scholarly journals Myosin activity drives actomyosin bundle formation and organization in contractile cells of the Caenorhabditis elegans spermatheca

2017 ◽  
Vol 28 (14) ◽  
pp. 1937-1949 ◽  
Author(s):  
Alison C. E. Wirshing ◽  
Erin J. Cram
Keyword(s):  
Smooth Muscle ◽  
Caenorhabditis Elegans ◽  
Force Production ◽  
Myoepithelial Cells ◽  
Stress Fibers ◽  
C Elegans ◽  
Cell Stretch ◽  
Bundle Size ◽  
Contractile Cells

Stress fibers—contractile actomyosin bundles—are important for cellular force production and adaptation to physical stress and have been well studied within the context of cell migration. However, less is known about actomyosin bundle formation and organization in vivo and in specialized contractile cells, such as smooth muscle and myoepithelial cells. The Caenorhabditis elegans spermatheca is a bag-like organ of 24 myoepithelial cells that houses the sperm and is the site of fertilization. During ovulation, spermathecal cells are stretched by oocyte entry and then coordinately contract to expel the fertilized embryo into the uterus. Here we use four-dimensional confocal microscopy of live animals to observe changes to spermathecal actomyosin network organization during cell stretch and contraction. Oocyte entry is required to trigger cell contraction and concomitant production of parallel actomyosin bundles. Actomyosin bundle size, connectivity, spacing, and orientation are regulated by myosin activity. We conclude that myosin drives actomyosin bundle production and that myosin activity is tightly regulated during ovulation to produce an optimally organized actomyosin network in C. elegans spermathecae.

scholarly journals Caenorhabditis elegans as an in vivo Model to Assess Amphetamine Tolerance

2021 ◽  
pp. 1-9
Author(s):  
Dayana Torres Valladares ◽  
Sirisha Kudumala ◽  
Murad Hossain ◽  
Lucia Carvelli
Keyword(s):  
Caenorhabditis Elegans ◽  
Molecular Mechanisms ◽  
Drugs Of Abuse ◽  
Genetic Model ◽  
In Vivo Model ◽  
C Elegans ◽  
Hyperactivity Disorder ◽  
In Vitro Data

Amphetamine is a potent psychostimulant also used to treat attention deficit/hyperactivity disorder and narcolepsy. In vivo and in vitro data have demonstrated that amphetamine increases the amount of extra synaptic dopamine by both inhibiting reuptake and promoting efflux of dopamine through the dopamine transporter. Previous studies have shown that chronic use of amphetamine causes tolerance to the drug. Thus, since the molecular mechanisms underlying tolerance to amphetamine are still unknown, an animal model to identify the neurochemical mechanisms associated with drug tolerance is greatly needed. Here we took advantage of a unique behavior caused by amphetamine in <i>Caenorhabditis elegans</i> to investigate whether this simple, but powerful, genetic model develops tolerance following repeated exposure to amphetamine. We found that at least 3 treatments with 0.5 mM amphetamine were necessary to see a reduction in the amphetamine-induced behavior and, thus, to promote tolerance. Moreover, we found that, after intervals of 60/90 minutes between treatments, animals were more likely to exhibit tolerance than animals that underwent 10-minute intervals between treatments. Taken together, our results show that <i>C. elegans</i> is a suitable system to study tolerance to drugs of abuse such as amphetamines.

Transfer and tissue-specific accumulation of components in embryos of Caenorhabditis elegans and dolichura: in vivo analysis with a low-cost signal

Development ◽  
1992 ◽  
Vol 114 (2) ◽  
pp. 317-330 ◽  
Author(s):  
O. Bossinger ◽  
E. Schierenberg
Keyword(s):  
Caenorhabditis Elegans ◽  
Low Cost ◽  
Free Living ◽  
Tissue Specific ◽  
C Elegans ◽  
Specific Accumulation ◽  
In Vivo Analysis

The pattern of autofluorescence in the two free-living namatodes Rhabditis dolichura and Caenorhabditis compared. In C. elegans, during later embryogenesis cells develop a typical bluish autofluorescence as illumination, while in Rh. dolichura a strong already present in the unfertilized egg. Using a new,

scholarly journals Edible Flowers of Tagetes erecta L. as Functional Ingredients: Phenolic Composition, Antioxidant and Protective Effects on Caenorhabditis elegans

Nutrients ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 2002 ◽  
Author(s):  
Cristina Moliner ◽  
Lillian Barros ◽  
Maria Dias ◽  
Víctor López ◽  
Elisa Langa ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
In Vivo Model ◽  
Tagetes Erecta ◽  
Protective Effects ◽  
Phenolic Composition ◽  
C Elegans ◽  
Amyloid Toxicity ◽  
Phenolic Profiles ◽  
Tagetes Erecta L

Tagetes erecta L. has long been consumed for culinary and medicinal purposes in different countries. The aim of this study was to explore the potential benefits from two cultivars of T. erecta related to its polyphenolic profile as well as antioxidant and anti-aging properties. The phenolic composition was analyzed by LC-DAD-ESI/MSn. Folin-Ciocalteu, DPPH·, and FRAP assays were performed in order to evaluate reducing antiradical properties. The neuroprotective potential was evaluated using the enzymes acetylcholinesterase and monoamine oxidase. Caenorhabditis elegans was used as an in vivo model to assess extract toxicity, antioxidant activity, delayed aging, and reduced β-amyloid toxicity. Both extracts showed similar phenolic profiles and bioactivities. The main polyphenols found were laricitin and its glycosides. No acute toxicity was detected for extracts in the C. elegans model. T. erecta flower extracts showed promising antioxidant and neuroprotective properties in the different tested models. Hence, these results may add some information supporting the possibilities of using these plants as functional foods and/or as nutraceutical ingredients.

scholarly journals Forces drive basement membrane invasion inCaenorhabditis elegans

2018 ◽  
Vol 115 (45) ◽  
pp. 11537-11542 ◽  
Author(s):  
Rodrigo Cáceres ◽  
Nagagireesh Bojanala ◽  
Laura C. Kelley ◽  
Jes Dreier ◽  
John Manzi ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Basement Membrane ◽  
Actin Filaments ◽  
Actin Polymerization ◽  
Force Production ◽  
Developmental Event ◽  
C Elegans ◽  
Anchor Cell

During invasion, cells breach basement membrane (BM) barriers with actin-rich protrusions. It remains unclear, however, whether actin polymerization applies pushing forces to help break through BM, or whether actin filaments play a passive role as scaffolding for targeting invasive machinery. Here, using the developmental event of anchor cell (AC) invasion inCaenorhabditis elegans, we observe that the AC deforms the BM and underlying tissue just before invasion, exerting forces in the tens of nanonewtons range. Deformation is driven by actin polymerization nucleated by the Arp2/3 complex and its activators, whereas formins and cross-linkers are dispensable. Delays in invasion upon actin regulator loss are not caused by defects in AC polarity, trafficking, or secretion, as appropriate markers are correctly localized in the AC even when actin is reduced and invasion is disrupted. Overall force production emerges from this study as one of the main tools that invading cells use to promote BM disruption inC. elegans.

scholarly journals Identification of gmhA, a Yersinia pestis Gene Required for Flea Blockage, by Using a Caenorhabditis elegans Biofilm System

2005 ◽  
Vol 73 (11) ◽  
pp. 7236-7242 ◽  
Author(s):  
Creg Darby ◽  
Sandya L. Ananth ◽  
Li Tan ◽  
B. Joseph Hinnebusch
Keyword(s):  
Caenorhabditis Elegans ◽  
Yersinia Pestis ◽  
Biofilm Formation ◽  
Yersinia Pseudotuberculosis ◽  
C Elegans ◽  
Transposon Insertion ◽  
Insertion Mutants ◽  
Random Screening

ABSTRACT Yersinia pestis, the cause of bubonic plague, blocks feeding by its vector, the flea. Recent evidence indicates that blockage is mediated by an in vivo biofilm. Y. pestis and the closely related Yersinia pseudotuberculosis also make biofilms on the cuticle of the nematode Caenorhabditis elegans, which block this laboratory animal's feeding. Random screening of Y. pseudotuberculosis transposon insertion mutants with a C. elegans biofilm assay identified gmhA as a gene required for normal biofilms. gmhA encodes phosphoheptose isomerase, an enzyme required for synthesis of heptose, a conserved component of lipopolysaccharide and lipooligosaccharide. A Y. pestis gmhA mutant was constructed and was severely defective for C. elegans biofilm formation and for flea blockage but only moderately defective in an in vitro biofilm assay. These results validate use of the C. elegans biofilm system to identify genes and pathways involved in Y. pestis flea blockage.

scholarly journals Smooth muscle: a stiff sculptor of epithelial shapes

2018 ◽  
Vol 373 (1759) ◽  
pp. 20170318 ◽  
Author(s):  
Jacob M. Jaslove ◽  
Celeste M. Nelson
Keyword(s):  
Smooth Muscle ◽  
Embryonic Development ◽  
Cell Types ◽  
Myoepithelial Cells ◽  
Muscle Stiffness ◽  
Epithelial Morphogenesis ◽  
Functional Markers ◽  
Epithelial Layer ◽  
Mesenchymal Tissue

Smooth muscle is increasingly recognized as a key mechanical sculptor of epithelia during embryonic development. Smooth muscle is a mesenchymal tissue that surrounds the epithelia of organs including the gut, blood vessels, lungs, bladder, ureter, uterus, oviduct and epididymis. Smooth muscle is stiffer than its adjacent epithelium and often serves its morphogenetic function by physically constraining the growth of a proliferating epithelial layer. This constraint leads to mechanical instabilities and epithelial morphogenesis through buckling. Smooth muscle stiffness alone, without smooth muscle cell shortening, seems to be sufficient to drive epithelial morphogenesis. Fully understanding the development of organs that use smooth muscle stiffness as a driver of morphogenesis requires investigating how smooth muscle develops, a key aspect of which is distinguishing smooth muscle-like tissues from one another in vivo and in culture. This necessitates a comprehensive appreciation of the genetic, anatomical and functional markers that are used to distinguish the different subtypes of smooth muscle (for example, vascular versus visceral) from similar cell types (including myofibroblasts and myoepithelial cells). Here, we review how smooth muscle acts as a mechanical driver of morphogenesis and discuss ways of identifying smooth muscle, which is critical for understanding these morphogenetic events. This article is part of the Theo Murphy meeting issue ‘Mechanics of Development’.

scholarly journals Rosemary Flowers as Edible Plant Foods: Phenolic Composition and Antioxidant Properties in Caenorhabditis elegans

Antioxidants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 811
Author(s):  
Cristina Moliner ◽  
Víctor López ◽  
Lillian Barros ◽  
Maria Inês Dias ◽  
Isabel C. F. R. Ferreira ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Antioxidant Properties ◽  
Ethanolic Extract ◽  
Food Ingredient ◽  
Edible Plant ◽  
Phenolic Profile ◽  
C Elegans ◽  
Rosmarinus Officinalis L

Rosmarinus officinalis L., commonly known as rosemary, has been largely studied for its wide use as food ingredient and medicinal plant; less attention has been given to its edible flowers, being necessary to evaluate their potential as functional foods or nutraceuticals. To achieve that, the phenolic profile of the ethanolic extract of R. officinalis flowers was determined using LC-DAD-ESI/MSn and then its antioxidant and anti-ageing potential was studied through in vitro and in vivo assays using Caenorhabditis elegans. The phenolic content was 14.3 ± 0.1 mg/g extract, trans rosmarinic acid being the predominant compound in the extract, which also exhibited a strong antioxidant capacity in vitro and increased the survival rate of C. elegans exposed to lethal oxidative stress. Moreover, R. officinalis flowers extended C. elegans lifespan up to 18%. Therefore, these findings support the potential use of R. officinalis flowers as ingredients to develop products with pharmaceutical and/or nutraceutical potential.

scholarly journals In vivo analysis of FANCD2 recruitment at meiotic DNA breaks in Caenorhabditis elegans

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Marcello Germoglio ◽  
Anna Valenti ◽  
Ines Gallo ◽  
Chiara Forenza ◽  
Pamela Santonicola ◽  
...  
Keyword(s):  
Dna Repair ◽  
Caenorhabditis Elegans ◽  
Genome Stability ◽  
Genetic Interaction ◽  
Model Systems ◽  
Dna Breaks ◽  
Strand Breaks ◽  
C Elegans ◽  
In Vivo Analysis

AbstractFanconi Anemia is a rare genetic disease associated with DNA repair defects, congenital abnormalities and infertility. Most of FA pathway is evolutionary conserved, allowing dissection and mechanistic studies in simpler model systems such as Caenorhabditis elegans. In the present study, we employed C. elegans to better understand the role of FA group D2 (FANCD2) protein in vivo, a key player in promoting genome stability. We report that localization of FCD-2/FANCD2 is dynamic during meiotic prophase I and requires its heterodimeric partner FNCI-1/FANCI. Strikingly, we found that FCD-2 recruitment depends on SPO-11-induced double-strand breaks (DSBs) but not RAD-51-mediated strand invasion. Furthermore, exposure to DNA damage-inducing agents boosts FCD-2 recruitment on the chromatin. Finally, analysis of genetic interaction between FCD-2 and BRC-1 (the C. elegans orthologue of mammalian BRCA1) supports a role for these proteins in different DSB repair pathways. Collectively, we showed a direct involvement of FCD-2 at DSBs and speculate on its function in driving meiotic DNA repair.

scholarly journals A functional study of all 40 Caenorhabditis elegans insulin-like peptides

2018 ◽  
Vol 293 (43) ◽  
pp. 16912-16922 ◽  
Author(s):  
Shanqing Zheng ◽  
Hilton Chiu ◽  
Jeffrey Boudreau ◽  
Tony Papanicolaou ◽  
William Bendena ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Life Span ◽  
Peptide Ligands ◽  
Peptide Sequence ◽  
Functional Study ◽  
C Elegans ◽  
Multiple Phenotypes ◽  
Dauer Formation ◽  
Pleiotropic Function

The human genome encodes 10 insulin-like genes, whereas the Caenorhabditis elegans genome remarkably encodes 40 insulin-like genes. Knockout strategies to determine the roles of all the insulin/insulin-like peptide ligands (INS) in C. elegans has been challenging due to functional redundancy. Here, we individually overexpressed each of the 40 ins genes pan-neuronally, and monitored multiple phenotypes including: L1 arrest life span, neuroblast divisions under L1 arrest, dauer formation, and fat accumulation, as readouts to characterize the functions of each INS in vivo. Of the 40 INS peptides, we found functions for 35 INS peptides and functionally categorized each as agonists, antagonists, or of pleiotropic function. In particular, we found that 9 of 16 agonistic INS peptides shortened L1 arrest life span and promoted neuroblast divisions during L1 arrest. Our study revealed that a subset of β-class INS peptides that contain a distinct F peptide sequence are agonists. Our work is the first to categorize the structures of INS peptides and relate these structures to the functions of all 40 INS peptides in vivo. Our findings will promote the study of insulin function on development, metabolism, and aging-related diseases.

scholarly journals Combining single-cell RNA-sequencing with a molecular atlas unveils new markers for Caenorhabditis elegans neuron classes

2020 ◽  
Author(s):  
Ramiro Lorenzo ◽  
Michiho Onizuka ◽  
Matthieu Defrance ◽  
Patrick Laurent
Keyword(s):  
Caenorhabditis Elegans ◽  
Single Cell ◽  
Rna Sequencing ◽  
Cell Fate ◽  
Single Neuron ◽  
Genetic Manipulations ◽  
C Elegans ◽  
Single Cell Rna Sequencing ◽  
Normal Differentiation

Abstract Single-cell RNA-sequencing (scRNA-seq) of the Caenorhabditis elegans nervous system offers the unique opportunity to obtain a partial expression profile for each neuron within a known connectome. Building on recent scRNA-seq data and on a molecular atlas describing the expression pattern of ∼800 genes at the single cell resolution, we designed an iterative clustering analysis aiming to match each cell-cluster to the ∼100 anatomically defined neuron classes of C. elegans. This heuristic approach successfully assigned 97 of the 118 neuron classes to a cluster. Sixty two clusters were assigned to a single neuron class and 15 clusters grouped neuron classes sharing close molecular signatures. Pseudotime analysis revealed a maturation process occurring in some neurons (e.g. PDA) during the L2 stage. Based on the molecular profiles of all identified neurons, we predicted cell fate regulators and experimentally validated unc-86 for the normal differentiation of RMG neurons. Furthermore, we observed that different classes of genes functionally diversify sensory neurons, interneurons and motorneurons. Finally, we designed 15 new neuron class-specific promoters validated in vivo. Amongst them, 10 represent the only specific promoter reported to this day, expanding the list of neurons amenable to genetic manipulations.

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