scholarly journals A SECOND CLASS OF ACETYLCHOLINESTERASE-DEFICIENT MUTANTS OF THE NEMATODE CAENORHABDITIS ELEGANS

Genetics ◽  
1981 ◽  
Vol 97 (2) ◽  
pp. 281-305 ◽  
Author(s):  
Joseph G Culotti ◽  
Gunter Von Ehrenstein ◽  
Marilyn R Culotti ◽  
Richard L Russell
Keyword(s):  
Caenorhabditis Elegans ◽  
Gene Dosage ◽  
Acetylcholinesterase Activity ◽  
Histochemical Staining ◽  
C Elegans ◽  
Recessive Mutations ◽  
Mutant Strains ◽  
Class B ◽  
Chromosome I ◽  
Longitudinal Nerve

ABSTRACT In Johnson et al. (1981), the Caenorhabditis elegans mutant strain PR1000, homozygous for the ace-1 mutation p1000, is shown to be deficient in the class A subset of acetylcholinesterases, which comprises approximately one-half of the total C. elegans acetylcholinesterase activity. Beginning with this strain, we have isolated 487 new behavioral and morphological mutant strains. Two of these, independently derived, lack approximately 98% of the wild-type acetylcholinesterase activity and share the same specific uncoordinated phenotype; both move forward in a slow and uncoordinated manner, and when mechanically stimulated to induce reversal, both hypercontract and become temporarily paralyzed. In addition to the ace-1 mutation, both strains also harbor recessive mutations in the same newly identified gene, ace-2, which maps to chromosome I and is therefore not linked to ace-1. Gene dosage experiments suggest that ace-2 is a structural gene for the remaining class B acetylcholinesterases, which are not affected by ace-1. —The uncoordinated phenotype of the newly isolated, doubly mutant strains depends on both the ace-1 and ace-2 mutations; homozygosity for either mutation alone produces normally coordinated animals. This result implies functional overlap of the acetylcholinesterases controlled by ace-1 and ace-2, perhaps at common synapses. Consistent with this, light microscopic histochemical staining of permeabilized whole mounts indicates some areas of possible spatial overlap of these acetylcholinesterases (nerve ring, longitudinal nerve cords). In addition, there is at least one area where only ace-2-controlled acetylcholinesterase activity appears (pharyngeo-intestinal valve).

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.

scholarly journals Astragalus Polysaccharide Suppresses 6-Hydroxydopamine-Induced Neurotoxicity in Caenorhabditis elegans

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Haifeng Li ◽  
Ruona Shi ◽  
Fei Ding ◽  
Hongyu Wang ◽  
Wenjing Han ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Caenorhabditis Elegans ◽  
Protective Effect ◽  
Therapeutic Potential ◽  
Neuroprotective Effect ◽  
Acetylcholinesterase Activity ◽  
Apoptosis Pathway ◽  
Acidic Polysaccharide ◽  
C Elegans ◽  
6 Hydroxydopamine

Astragalus membranaceus is a medicinal plant traditionally used in China for a variety of conditions, including inflammatory and neural diseases. Astragalus polysaccharides are shown to reduce the adverse effect of levodopa which is used to treat Parkinson’s disease (PD). However, the neuroprotective effect of Astragalus polysaccharides per se in PD is lacking. Using Caenorhabditis elegans models, we investigated the protective effect of astragalan, an acidic polysaccharide isolated from A. membranaceus, against the neurotoxicity of 6-hydroxydopamine (6-OHDA), a neurotoxin that can induce parkinsonism. We show that 6-OHDA is able to degenerate dopaminergic neurons and lead to the deficiency of food-sensing behavior and a shorter lifespan in C. elegans. Interestingly, these degenerative symptoms can be attenuated by astragalan treatment. Astragalan is also shown to alleviate oxidative stress through reducing reactive oxygen species level and malondialdehyde content and increasing superoxide dismutase and glutathione peroxidase activities and reduce the expression of proapoptotic gene egl-1 in 6-OHDA-intoxicated nematodes. Further studies reveal that astragalan is capable of elevating the decreased acetylcholinesterase activity induced by 6-OHDA. Together, our results demonstrate that the protective effect of astragalan against 6-OHDA neurotoxicity is likely due to the alleviation of oxidative stress and regulation of apoptosis pathway and cholinergic system and thus provide an important insight into the therapeutic potential of Astragalus polysaccharide in neurodegeneration.

scholarly journals Assessment of the In Vivo Antioxidant Activity of an Anthocyanin-Rich Bilberry Extract Using the Caenorhabditis elegans Model

Antioxidants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 509
Author(s):  
Ana M. González-Paramás ◽  
Virginia Brighenti ◽  
Laura Bertoni ◽  
Laura Marcelloni ◽  
Begoña Ayuda-Durán ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Caenorhabditis Elegans ◽  
Biological Effects ◽  
In Vivo Model ◽  
Heat Shock Factor 1 ◽  
Formation Factor ◽  
C Elegans ◽  
Mutant Strains ◽  
Bilberry Extract

Anthocyanins have been associated with several health benefits, although the responsible mechanisms are not well established yet. In the present study, an anthocyanin-rich extract from bilberry (Vaccinium myrtillus L.) was tested in order to evaluate its capacity to modulate reactive oxygen species (ROS) production and resistance to thermally induced oxidative stress, using the nematode Caenorhabditis elegans as an in vivo model. The assays were carried out with the wild-type N2 strain and the mutant strains daf-16(mu86) I and hsf-1(sy441), which were grown in the presence of two anthocyanin extract concentrations (5 and 10 μg/mL in the culture medium) and further subjected to thermal stress. The treatment with the anthocyanin extract at 5 μg/mL showed protective effects on the accumulation of ROS and increased thermal resistance in C. elegans, both in stressed and non-stressed young and aged worms. However, detrimental effects were observed in nematodes treated with 10 μg/mL, leading to a higher worm mortality rate compared to controls, which was interpreted as a hormetic response. These findings suggested that the effects of the bilberry extract on C. elegans might not rely on its direct antioxidant capacity, but other mechanisms could also be involved. Additional assays were performed in two mutant strains with loss-of-function for DAF-16 (abnormal DAuer Formation factor 16) and HSF-1 (Heat Shock Factor 1) transcription factors, which act downstream of the insulin/insulin like growth factor-1 (IGF-1) signaling pathway. The results indicated that the modulation of these factors could be behind the improvement in the resistance against thermal stress produced by bilberry anthocyanins in young individuals, whereas they do not totally explain the effects produced in worms in the post-reproductive development stage. Further experiments are needed to continue uncovering the mechanisms behind the biological effects of anthocyanins in living organisms, as well as to establish whether they fall within the hormesis concept.

scholarly journals Gengnianchun Extends the Lifespan of Caenorhabditis elegans via the Insulin/IGF-1 Signalling Pathway

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Fanhui Meng ◽  
Jun Li ◽  
Yanqiu Rao ◽  
Wenjun Wang ◽  
Yan Fu
Keyword(s):  
Thermal Stress ◽  
Caenorhabditis Elegans ◽  
Chinese Medicine ◽  
Stress Resistance ◽  
Antioxidant Properties ◽  
Signalling Pathway ◽  
Rna Seq ◽  
C Elegans ◽  
Beneficial Effects ◽  
Mutant Strains

Gengnianchun (GNC), a traditional Chinese medicine (TCM), is believed to have beneficial effects on ageing-related diseases, such as antioxidant properties and effects against Aβ-induced toxicity. We previously found that GNC extended the lifespan of Caenorhabditis elegans. However, the mechanism underlying this effect was unclear. In this study, we further explored the mechanisms of GNC using a C. elegans model. GNC significantly increased the lifespan of C. elegans and enhanced oxidative and thermal stress resistance. Moreover, chemotaxis increased after GNC treatment. RNA-seq analysis showed that GNC regulated genes associated with longevity. We also conducted lifespan assays with a series of worm mutants. The results showed that GNC significantly extended the lifespan of several mutant strains, including eat-2 (ad465), rsks-1 (ok1255), and glp-1 (e2144), suggesting that the prolongevity effect of GNC is independent of the function of these genes. However, GNC failed to extend the lifespan of daf-2 (e1370), age-1 (hx546), and daf-16 (mu86) mutant strains. Our findings suggest that GNC extends the lifespan of C. elegans via the insulin/IGF-1 signalling pathway and may be a potential antiageing agent.

Three Mutants That Extend Both Mean and Maximum Life Span of the Nematode, Caenorhabditis elegans , Define the age-1 Gene

2002 ◽  
Vol 2002 (38) ◽  
Author(s):  
David B. Friedman ◽  
Thomas E. Johnson
Keyword(s):  
Caenorhabditis Elegans ◽  
Life Span ◽  
Pleiotropic Effect ◽  
Wild Type ◽  
Nematode Caenorhabditis Elegans ◽  
Maximum Life Span ◽  
Gerontological Society ◽  
Recessive Mutations ◽  
Mutant Strains ◽  
Independent Mutation

Long-lived mutants in the nematode Caenorhabditis elegans have been studied to determine if the mutations responsible for extended life were allelic. Three of four mutant strains studied (MK31, MK542, MK546) contain recessive mutations that significantly lengthen life; MK542 and MK546 consistently fail to complement the long life phenotype of age-1 and are therefore allelic. MK31, although longer lived than wild type, is equivocal, in some cases failing to complement age-1 but not in others. All three long-lived strains have reduced hermaphrodite self-fertility and also fail to complement for this presumed pleiotropic effect of the age-1 mutation. Each of these three strains also contains an independent mutation at unc-31 IV. Since the mutants were isolated in the same mutant hunt (Klass, 1983) using protocols that did not guarantee independence, the mutations cannot be assumed to be independently isolated. Copyright (c) The Gerontological Society of America. Reproduced by permission of the publisher. David B. Friedman, Thomas E. Johnson, Three Mutants That Extend Both Mean and Maximum Life Span of the Nematode, Caenorhabditis elegans , Define the age-1 Gene. J. Gerontol. 43 , B102-B109 (1988).

‘Promoter trapping’ in Caenorhabditis elegans

Development ◽  
1991 ◽  
Vol 113 (2) ◽  
pp. 399-408 ◽  
Author(s):  
I.A. Hope
Keyword(s):  
Caenorhabditis Elegans ◽  
Expression Patterns ◽  
Cell Types ◽  
Histochemical Staining ◽  
Lacz Gene ◽  
Dna Fragments ◽  
C Elegans ◽  
Active Expression ◽  
Beta Galactosidase

A screen of gene expression patterns has been developed for the nematode Caenorhabditis elegans. Promoter-reporter gene fusions were constructed in vitro by ligating C. elegans genomic DNA fragments upstream of a lacZ gene. Patterns of beta-galactosidase expression were examined by histochemical staining of C. elegans lines transformed with the constructs. beta-galactosidase expression depended on translational fusion, so constructs were assayed in large pools to expedite detection of the low proportion that were active. Expression in a variety of cell types and temporal patterns was observed with different construct pools. The most striking expression patterns were obtained when the beta-galactosidase activity was localized to subcellular structures by the C. elegans portion of the fusion protein. The active constructs of three selected pools were identified subsequently by an efficient combinatorial procedure. The genomic locations of the DNA fragments from the active constructs were determined and appear to define previously uncharacterized genetic loci.

RNA interference and protein expression of the four calmodulin-like genes in Caenorhabditis elegans

Biologia ◽  
2015 ◽  
Vol 70 (6) ◽  
Author(s):  
Anton Karabinos
Keyword(s):  
Caenorhabditis Elegans ◽  
Calcium Binding ◽  
The Body ◽  
Rnai Phenotype ◽  
C Elegans ◽  
Embryonic Lethal ◽  
Ef Hand ◽  
Mutant Strains ◽  
Significant Expression ◽  
High Throughput Study

AbstractCalmodulin (CaM) is a major intracellular calcium receptor and probably the best studied member of the EF hand family of eukaryotic calcium-binding proteins. In contrast, much less is known about the related CaM-like proteins in animals and plants. We have previously characterized an embryonic phenotype of the single CaM gene cmd-1 from the nematode Caenorhabditis elegans. A previous functional high throughput study in C. elegans reported an embryonic lethal RNAi phenotype also for the related CaM-like gene cal-2. Based on these results we aimed to analyse the reported embryonic lethal cal-2 RNAi phenotype and compare it to that of the CaM cmd-1 embryo. Unfortunately, we were not able to find any visible RNAi phenotype for cal-2 as well as for the three remaining nematode cal genes cal-1, cal-3 and cal-4. However, because CaMs often have long cellular half-lives, we think that a definitive picture about the functionality of these genes will be established once corresponding mutant strains will be available. Immunofluorescence analyses revealed a significant expression of the CAL-2 and CAL-4 proteins in the body wall muscle indicating a possible functional redundancy of both these proteins in the C. elegans muscle.

scholarly journals Comparative phytochemical analysis of Phlogacanthus thyrsiflorus Nees: Implications on attenuation of pro-oxidants and pathogen virulence in Caenorhabditis elegans model system

2017 ◽  
Vol 10 (5) ◽  
pp. 361
Author(s):  
Kitlangki Suchiang ◽  
Nitasha H Kayde
Keyword(s):  
Oxidative Stress ◽  
Free Radicals ◽  
Free Radical ◽  
Caenorhabditis Elegans ◽  
Model System ◽  
Wild Type ◽  
C Elegans ◽  
Mutant Strains

Background: Phlogacanthus thyrsiflorus Nees (P. thyrsiflorus) of Acanthaceae family is endogenous to sub-tropical Himalayas. It has been reported to be used traditionally in Jaintia tribe of Meghalaya, India for treatment of many ailments.Objectives: The aim was to detect the active compounds present in the leaves for evaluation of in vitro free radicals scavenging potentials. Leaves protective actions in vivo will be investigated using Caenorhabditis elegans (C. elegans) model system utilizing wild type and mutant strains and the phenomena of host-pathogens interactions.Materials and methods: Gas chromatography/ Mass spectrometry (GC/MS) was used for detection of different compounds present. The versatility of leaf extracts to scavenge different free radicals generated in vitro was assessed with different in vitro methods. Survival analysis of wild type and mutant strains C. elegans under enhanced pro-oxidants exposure was investigated in vivo. Fast killing assay was also performed to study the extracts modulatory activity on host C. elegans survival under pathogen Pseudomonas aeruginosa infection.Results:  Forty compounds were detected in methanolic fraction of the extract with variable percentages. Both aqueous and methanol extract possessed remarkable, versatile free radical scavenging activity irrespective of the types of free radical generated. The in vivo experiments are in compliance, with observable increased survival ability percentage of C. elegans under intense exogenous oxidative stress and pathogen infection.Conclusion: Our findings enlightened the different compounds present with versatility of P. thyrsiflorus in tackling different free radicals generated both in vitro and in vivo that highly support for its candidature as a good antioxidant source. Our findings may justify the historical relevance of this plant in herbal remedies that could form the basis for inquiry of new active principles.Keywords: Free radicals, Oxidative stress, Caenorhabditis elegans, Phlogacanthus thyrsiflorus, Phytochemicals

scholarly journals AN ACETYLCHOLINESTERASE-DEFICIENT MUTANT OF THE NEMATODE CAENORHABDITIS ELEGANS

Genetics ◽  
1981 ◽  
Vol 97 (2) ◽  
pp. 261-279 ◽  
Author(s):  
Carl D Johnson ◽  
John G Duckett ◽  
Joseph G Culotti ◽  
Robert K Herman ◽  
Philip M Meneely ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Gene Dosage ◽  
Sodium Deoxycholate ◽  
Molecular Forms ◽  
Kinetic Properties ◽  
Wild Type ◽  
Nematode Caenorhabditis Elegans ◽  
Class A ◽  
Mutant Strains ◽  
The Right

ABSTRACT Within a set of five separable molecular forms of acetylcholinesterase found in the nematode Caenorhabditis elegans, previously reported differences in kinetic properties identify two classes, A and B, likely to be under separate genetic control. Using differences between these classes in sensitivity to inactivation by sodium deoxycholate, a screening procedure was devised to search for mutants affected only in class A forms. Among 171 previously isolated behavioral and morphological mutant strains examined by this procedure, one (PR946) proved to be of the expected type, exhibiting a selective deficiency of class A acetylcholinesterase forms. Although originally isolated because of its uncoordinated behavior, this strain was subsequently shown to harbor mutations in two genes; one in the previously identified gene unc-3, accounting for its behavior, and one in a newly identified gene, ace-1, accounting for its selective acetylcholinesterase deficiency. Derivatives homozygous only for the ace-1 mutation also lacked class A acetylcholinesterase forms, but were behaviorally and developmentally indistinguishable from wild type. The gene ace-1 has been mapped near the right end of the X chromosome. Gene dosage experiments suggest that it may be a structural gene for a component of class A acetylcholinesterase forms.

scholarly journals Production of null mutants in the major intestinal esterase gene (ges-1) of the nematode Caenorhabditis elegans.

Genetics ◽  
1990 ◽  
Vol 125 (3) ◽  
pp. 505-514 ◽  
Author(s):  
J D McGhee ◽  
J C Birchall ◽  
M A Chung ◽  
D A Cottrell ◽  
L G Edgar ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Isoelectric Focusing ◽  
Esterase Activity ◽  
Histochemical Staining ◽  
Wild Type ◽  
Nematode Caenorhabditis Elegans ◽  
Obvious Effect ◽  
C Elegans ◽  
Esterase Inhibitors ◽  
Esterase Gene

Abstract The ges-1 gene of the nematode Caenorhabditis elegans codes for a nonspecific carboxylesterase that is expressed only in the intestinal lineage. This esterase has turned out to be a convenient biochemical marker for lineage-specific differentiation. In the present paper, we describe the production of several C. elegans strains that lack detectable activity of the ges-1 esterase. To isolate these ges-1 null strains, we first produced a strain of hermaphrodites in which the wild-type copy of the ges-1 gene was stably balanced over a previously isolated isoelectric focusing allele, ges-1(ca6); this parental strain was then mutagenized with EMS and isoelectric focusing gels were used to identify progeny populations that lacked either ges-1(+) or ges-1(ca6) esterase activity. This method is a straightforward and general approach to obtaining null mutations in any gene that has a biochemical or immunological assay. The ges-1 gene is not essential to worm survival, development or reproduction. Furthermore, lack of the ges-1 product has no obvious effect on the ability of worms (containing either normal or greatly reduced levels of acetylcholinesterases) to survive exposure to esterase inhibitors. The ges-1 gene product provides roughly half of the total esterase activity measured in crude extracts of L1 larvae or mixed worm populations. However, histochemical staining of individual ges-1(0) embryos shows that the ges-1 esterase is the first and essentially the only esterase to be produced during embryonic development, from the midproliferation phase up to at least the twofold stage of morphogenesis. These ges-1(0) strains now allow us to investigate the developmental control of the ges-1 gene by DNA-mediated transformation, in which the ges-1 gene acts as its own reporter.

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