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

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.

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Caenorhabditis elegans triple null mutant lacking UDP-N-acetyl-D-glucosamine:α-3-D-mannoside β1,2-N-acetylglucosaminyltransferase I

Biochemical Journal ◽

10.1042/bj20040793 ◽

2004 ◽

Vol 382 (3) ◽

pp. 995-1001 ◽

Cited By ~ 46

Author(s):

Shaoxian ZHU ◽

Andrew HANNEMAN ◽

Vernon N. REINHOLD ◽

Andrew M. SPENCE ◽

Harry SCHACHTER

Keyword(s):

Caenorhabditis Elegans ◽

Chromosome Number ◽

Null Mutant ◽

Wild Type ◽

Knock Out ◽

C Elegans ◽

In The Wild ◽

Wild Type Worm ◽

Type C ◽

Nematode Worm

We have previously reported, from the nematode worm Caenor-habditis elegans, three genes (gly-12, gly-13 and gly-14) encoding enzymically active UDP-N-acetyl-D-glucosamine:α-3-D-mannoside β1,2-N-acetylglucosaminyltransferase I (GnT I), an enzyme essential for hybrid, paucimannose and complex N-glycan synthesis. We now describe a worm with null mutations in all three GnT I genes, gly-14 (III);gly-12 gly-13 (X) (III and X refer to the chromosome number). The triple-knock-out (TKO) worms have a normal phenotype, although they do not express GnT I activity and do not synthesize 31 paucimannose, complex and fucosylated oligomannose N-glycans present in the wild-type worm. The TKO worm has increased amounts of non-fucosylated oligomannose N-glycan structures, a finding consistent with the site of GnT I action. Five fucosylated oligomannose N-glycan structures were observed in TKO, but not wild-type, worms, indicating the presence of unusual GnT I-independent fucosyltransferases. It is concluded that wild-type C. elegans makes a large number of GnT I-dependent N-glycans that are not essential for normal worm development under laboratory conditions. The TKO worm may be more susceptible to mutations in other genes, thereby providing an approach for the identification of genes that interact with GnT I.

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The Tactile Receptive Fields of Freely Moving Caenorhabditis elegans Nematodes

10.1101/259937 ◽

2018 ◽

Author(s):

E. A. Mazzochette ◽

A. L. Nekimken ◽

F. Loizeau ◽

J. Whitworth ◽

B. Huynh ◽

...

Keyword(s):

Caenorhabditis Elegans ◽

Receptive Fields ◽

Behavioral Responses ◽

The Body ◽

Stimulus Strength ◽

Wild Type ◽

C Elegans ◽

Speed Up ◽

Touch Sensation ◽

Freely Moving

AbstractSensory neurons embedded in skin are responsible for the sense of touch. In humans and other mammals, touch sensation depends on thousands of diverse somatosensory neurons. By contrast, Caenorhabditis elegans nematodes have six gentle touch receptor neurons linked to simple behaviors. The classical touch assay uses an eyebrow hair to stimulate freely moving C. elegans, evoking evasive behavioral responses. While this assay has led to the discovery of genes required for touch sensation, it does not provide control over stimulus strength or position. Here, we present an integrated system for performing automated, quantitative touch assays that circumvents these limitations and incorporates automated measurements of behavioral responses. Highly Automated Worm Kicker (HAWK) unites microfabricated silicon force sensors and video analysis with real-time force and position control. Using this system, we stimulated animals along the anterior-posterior axis and compared responses in wild-type and spc-1(dn) transgenic animals, which have a touch defect due to expression of a dominant-negative α spectrin protein fragment. As expected from prior studies, delivering large stimuli anterior to the mid-point of the body evoked a reversal, but such a stimulus applied posterior to the mid-point evoked a speed-up. The probability of evoking a response of either kind depended on stimulus strength and location; once initiated, the magnitude and quality of both reversal and speed-up behavioral responses were uncorrelated with stimulus location, strength, or the absence or presence of the spc-1(dn) transgene. Wild-type animals failed to respond when the stimulus was applied near the mid-point. These results establish that stimulus strength and location govern the activation of a stereotyped motor program and that the C. elegans body surface consists of two receptive fields separated by a gap.

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Experimental investigation using micro-PIV of the effect of microRNA-1 deficiency on motility in Caenorhabditis elegans

10.1101/2020.06.16.119396 ◽

2020 ◽

Author(s):

S. Ravikumar ◽

M. Fedrizzi ◽

R. Prabhakar ◽

R. Pocock ◽

M. K. O’Bryan ◽

...

Keyword(s):

Caenorhabditis Elegans ◽

Swimming Speed ◽

Model Organism ◽

The Body ◽

Wild Type ◽

Mean Power ◽

C Elegans ◽

Micro Piv ◽

Image Velocimetry ◽

Beating Frequency

AbstractCaenorhabditis elegans is a microscopic nematode used extensively as a model organism in studies of neuromuscular function and neurodegenerative disorders. A mutation in mir-1 affects signalling at the neuromuscular junction. We investigate the effect of this mutation on the propulsive power exerted by nematodes as they grow in size with age. We compare the motility of wild-type and mir-1(gk276) mutant nematodes in a Newtonian fluid using a two-component, two dimensional (2C-2D) Digital Microscopic Particle Image Velocimetry (µ-PIV) technique. Beating amplitudes of the head and tail, the wavelength of undulatory waves and the swimming speed scale linearly with size in both the wild-type and mutant strains. The beating frequency is independent of size or position along the body. Differences in the magnitudes of these kinematic parameters between the two strains, however, grow systematically with age. The swimming speed scales linearly with the wave speed of the neuromuscular undulation in both nematode strains with a conserved ratio. The magnitude of mean power and mean local fluid circulation in the mutant is significantly lower compared to those of the wild-type animals of the same age. This indicates that a mutation in mir-1 adversely affects motility in C. elegans.

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

Current Aging Science ◽

10.2174/1874609813999210104203614 ◽

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.

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Sperm Competition in the Absence of Fertilization in Caenorhabditis elegans

Genetics ◽

10.1093/genetics/152.1.201 ◽

1999 ◽

Vol 152 (1) ◽

pp. 201-208 ◽

Cited By ~ 2

Author(s):

Andrew Singson ◽

Katherine L Hill ◽

Steven W L’Hernault

Keyword(s):

Caenorhabditis Elegans ◽

Sperm Competition ◽

Sperm Function ◽

Sperm Precedence ◽

Wild Type ◽

Nematode Caenorhabditis Elegans ◽

C Elegans ◽

Normal Sperm ◽

Self Fertilization ◽

Competition Assays

Abstract Hermaphrodite self-fertilization is the primary mode of reproduction in the nematode Caenorhabditis elegans. However, when a hermaphrodite is crossed with a male, nearly all of the oocytes are fertilized by male-derived sperm. This sperm precedence during reproduction is due to the competitive superiority of male-derived sperm and results in a functional suppression of hermaphrodite self-fertility. In this study, mutant males that inseminate fertilization-defective sperm were used to reveal that sperm competition within a hermaphrodite does not require successful fertilization. However, sperm competition does require normal sperm motility. Additionally, sperm competition is not an absolute process because oocytes not fertilized by male-derived sperm can sometimes be fertilized by hermaphrodite-derived sperm. These results indicate that outcrossed progeny result from a wild-type cross because male-derived sperm are competitively superior and hermaphrodite-derived sperm become unavailable to oocytes. The sperm competition assays described in this study will be useful in further classifying the large number of currently identified mutations that alter sperm function and development in C. elegans.

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Streblus asper Lour. exerts MAPK and SKN-1 mediated anti-aging, anti-photoaging activities and imparts neuroprotection by ameliorating Aβ in Caenorhabditis elegans

Nutrition and Healthy Aging ◽

10.3233/nha-210121 ◽

2021 ◽

pp. 1-17

Author(s):

Mani Iyer Prasanth ◽

James Michael Brimson ◽

Dicson Sheeja Malar ◽

Anchalee Prasansuklab ◽

Tewin Tencomnao

Keyword(s):

Oxidative Stress ◽

Caenorhabditis Elegans ◽

Stress Resistance ◽

Vital Role ◽

Transgenic Strain ◽

Wild Type ◽

Neuroprotective Effects ◽

C Elegans ◽

Streblus Asper

BACKGROUND: Streblus asper Lour., has been reported to have anti-aging and neuroprotective efficacies in vitro. OBJECTIVE: To analyze the anti-aging, anti-photoaging and neuroprotective efficacies of S. asper in Caenorhabditis elegans. METHODS: C. elegans (wild type and gene specific mutants) were treated with S. asper extract and analyzed for lifespan and other health benefits through physiological assays, fluorescence microscopy, qPCR and Western blot. RESULTS: The plant extract was found to increase the lifespan, reduce the accumulation of lipofuscin and modulate the expression of candidate genes. It could extend the lifespan of both daf-16 and daf-2 mutants whereas the pmk-1 mutant showed no effect. The activation of skn-1 was observed in skn-1::GFP transgenic strain and in qPCR expression. Further, the extract can extend the lifespan of UV-A exposed nematodes along with reducing ROS levels. Additionally, the extract also extends lifespan and reduces paralysis in Aβ transgenic strain, apart from reducing Aβ expression. CONCLUSIONS: S. asper was able to extend the lifespan and healthspan of C. elegans which was independent of DAF-16 pathway but dependent on SKN-1 and MAPK which could play a vital role in eliciting the anti-aging, anti-photoaging and neuroprotective effects, as the extract could impart oxidative stress resistance and neuroprotection.

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

Genetics ◽

10.1093/genetics/154.4.1597 ◽

2000 ◽

Vol 154 (4) ◽

pp. 1597-1610 ◽

Cited By ~ 1

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.

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Mutations Affecting Nerve Attachment of Caenorhabditis elegans

Genetics ◽

10.1093/genetics/157.4.1611 ◽

2001 ◽

Vol 157 (4) ◽

pp. 1611-1622 ◽

Cited By ~ 1

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.

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Microtubules and microtubule-associated proteins from the nematode Caenorhabditis elegans: periodic cross-links connect microtubules in vitro.

The Journal of Cell Biology ◽

10.1083/jcb.103.1.23 ◽

1986 ◽

Vol 103 (1) ◽

pp. 23-31 ◽

Cited By ~ 35

Author(s):

E J Aamodt ◽

J G Culotti

Keyword(s):

Caenorhabditis Elegans ◽

Apparent Molecular Weight ◽

Cross Link ◽

Nematode Caenorhabditis Elegans ◽

Microtubule Associated Proteins ◽

C Elegans ◽

Associated Proteins ◽

Cross Links ◽

The Cross

The nematode Caenorhabditis elegans should be an excellent model system in which to study the role of microtubules in mitosis, embryogenesis, morphogenesis, and nerve function. It may be studied by the use of biochemical, genetic, molecular biological, and cell biological approaches. We have purified microtubules and microtubule-associated proteins (MAPs) from C. elegans by the use of the anti-tumor drug taxol (Vallee, R. B., 1982, J. Cell Biol., 92:435-44). Approximately 0.2 mg of microtubules and 0.03 mg of MAPs were isolated from each gram of C. elegans. The C. elegans microtubules were smaller in diameter than bovine microtubules assembled in vitro in the same buffer. They contained primarily 9-11 protofilaments, while the bovine microtubules contained 13 protofilaments. The principal MAP had an apparent molecular weight of 32,000 and the minor MAPs were 30,000, 45,000, 47,000, 50,000, 57,000, and 100,000-110,000 mol wt as determined by SDS-gel electrophoresis. The microtubules were observed, by electron microscopy of negatively stained preparations, to be connected by stretches of highly periodic cross-links. The cross-links connected the adjacent protofilaments of aligned microtubules, and occurred at a frequency of one cross-link every 7.7 +/- 0.9 nm, or one cross-link per tubulin dimer along the protofilament. The cross-links were removed when the MAPs were extracted from the microtubules with 0.4 M NaCl. The cross-links then re-formed when the microtubules and the MAPs were recombined in a low salt buffer. These results strongly suggest that the cross-links are composed of MAPs.

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Goα Regulates Volatile Anesthetic Action in Caenorhabditis elegans

Genetics ◽

10.1093/genetics/158.2.643 ◽

2001 ◽

Vol 158 (2) ◽

pp. 643-655 ◽

Cited By ~ 1

Author(s):

Bruno van Swinderen ◽

Laura B Metz ◽

Laynie D Shebester ◽

Jane E Mendel ◽

Paul W Sternberg ◽

...

Keyword(s):

Caenorhabditis Elegans ◽

Novel Mutation ◽

Volatile Anesthetic ◽

Loss Of Function ◽

Wild Type ◽

Α Subunit ◽

C Elegans ◽

Missense Mutant ◽

Anesthetic Action ◽

Mutant Phenotypes

Abstract To identify genes controlling volatile anesthetic (VA) action, we have screened through existing Caenorhabditis elegans mutants and found that strains with a reduction in Go signaling are VA resistant. Loss-of-function mutants of the gene goa-1, which codes for the α-subunit of Go, have EC50s for the VA isoflurane of 1.7- to 2.4-fold that of wild type. Strains overexpressing egl-10, which codes for an RGS protein negatively regulating goa-1, are also isoflurane resistant. However, sensitivity to halothane, a structurally distinct VA, is differentially affected by Go pathway mutants. The RGS overexpressing strains, a goa-1 missense mutant found to carry a novel mutation near the GTP-binding domain, and eat-16(rf) mutants, which suppress goa-1(gf) mutations, are all halothane resistant; goa-1(null) mutants have wild-type sensitivities. Double mutant strains carrying mutations in both goa-1 and unc-64, which codes for a neuronal syntaxin previously found to regulate VA sensitivity, show that the syntaxin mutant phenotypes depend in part on goa-1 expression. Pharmacological assays using the cholinesterase inhibitor aldicarb suggest that VAs and GOA-1 similarly downregulate cholinergic neurotransmitter release in C. elegans. Thus, the mechanism of action of VAs in C. elegans is regulated by Goα, and presynaptic Goα-effectors are candidate VA molecular targets.

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