
The Body ◽  
Wild Type ◽  
Normal Muscle ◽  
Insect Muscle ◽  
C Elegans ◽  
Type C ◽  
Beta Structure

We have isolated mini-titin from the nematodes Ascaris lumbricoides and Caenorhabditis elegans under native conditions using a modification in the procedure to prepare this protein from insect muscle. The proteins have an apparent molecular weight of 600,000 and appear in oriented specimens as flexible thin rods with a length around 240–250 nm. The circular dichroism spectrum of the Ascaris protein is dominated by beta-structure. The proteins react with antibodies to insect mini-titin and also with antibodies raised against peptides contained in the sequence predicted for twitchin, the product of the Caenorhabditis elegans unc-22 gene. Antibodies to insect mini-titin decorate the body musculature as well as the pharynx of wild-type C. elegans in immunofluorescence microscopy. In the twitchin mutant E66 only the pharynx is decorated. We conclude that the mini-titins of invertebrate muscles defined earlier by ultrastructural criteria are very likely to be twitchins, i.e. molecules necessary for normal muscle contraction. We discuss the molecular properties of the proteins in the light of the sequence established for twitchin.

scholarly journals The Caenorhabditis elegans homologue of the extracellular calcium binding protein SPARC/osteonectin affects nematode body morphology and mobility.

1993 ◽  
Vol 4 (9) ◽  
pp. 941-952 ◽  
Author(s):  
J E Schwarzbauer ◽  
C S Spencer
Keyword(s):  
Extracellular Matrix ◽  
Caenorhabditis Elegans ◽  
Calcium Binding ◽  
Fusion Gene ◽  
Muscle Cells ◽  
Gene Organization ◽  
The Body ◽  
Matrix Assembly ◽  
Developmentally Regulated ◽  
C Elegans

The extracellular matrix-associated protein, SPARC (osteonectin [Secreted Protein Acidic and Rich in Cysteine]), modulates cell adhesion and induces a change in cell morphology. SPARC expression in mammals is developmentally regulated and is highest at sites of extracellular matrix assembly and remodeling such as parietal endoderm and bone. We have isolated cDNA and genomic DNA clones encoding the Caenorhabditis elegans homologue of SPARC. The gene organization is highly conserved, and the proteins encoded by mouse, human, and nematode genes are about 38% identical. SPARC consists of four domains (I-IV) based on predicted secondary structure. Using bacterial fusion proteins containing nematode domain I or the domain IV EF-hand motif, we show that, like the mammalian proteins, both domains bind calcium. In transgenic nematodes expressing a SPARC-lacZ fusion gene, beta-galactosidase staining accumulated in a striated pattern in the more heavily stained muscle cells along the body. Comparison of the pattern of transgene expression to unc-54-lacZ animals demonstrated that SPARC is expressed by body wall and sex muscle cells. Appropriate levels of SPARC are essential for normal C. elegans development and muscle function. Transgenic nematodes overexpressing the wild-type SPARC gene were abnormal. Embryos were deformed, and adult hermaphrodites had vulval protrusions and an uncoordinated (Unc) phenotype with reduced mobility and paralysis.

scholarly journals Chlorophyll enhances oxidative stress tolerance inCaenorhabditis elegansand extends its lifespan

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1879 ◽  
Author(s):  
Erjia Wang ◽  
Michael Wink
Keyword(s):  
Oxidative Stress ◽  
Caenorhabditis Elegans ◽  
Secondary Metabolites ◽  
Model System ◽  
The Body ◽  
Aging Effects ◽  
Oxidative Stress Tolerance ◽  
C Elegans ◽  
Dependent Pathway

Green vegetables are thought to be responsible for several beneficial properties such as antioxidant, anti-mutagenic, and detoxification activities. It is not known whether these effects are due to chlorophyll which exists in large amounts in many foods or result from other secondary metabolites. In this study, we used the model systemCaenorhabditis elegansto investigate the anti-oxidative and anti-aging effects of chlorophyllin vivo. We found that chlorophyll significantly improves resistance to oxidative stress. It also enhances the lifespan ofC. elegansby up to 25% via activation of the DAF-16/FOXO-dependent pathway. The results indicate that chlorophyll is absorbed by the worms and is thus bioavailable, constituting an important prerequisite for antioxidant and longevity-promoting activities inside the body. Our study thereby supports the view that green vegetables may also be beneficial for humans.

scholarly journals Three-dimensional simulation of the Caenorhabditis elegans body and muscle cells in liquid and gel environments for behavioural analysis

2018 ◽  
Vol 373 (1758) ◽  
pp. 20170376 ◽  
Author(s):  
Andrey Palyanov ◽  
Sergey Khayrulin ◽  
Stephen D. Larson
Keyword(s):  
Caenorhabditis Elegans ◽  
Muscle Activation ◽  
Body Wall ◽  
Particle System ◽  
Three Dimensional ◽  
Muscle Cells ◽  
The Body ◽  
C Elegans ◽  
Muscle Activation Patterns ◽  
Simulation Engine

To better understand how a nervous system controls the movements of an organism, we have created a three-dimensional computational biomechanical model of the Caenorhabditis elegans body based on real anatomical structure. The body model is created with a particle system–based simulation engine known as Sibernetic, which implements the smoothed particle–hydrodynamics algorithm. The model includes an elastic body-wall cuticle subject to hydrostatic pressure. This cuticle is then driven by body-wall muscle cells that contract and relax, whose positions and shape are mapped from C. elegans anatomy, and determined from light microscopy and electron micrograph data. We show that by using different muscle activation patterns, this model is capable of producing C. elegans -like behaviours, including crawling and swimming locomotion in environments with different viscosities, while fitting multiple additional known biomechanical properties of the animal.  This article is part of a discussion meeting issue ‘Connectome to behaviour: modelling C. elegans at cellular resolution’.

Assessment of lead toxicity on locomotion and growth in a nematode Caenorhabditis elegans

2020 ◽  
Vol 12 (1) ◽  
pp. 36-41
Author(s):  
Shashank Shekhar Tiwari ◽  
Francis Tambo ◽  
Rakhi Agarwal
Keyword(s):  
Caenorhabditis Elegans ◽  
Lead Exposure ◽  
Anthropogenic Activities ◽  
Model Organism ◽  
Lead Toxicity ◽  
Future Generation ◽  
Exposure Dose ◽  
The Body ◽  
Young Generation ◽  
C Elegans

Due to anthropogenic activities and natural abundance, lead exposure is a common phenomenon. Neurotoxic and genotoxic effects of lead are widely known. Recent studies have suggested that lead exposure can affect young generation and transfer to the progeny thus posing a great threat for future generation. The present study was focused on lead toxicity in terms of locomotion and growth of Caenorhabditis elegans (N2 wild type) at three sub-lethal doses (3µM, 15 µM and 30 µM) of Pb (NO3)2 for 24 hours (sub-chronic exposure). Caenorhabditis elegans is a nematode with an established eco- toxicity marker model organism, due to its short life cycle and ease to monitor. After lead  exposure, significant toxic manifestations were observed in locomotion of the nematode in terms of omega bends (+350% for 30 µM exposure dose, p<0.001), reversals (-26.98%, -49% and -66.35% for 3 µM, 15 µM and 30 µM exposure doses respectively, p<0.001), turn counts (-38.66%, -62.61% and -81.93% for 3 µM, 15 µM and 30 µM exposure doses respectively, p<0.001 ) and peristaltic speed alterations (+97.83%, +225.92% and +454.63% for 3 µM, 15 µM and 30 µM exposure doses respectively, p<0.001). Successive reduction in the body length at lower doses shows remarkable toxic alterations in nematodes. The obtained data may be useful to extrapolate the effects of lead exposure on humans, as many of the similar pathways and cellular processes affected by Pb in humans are also present in C. elegans.

Water Content and Water Activity in the Cuticle of Terrestrial Isopods

1972 ◽  
Vol 56 (1) ◽  
pp. 49-55
Author(s):  
OSSI V. LINDQVIST ◽  
INGA SALMINEN ◽  
PAUL W. WINSTON
Keyword(s):  
Body Weight ◽  
Water Content ◽  
Water Activity ◽  
Equilibrium Points ◽  
The Body ◽  
Porcellio Scaber ◽  
Terrestrial Isopods ◽  
Osmotic Equilibrium ◽  
Significant Difference ◽  
The Difference

1. The water content of the cuticle of both desiccated and non-desiccated terrestrial isopods Porcellio scaber and Armadillidium vulgare was measured. The animals were desiccated for various times (up to 3 h) over silica gel and the mean water content of the cuticle was 54.0±0.78% for P. scaber and 52.7±1.11% for A. vulgare. There was no trend as regards the desiccation time, nor did the body weight affect the water content. 2. The water content of the cuticle remained virtually unchanged as long as the animal was alive in the desiccator. It dropped significantly after the animal had died after having lost some 30% of its body weight. 3. The cuticular water content of non-desiccated P. scaber tended to be slightly higher than that of desiccated ones. In A. vulgare no significant difference was observed between non-desiccated and desiccated specimens. 4. The water activity of the excised cuticle of the above two species and of Oniscus asellus and Cylisticus convexus was above that of the haemolymph and therefore not in osmotic equilibrium with it. The osmotic equilibrium points were below the osmotic pressures of the blood; the difference amounted from 1.5 to 2.8 atm. in different species. 5. The difference in water activity between blood and cuticle, the maintenance of water content with desiccation, and the drop in water level at death, all indicate the presence of an active mechanism regulating the cuticular water in terrestrial isopods.

scholarly journals A Putative Catenin–Cadherin System Mediates Morphogenesis of the Caenorhabditis elegans Embryo

1998 ◽  
Vol 141 (1) ◽  
pp. 297-308 ◽  
Author(s):  
Michael Costa ◽  
William Raich ◽  
Cristina Agbunag ◽  
Ben Leung ◽  
Jeff Hardin ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Caenorhabditis Elegans ◽  
Cell Shape ◽  
Shape Change ◽  
Adherens Junctions ◽  
The Body ◽  
C Elegans ◽  
Cell Shape Change ◽  
Filament Bundles ◽  
Cell Adhesion Proteins

During morphogenesis of the Caenorhabditis elegans embryo, hypodermal (or epidermal) cells migrate to enclose the embryo in an epithelium and, subsequently, change shape coordinately to elongate the body (Priess, J.R., and D.I. Hirsh. 1986. Dev. Biol. 117:156– 173; Williams-Masson, E.M., A.N. Malik, and J. Hardin. 1997. Development [Camb.]. 124:2889–2901). We have isolated mutants defective in morphogenesis that identify three genes required for both cell migration during body enclosure and cell shape change during body elongation. Analyses of hmp-1, hmp-2, and hmr-1 mutants suggest that products of these genes anchor contractile actin filament bundles at the adherens junctions between hypodermal cells and, thereby, transmit the force of bundle contraction into cell shape change. The protein products of all three genes localize to hypodermal adherens junctions in embryos. The sequences of the predicted HMP-1, HMP-2, and HMR-1 proteins are related to the cell adhesion proteins α-catenin, β-catenin/Armadillo, and classical cadherin, respectively. This putative catenin–cadherin system is not essential for general cell adhesion in the C. elegans embryo, but rather mediates specific aspects of morphogenetic cell shape change and cytoskeletal organization.

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