Ultrastructure of the postcorpus of the esophagus of Teratocephalus lirellus (Teratocephalida) and its use for interpreting character evolution in Secernentea (Nematoda)

2001 ◽  
Vol 79 (1) ◽  
pp. 16-25 ◽  
Author(s):  
Y C Zhang ◽  
J G Baldwin
Keyword(s):  
Caenorhabditis Elegans ◽  
Muscle Cells ◽  
Character Evolution ◽  
Binucleate Cells ◽  
C Elegans ◽  
Esophageal Lumen ◽  
Functional Convergence ◽  
Representative Species ◽  
Basal Bulb ◽  
Radial Muscle

The ultrastructure of the postcorpus of the putative outgroup of Secernentea (Nematoda), Teratocephalus lirellus (Teratocephalida), is compared with previous observations of representative species Zeldia punctata (Cephalobina), Caenorhabditis elegans (Rhabditina), and Diplenteron sp. (Diplogastrina) in order to interpret the evolution of feeding structures within Secernentea. The postcorpus of T. lirellus consists of 6 marginal, 13 muscle, 3 gland, and 11 nerve cells. In both T. lirellus and Z. punctata, one duct from each of two subventral glands opens into the esophageal lumen at the junction of the isthmus and the basal bulb, whereas in C. elegans and Diplenteron sp., homologous openings are at the posterior end of the median bulb. Caenorhabditis elegans and Z. punctata each have two additional glands that open within the basal bulb. The postcorpus of each taxon has four anterior-to-posterior layered sets of radial muscle cells, except in Diplenteron sp., which lacks a grinder and has homologs to the anterior two sets only. The anterior set of muscles of T. lirellus and Z. punctata includes six mononucleate cells, whereas the homolog in C. elegans and Diplenteron sp. includes three binucleate cells. Evaluation of character polarity defines Rhabditina and Diplogastrina as sister taxa, and suggests that the character of five glands may result from functional convergence.

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 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’.

scholarly journals Optogenetic analysis of Ca++ transients in Caenorhabditis elegans muscle cells during forward and reverse locomotion

2020 ◽  
Author(s):  
Jacob R. Manjarrez ◽  
Magera Shaw ◽  
Roger Mailler
Keyword(s):  
Caenorhabditis Elegans ◽  
Muscle Activation ◽  
Cell Activity ◽  
Model Organism ◽  
Muscle Cells ◽  
Phase Lag ◽  
C Elegans ◽  
Calcium Indicators ◽  
Body Wall Muscles ◽  
Genetically Encoded Calcium Indicators

ABSTRACTUnderstanding how an organism generates movement is an important step toward determining how a system of neurons produces behavior. With only 95 body wall muscles and 302 neurons, Caenorhabditis elegans is an attractive model organism to use in uncovering the connection between neural circuitry and movement. This study provides a comprehensive examination of the muscle cell activity used by C. elegans during both forward and reverse locomotion. By tracking freely moving worms that express genetically encoded calcium indicators in their muscle cells, we directly measure the patterns of activity that occur during movement. We then analyzed these patterns using a variety of signal processing and statistical techniques. Although our results agree with many previous findings, we also discovered there is significantly different mean Ca++ levels in many of the muscle cells during forward and reverse locomotion and, when considered independently, the dorsal and ventral muscle activation waves exhibit classical neuromechanical phase lag (NPL).

scholarly journals Type IV Collagen Is Detectable in Most, but Not All, Basement Membranes of Caenorhabditis elegans and Assembles on Tissues That Do Not Express It

1997 ◽  
Vol 137 (5) ◽  
pp. 1171-1183 ◽  
Author(s):  
Patricia L. Graham ◽  
Jeffrey J. Johnson ◽  
Shaoru Wang ◽  
Marion H. Sibley ◽  
Malini C. Gupta ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Body Wall ◽  
Type Iv Collagen ◽  
Fluorescent Protein ◽  
Muscle Cells ◽  
Basement Membranes ◽  
Body Wall Muscle ◽  
Collagen Molecule ◽  
C Elegans ◽  
Type Iv

Type IV collagen in Caenorhabditis elegans is produced by two essential genes, emb-9 and let-2, which encode α1- and α2-like chains, respectively. The distribution of EMB-9 and LET-2 chains has been characterized using chain-specific antisera. The chains colocalize, suggesting that they may function in a single heterotrimeric collagen molecule. Type IV collagen is detected in all basement membranes except those on the pseudocoelomic face of body wall muscle and on the regions of the hypodermis between body wall muscle quadrants, indicating that there are major structural differences between some basement membranes in C. elegans. Using lacZ/green fluorescent protein (GFP) reporter constructs, both type IV collagen genes were shown to be expressed in the same cells, primarily body wall muscles, and some somatic cells of the gonad. Although the pharynx and intestine are covered with basement membranes that contain type IV collagen, these tissues do not express either type IV collagen gene. Using an epitope-tagged emb-9 construct, we show that type IV collagen made in body wall muscle cells can assemble into the pharyngeal, intestinal, and gonadal basement membranes. Additionally, we show that expression of functional type IV collagen only in body wall muscle cells is sufficient for C. elegans to complete development and be partially fertile. Since type IV collagen secreted from muscle cells only assembles into some of the basement membranes that it has access to, there must be a mechanism regulating its assembly. We propose that interaction with a cell surface–associated molecule(s) is required to facilitate type IV collagen assembly.

scholarly journals The BCL-2–like protein CED-9 of C. elegans promotes FZO-1/Mfn1,2– and EAT-3/Opa1–dependent mitochondrial fusion

2009 ◽  
Vol 186 (4) ◽  
pp. 525-540 ◽  
Author(s):  
Stéphane G. Rolland ◽  
Yun Lu ◽  
Charles N. David ◽  
Barbara Conradt
Keyword(s):  
Caenorhabditis Elegans ◽  
Mitochondrial Membrane ◽  
Muscle Cells ◽  
Mitochondrial Fusion ◽  
Mitochondrial Morphology ◽  
Inner Mitochondrial Membrane ◽  
C Elegans

The mammalian dynamin-related guanosine triphosphatases Mfn1,2 and Opa1 are required for mitochondrial fusion. However, how their activities are controlled and coordinated is largely unknown. We present data that implicate the BCL-2–like protein CED-9 in the control of mitochondrial fusion in Caenorhabditis elegans. We demonstrate that CED-9 can promote complete mitochondrial fusion of both the outer and inner mitochondrial membrane. We also show that this fusion is dependent on the C. elegans Mfn1,2 homologue FZO-1 and the C. elegans Opa1 homologue EAT-3. Furthermore, we show that CED-9 physically interacts with FZO-1 in vivo and that the ability of CED-9 to interact with FZO-1 is important for its ability to cause mitochondrial fusion. CED-9–induced mitochondrial fusion is not required for the maintenance of mitochondrial morphology during embryogenesis or in muscle cells, at least under normal conditions and in the absence of stress. Therefore, we propose that the BCL-2–like CED-9 acts through FZO-1/Mfn1,2 and EAT-3/Opa1 to promote mitochondrial fusion in response to specific cellular signals.

scholarly journals Conditional Dominant Mutations in the Caenorhabditis elegans Gene act-2 Identify Cytoplasmic and Muscle Roles for a Redundant Actin Isoform

2006 ◽  
Vol 17 (3) ◽  
pp. 1051-1064 ◽  
Author(s):  
John H. Willis ◽  
Edwin Munro ◽  
Rebecca Lyczak ◽  
Bruce Bowerman
Keyword(s):  
Caenorhabditis Elegans ◽  
Muscle Cells ◽  
Binding Pocket ◽  
Embryonic Cell ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Embryonic Cells ◽  
Actin Isoforms ◽  
C Elegans ◽  
Actin Isoform

Animal genomes each encode multiple highly conserved actin isoforms that polymerize to form the microfilament cytoskeleton. Previous studies of vertebrates and invertebrates have shown that many actin isoforms are restricted to either nonmuscle (cytoplasmic) functions, or to myofibril force generation in muscle cells. We have identified two temperature-sensitive and semidominant embryonic-lethal Caenorhabditis elegans mutants, each with a single mis-sense mutation in act-2, one of five C. elegans genes that encode actin isoforms. These mutations alter conserved and adjacent amino acids predicted to form part of the ATP binding pocket of actin. At the restrictive temperature, both mutations resulted in aberrant distributions of cortical microfilaments associated with abnormal and striking membrane ingressions and protrusions. In contrast to the defects caused by these dominant mis-sense mutations, an act-2 deletion did not result in early embryonic cell division defects, suggesting that additional and redundant actin isoforms are involved. Accordingly, we found that two additional actin isoforms, act-1 and act-3, were required redundantly with act-2 for cytoplasmic function in early embryonic cells. The act-1 and -3 genes also have been implicated previously in muscle function. We found that an ACT-2::GFP reporter was expressed cytoplasmically in embryonic cells and also was incorporated into contractile filaments in adult muscle cells. Furthermore, one of the dominant act-2 mutations resulted in uncoordinated adult movement. We conclude that redundant C. elegans actin isoforms function in both muscle and nonmuscle contractile processes.

The glycomes of Caenorhabditis elegans and other model organisms

2002 ◽  
Vol 69 ◽  
pp. 117-134 ◽  
Author(s):  
Stuart M. Haslam ◽  
David Gems ◽  
Howard R. Morris ◽  
Anne Dell
Keyword(s):  
Caenorhabditis Elegans ◽  
Current Knowledge ◽  
Structural Data ◽  
Model Organisms ◽  
Entire Genome ◽  
C Elegans ◽  
The Face ◽  
Area Of Concern ◽  
Nematode Worm

There is no doubt that the immense amount of information that is being generated by the initial sequencing and secondary interrogation of various genomes will change the face of glycobiological research. However, a major area of concern is that detailed structural knowledge of the ultimate products of genes that are identified as being involved in glycoconjugate biosynthesis is still limited. This is illustrated clearly by the nematode worm Caenorhabditis elegans, which was the first multicellular organism to have its entire genome sequenced. To date, only limited structural data on the glycosylated molecules of this organism have been reported. Our laboratory is addressing this problem by performing detailed MS structural characterization of the N-linked glycans of C. elegans; high-mannose structures dominate, with only minor amounts of complex-type structures. Novel, highly fucosylated truncated structures are also present which are difucosylated on the proximal N-acetylglucosamine of the chitobiose core as well as containing unusual Fucα1–2Gal1–2Man as peripheral structures. The implications of these results in terms of the identification of ligands for genomically predicted lectins and potential glycosyltransferases are discussed in this chapter. Current knowledge on the glycomes of other model organisms such as Dictyostelium discoideum, Saccharomyces cerevisiae and Drosophila melanogaster is also discussed briefly.

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.

scholarly journals Functional Redundancy of the B9 Proteins and Nephrocystins in Caenorhabditis elegans Ciliogenesis

2008 ◽  
Vol 19 (5) ◽  
pp. 2154-2168 ◽  
Author(s):  
Corey L. Williams ◽  
Marlene E. Winkelbauer ◽  
Jenny C. Schafer ◽  
Edward J. Michaud ◽  
Bradley K. Yoder
Keyword(s):  
Caenorhabditis Elegans ◽  
Joubert Syndrome ◽  
Cystic Kidney ◽  
Basal Bodies ◽  
The Novel ◽  
C Elegans ◽  
Human Genes ◽  
Cilia Formation ◽  
Strong Candidate ◽  
Candidate Loci

Meckel-Gruber syndrome (MKS), nephronophthisis (NPHP), and Joubert syndrome (JBTS) are a group of heterogeneous cystic kidney disorders with partially overlapping loci. Many of the proteins associated with these diseases interact and localize to cilia and/or basal bodies. One of these proteins is MKS1, which is disrupted in some MKS patients and contains a B9 motif of unknown function that is found in two other mammalian proteins, B9D2 and B9D1. Caenorhabditis elegans also has three B9 proteins: XBX-7 (MKS1), TZA-1 (B9D2), and TZA-2 (B9D1). Herein, we report that the C. elegans B9 proteins form a complex that localizes to the base of cilia. Mutations in the B9 genes do not overtly affect cilia formation unless they are in combination with a mutation in nph-1 or nph-4, the homologues of human genes (NPHP1 and NPHP4, respectively) that are mutated in some NPHP patients. Our data indicate that the B9 proteins function redundantly with the nephrocystins to regulate the formation and/or maintenance of cilia and dendrites in the amphid and phasmid ciliated sensory neurons. Together, these data suggest that the human homologues of the novel B9 genes B9D2 and B9D1 will be strong candidate loci for pathologies in human MKS, NPHP, and JBTS.

scholarly journals Characterization of Caenorhabditis elegans Homologs of the Down Syndrome Candidate Gene DYRK1A

Genetics ◽  
2003 ◽  
Vol 163 (2) ◽  
pp. 571-580 ◽  
Author(s):  
William B Raich ◽  
Celine Moorman ◽  
Clay O Lacefield ◽  
Jonah Lehrer ◽  
Dusan Bartsch ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Caenorhabditis Elegans ◽  
Trisomy 21 ◽  
Gene Dosage ◽  
Inducible Promoters ◽  
C Elegans ◽  
Dual Specificity ◽  
Specificity Protein

Abstract The pathology of trisomy 21/Down syndrome includes cognitive and memory deficits. Increased expression of the dual-specificity protein kinase DYRK1A kinase (DYRK1A) appears to play a significant role in the neuropathology of Down syndrome. To shed light on the cellular role of DYRK1A and related genes we identified three DYRK/minibrain-like genes in the genome sequence of Caenorhabditis elegans, termed mbk-1, mbk-2, and hpk-1. We found these genes to be widely expressed and to localize to distinct subcellular compartments. We isolated deletion alleles in all three genes and show that loss of mbk-1, the gene most closely related to DYRK1A, causes no obvious defects, while another gene, mbk-2, is essential for viability. The overexpression of DYRK1A in Down syndrome led us to examine the effects of overexpression of its C. elegans ortholog mbk-1. We found that animals containing additional copies of the mbk-1 gene display behavioral defects in chemotaxis toward volatile chemoattractants and that the extent of these defects correlates with mbk-1 gene dosage. Using tissue-specific and inducible promoters, we show that additional copies of mbk-1 can impair olfaction cell-autonomously in mature, fully differentiated neurons and that this impairment is reversible. Our results suggest that increased gene dosage of human DYRK1A in trisomy 21 may disrupt the function of fully differentiated neurons and that this disruption is reversible.

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