A cell that dies during wild-type C. elegans development can function as a neuron in a ced-3 mutant

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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Katanin controls mitotic and meiotic spindle length

The Journal of Cell Biology ◽

10.1083/jcb.200608117 ◽

2006 ◽

Vol 175 (6) ◽

pp. 881-891 ◽

Cited By ~ 198

Author(s):

Karen McNally ◽

Anjon Audhya ◽

Karen Oegema ◽

Francis J. McNally

Keyword(s):

Chromosome Segregation ◽

Eukaryotic Cell ◽

Meiotic Spindle ◽

Mitotic Spindles ◽

Wild Type ◽

Female Meiosis ◽

C Elegans ◽

Microtubule Severing ◽

Spindle Poles ◽

Type C

Accurate control of spindle length is a conserved feature of eukaryotic cell division. Lengthening of mitotic spindles contributes to chromosome segregation and cytokinesis during mitosis in animals and fungi. In contrast, spindle shortening may contribute to conservation of egg cytoplasm during female meiosis. Katanin is a microtubule-severing enzyme that is concentrated at mitotic and meiotic spindle poles in animals. We show that inhibition of katanin slows the rate of spindle shortening in nocodazole-treated mammalian fibroblasts and in untreated Caenorhabditis elegans meiotic embryos. Wild-type C. elegans meiotic spindle shortening proceeds through an early katanin-independent phase marked by increasing microtubule density and a second, katanin-dependent phase that occurs after microtubule density stops increasing. In addition, double-mutant analysis indicated that γ-tubulin–dependent nucleation and microtubule severing may provide redundant mechanisms for increasing microtubule number during the early stages of meiotic spindle assembly.

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ACaenorhabditis elegansPheromone Antagonizes Volatile Anesthetic Action Through a Go-Coupled Pathway

Genetics ◽

10.1093/genetics/161.1.109 ◽

2002 ◽

Vol 161 (1) ◽

pp. 109-119 ◽

Cited By ~ 1

Author(s):

Bruno van Swinderen ◽

Laura B Metz ◽

Laynie D Shebester ◽

C Michael Crowder

Keyword(s):

Sensory Neurons ◽

Volatile Anesthetic ◽

Loss Of Function ◽

Wild Type ◽

C Elegans ◽

Pheromone Activity ◽

Dauer Formation ◽

Anesthetic Action ◽

Nervous System Function ◽

Type C

AbstractVolatile anesthetics (VAs) disrupt nervous system function by an ill-defined mechanism with no known specific antagonists. During the course of characterizing the response of the nematode C. elegans to VAs, we discovered that a C. elegans pheromone antagonizes the VA halothane. Acute exposure to pheromone rendered wild-type C. elegans resistant to clinical concentrations of halothane, increasing the EC50 from 0.43 ± 0.03 to 0.90 ± 0.02. C. elegans mutants that disrupt the function of sensory neurons required for the action of the previously characterized dauer pheromone blocked pheromone-induced resistance (Pir) to halothane. Pheromone preparations from loss-of-function mutants of daf-22, a gene required for dauer pheromone production, lacked the halothane-resistance activity, suggesting that dauer and Pir pheromone are identical. However, the pathways for pheromone’s effects on dauer formation and VA action were not identical. Not all mutations that alter dauer formation affected the Pir phenotype. Further, mutations in genes not known to be involved in dauer formation completely blocked Pir, including those altering signaling through the G proteins Goα and Gqα. A model in which sensory neurons transduce the pheromone activity through antagonistic Go and Gq pathways, modulating VA action against neurotransmitter release machinery, is proposed.

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A novel disintegrin domain protein affects early cell type specification and pattern formation inDictyostelium

Development ◽

10.1242/dev.129.10.2381 ◽

2002 ◽

Vol 129 (10) ◽

pp. 2381-2389

Author(s):

Timothy R. Varney ◽

Hoa Ho ◽

Chere’ Petty ◽

Daphne D. Blumberg

Keyword(s):

Cell Fate ◽

Cellular Slime Mold ◽

Wild Type ◽

Cell Type ◽

C Elegans ◽

Disintegrin Domain ◽

A Cell ◽

Cellular Slime ◽

And Migration ◽

Type Specification

The cellular slime mold, Dictyostelium discoideum is a non-metazoan organism, yet we now demonstrate that a disintegrin domain-containing protein, the product of the ampA gene, plays a role in cell type specification. Disintegrin domain-containing proteins are involved in Notch signaling in Drosophila and C. elegans via an ectodomain shedding mechanism that depends on a metalloprotease domain. The Dictyostelium protein lacks a metalloprotease domain. Nonetheless, analysis of cell type specific reporter gene expression during development of the ampA null strain identifies patterning defects that define two distinct roles for the AmpA protein in specifying cell fate. In the absence of a functional ampA gene, cells prematurely specify as prespore cells. Prestalk cell differentiation and migration are delayed. Both of these defects can be rescued by the inclusion of 10% wild-type cells in the developing null mutant aggregates, indicating that the defect is non-cell autonomous. The ampA gene is also demonstrated to be necessary in a cell-autonomous manner for the correct localization of anterior-like cells to the upper cup of the fruiting body. When derived from ampA null cells, the anterior-like cells are unable to localize to positions in the interior of the developing mounds. Wild-type cells can rescue defects in morphogenesis by substituting for null cells when they differentiate as anterior-like cells, but they cannot rescue the ability of ampA null cells to fill this role. Thus, in spite of its simpler structure, the Dictyostelium ampA protein carries out the same diversity of functions that have been observed for the ADAM and ADAMTS families in metazoans.

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Genetic Differences Affecting the Potency of Stereoisomers of Isoflurane

Anesthesiology ◽

10.1097/00000542-199608000-00021 ◽

1996 ◽

Vol 85 (2) ◽

pp. 385-392 ◽

Cited By ~ 12

Author(s):

Phil G. Morgan ◽

Marianne F. Usiak ◽

Margaret M. Sedensky

Keyword(s):

Volatile Anesthetic ◽

Genetic Differences ◽

Wild Type ◽

C Elegans ◽

Mutant Strains ◽

Anesthetic Action ◽

Type C ◽

Sites Of Action ◽

Standard Techniques

Background In previous studies, researchers demonstrated the ability of a variety of organisms and in vitro sites of anesthetic action to distinguish between stereoisomers of isoflurane or halothane. However, it was not shown whether organisms with differing sensitivities to stereoisomers of one volatile anesthetic are able to distinguish between stereoisomers of another. In this study, the responses of mutants of Caenorbabditis elegans to stereoisomers of isoflurane were determined for comparison to previous results in halothane. Methods Mutant strains of C. elegans were isolated and grown by standard techniques. The EC50s (the effective concentrations of anesthetia at which 50% of the animals are immobilized for 10 s) of stereoisomers of isoflurane and the racemate were determined in wild type and mutant strains of C. elegans. Results Wild type C. elegans and strains with high EC50S of the racemate were more sensitive to the (+) isomer of isoflurane by approximately 30%. The racemate showed a EC50s similar to the less potent isomer, the (-) form. In the strains with low EC50s, one strain showed no ability to differentiate between the stereoisomers, whereas two showed a 60% difference between the (+) and (-) forms. Conclusions The ability to distinguish between stereoisomers of isoflurane is associated with genetic loci separate from those that distinguish between stereoisomers of halothane. These results are consistent with multiple sites of action for these anesthetics.

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Extrinsic repair of injured dendrites as a paradigm for regeneration by fusion

10.1101/062372 ◽

2016 ◽

Author(s):

Meital Oren-Suissa ◽

Tamar Gattegno ◽

Veronika Kravtsov ◽

Benjamin Podbilewicz

Keyword(s):

Axonal Regeneration ◽

Wild Type ◽

C Elegans ◽

Enveloped Virus ◽

Neuronal Dendrites ◽

A Cell ◽

The Central Nervous System ◽

Regenerative Ability ◽

Genetically Determined ◽

Neuronal Arborization

AbstractInjury triggers regeneration of axons and dendrites. Research identified factors required for axonal regeneration outside the CNS, but little is known about regeneration triggered by dendrotomy. Here we study neuronal plasticity triggered by dendrotomy and determine the fate of complex PVD arbors following laser surgery of dendrites. We find that severed primary dendrites grow towards each other and reconnect via branch fusion. Simultaneously, terminal branches lose self-avoidance and grow towards each other, meeting and fusing at the tips via an AFF-1-mediated process. Ectopic branch growth is identified as a step in the regeneration process required for bypassing the lesion site. Failure of reconnection to the severed dendrites results in degeneration of the distal end of the neuron. We discover pruning of excess branches via EFF-1 that acts to recover the original wild-type arborization pattern in a cell-autonomous process. In contrast, AFF-1 activity during dendritic auto-fusion is derived from the lateral seam cells and not autonomously from the PVD neuron. We propose a model in which AFF-1-vesicles derived from the epidermal seam cells fuse neuronal dendrites from without. Thus, EFF-1 and AFF-1 fusion proteins emerge as new players in neuronal arborization and maintenance of arbor connectivity following injury inC. elegans. Our results demonstrate that there is a genetically determined multi-step pathway to repair broken dendrites in which EFF-1 and AFF-1 act on different steps of the pathway. Intrinsic EFF-1 is essential for dendritic pruning after injury and extrinsic AFF-1 mediates dendrite fusion to bypass injuries.Author summaryNeurons in the central nervous system have very limited regenerative ability, they fail to remodel following amputation and only in some invertebrates, axons can repair themselves by fusion. Some genetic pathways have been identified for axonal regeneration but few studies exist on dendrite regeneration following injury. To determine how neurons regenerate dendrites following injury we study theC. elegansPVD polymodal neurons that display an arborized pattern of repetitive menorah-like structures. We injure dendrites by laser microsurgery, follow their fate and show that broken primary dendrites often regenerate via fusion. We describe how PVD dendrites regenerate and present roles for EFF-1 and AFF-1 proteins in fusion and remodeling of menorahs. Menorahs lose self-avoidance and AFF-1 fuses them, bypassing the injury site. Branch sprouting, EFF-1-mediated pruning, and arbor simplification completes regeneration. When auto-fusion fails the distal arbor degenerates. Surprisingly, AFF-1 acts non-cell autonomously to mediate dendrite fusion. We propose that extracellular vesicles derived from the lateral epidermis fuse severed dendrites in a process reminiscent of enveloped virus-mediated cell fusion without infection.

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Autophagy promotes visceral aging in wild-type C. elegans

Autophagy ◽

10.1080/15548627.2019.1569919 ◽

2019 ◽

Vol 15 (4) ◽

pp. 731-732 ◽

Cited By ~ 2

Author(s):

Alexandre Benedetto ◽

David Gems

Keyword(s):

Wild Type ◽

C Elegans ◽

Type C

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Multi-omics analysis identifies essential regulators of mitochondrial stress response in two wild-type C. elegans strains

iScience ◽

10.1016/j.isci.2022.103734 ◽

2022 ◽

pp. 103734

Author(s):

Arwen W. Gao ◽

Gaby El Alam ◽

Amélia Lalou ◽

Terytty Yang Li ◽

Marte Molenaars ◽

...

Keyword(s):

Stress Response ◽

Wild Type ◽

Mitochondrial Stress ◽

C Elegans ◽

Omics Analysis ◽

Type C

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Pattern formation in the nematode epidermis: determination of the arrangement of peripheral sense organs in the C. elegans male tail

Development ◽

10.1242/dev.113.2.515 ◽

1991 ◽

Vol 113 (2) ◽

pp. 515-526 ◽

Cited By ~ 9

Author(s):

S.E. Baird ◽

D.H. Fitch ◽

I.A. Kassem ◽

S.W. Emmons

Keyword(s):

Developmental Process ◽

Wild Type ◽

Sense Organs ◽

Male Tail ◽

C Elegans ◽

Active Mechanism ◽

Ray Cells ◽

Indirect Immunofluorescence Staining ◽

A Cell

The developmental process that determines the arrangement of ray sensilla in the Caenorhabditis elegans male tail has been studied. It is shown that the adult arrangement of rays is determined by the placement of ray cells at specific sites in the epidermis of the last larval (L4) stage. Placement of ray cells at specific epidermal sites results from the generation of neurons and support cells in the epidermis near to their final positions, and the subsequent refinement of these positions by an active mechanism involving specific cellular associations. Positions of ray cells and adjacent epidermal cells have been studied during ray development by means of indirect immunofluorescence staining with an antibody to a cell junctional antigen. Mutations are described in six genes that alter the adult arrangement of the rays, frequently resulting in fusion of rays. Changes in the adult pattern of rays in mutants appear to result from prior changes in the epidermal positions of ray cells, and for two mutants it is suggested that this may be due to the inappropriate clustering of processes from neurons and support cells of adjacent rays. Development of the wild-type arrangement of rays appears to require the specification of molecular differences between the rays that affect the specificity of their cellular associations.

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