scholarly journals Microbial byproducts determine reproductive fitness of free-living and parasitic nematodes

2021 ◽  
Author(s):  
Mericien Venzon ◽  
Ritika Das ◽  
Daniel J. Luciano ◽  
Hyun Shin Park ◽  
Eric T. Kool ◽  
...  
Keyword(s):  
Fatty Acid Biosynthesis ◽  
Reproductive Fitness ◽  
Parasitic Nematodes ◽  
Free Living ◽  
Trichuris Muris ◽  
E Coli ◽  
C Elegans ◽  
Evolutionarily Conserved ◽  
Gnotobiotic Mice ◽  
Mammalian Intestine

Trichuris nematodes reproduce within the microbiota-rich mammalian intestine, yet microbial byproducts that facilitate the parasite lifecycle are unknown. Here, we report a novel pipeline to identify microbial factors with conserved roles in the reproduction of nematodes. A screen for E. coli mutants that impair C. elegans fertility identified genes in fatty acid biosynthesis and ethanolamine utilization pathways, including fabH and eutN. Trichuris muris eggs displayed defective hatching in the presence of E. coli deficient in fabH or eutN due to reduction in arginine or elevated levels of aldehydes, respectively. Remarkably, T. muris reared in gnotobiotic mice colonized with these E. coli mutants failed to lay viable eggs. These findings indicate that microbial byproducts mediate evolutionarily conserved transkingdom interactions that impact reproductive fitness of distantly-related nematodes.

scholarly journals The Ditylenchus destructor genome provides new insights into the evolution of plant parasitic nematodes

2016 ◽  
Vol 283 (1835) ◽  
pp. 20160942 ◽  
Author(s):  
Jinshui Zheng ◽  
Donghai Peng ◽  
Ling Chen ◽  
Hualin Liu ◽  
Feng Chen ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Evolutionary Process ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Free Living ◽  
C Elegans ◽  
Free Living Nematode ◽  
Plant Nematode ◽  
Ditylenchus Destructor ◽  
Plant Parasitic

Plant-parasitic nematodes were found in 4 of the 12 clades of phylum Nematoda. These nematodes in different clades may have originated independently from their free-living fungivorous ancestors. However, the exact evolutionary process of these parasites is unclear. Here, we sequenced the genome sequence of a migratory plant nematode, Ditylenchus destructor . We performed comparative genomics among the free-living nematode, Caenorhabditis elegans and all the plant nematodes with genome sequences available. We found that, compared with C. elegans , the core developmental control processes underwent heavy reduction, though most signal transduction pathways were conserved. We also found D. destructor contained more homologies of the key genes in the above processes than the other plant nematodes. We suggest that Ditylenchus spp. may be an intermediate evolutionary history stage from free-living nematodes that feed on fungi to obligate plant-parasitic nematodes. Based on the facts that D. destructor can feed on fungi and has a relatively short life cycle, and that it has similar features to both C. elegans and sedentary plant-parasitic nematodes from clade 12, we propose it as a new model to study the biology, biocontrol of plant nematodes and the interaction between nematodes and plants.

The use of Caenorhabditis elegans in parasitic nematode research

Parasitology ◽  
2004 ◽  
Vol 128 (S1) ◽  
pp. S49-S70 ◽  
Author(s):  
J. S. GILLEARD
Keyword(s):  
Caenorhabditis Elegans ◽  
Parasitic Nematode ◽  
Expression System ◽  
Nematode Species ◽  
Current Status ◽  
Evolutionary Development ◽  
Parasitic Nematodes ◽  
Free Living ◽  
C Elegans ◽  
Free Living Nematode

There is increasing interest in the use of the free-living nematode Caenorhabditis elegans as a tool for parasitic nematode research and there are now a number of compelling examples of its successful application. C. elegans has the potential to become a standard tool for molecular helminthology researchers, just as yeast is routinely used by molecular biologists to study vertebrate biology. However, in order to exploit C. elegans in a meaningful manner, we need a detailed understanding of the extent to which different aspects of C. elegans biology have been conserved with particular groups of parasitic nematodes. This review first considers the current state of knowledge regarding the conservation of genome organisation across the nematode phylum and then discusses some recent evolutionary development studies in free-living nematodes. The aim is to provide some important concepts that are relevant to the extrapolation of information from C. elegans to parasitic nematodes and also to the interpretation of experiments that use C. elegans as a surrogate expression system. In general, examples have been specifically chosen because they highlight the importance of careful experimentation and interpretation of data. Consequently, the focus is on the differences that have been found between nematode species rather than the similarities. Finally, there is a detailed discussion of the current status of C. elegans as a heterologous expression system to study parasite gene function and regulation using successful examples from the literature.

scholarly journals Microbial Byproducts Determine Reproductive Fitness of Free-Living and Parasitic Nematodes

2021 ◽  
Author(s):  
Mericien Venzon ◽  
Ritika Das ◽  
Daniel J. Luciano ◽  
Hyun Shin Park ◽  
Eric T. Kool ◽  
...  
Keyword(s):  
Reproductive Fitness ◽  
Parasitic Nematodes ◽  
Free Living

scholarly journals Attachment tests of Pasteuria penetrans to the cuticle of plant and animal parasitic nematodes, free living nematodes and srf mutants of Caenorhabditis elegans

1999 ◽  
Vol 73 (1) ◽  
pp. 67-71 ◽  
Author(s):  
P. Mendoza de Gives ◽  
K.G. Davies ◽  
M. Morgan ◽  
J.M. Behnke
Keyword(s):  
Caenorhabditis Elegans ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Pasteuria Penetrans ◽  
Cyst Nematodes ◽  
Free Living ◽  
Root Knot Nematodes ◽  
C Elegans ◽  
Spore Attachment ◽  
Plant Parasitic

Populations of Pasteuria penetrans isolated from root-knot nematodes (Meloidogyne spp.) and cyst nematodes (Heterodera spp.) were tested for their ability to adhere to a limited selection of sheathed and exsheathed animal parasitic nematodes, free living nematodes, including Caenorhabditis elegans wild type and several srf mutants, and plant parasitic nematodes. The attachment of spores of Pasteuria was restricted and no spores were observed adhering to any of the animal parasitic nematodes either with or without their sheath or to any of the free living nematodes including C. elegans and the srf mutants. All spore attachment was restricted to plant parasitic nematodes; however, spores isolated from cyst nematodes showed the ability to adhere to other genera of plant parasitic nematodes which was not the case with spores isolated from root-knot nematodes. The results are discussed in relationship to cuticular heterogeneity.

scholarly journals Curtisia dentata (Cornaceae) leaf extracts and isolated compounds inhibit motility of parasitic and free-living nematodes

2009 ◽  
Vol 76 (2) ◽  
Author(s):  
L.J. Shai ◽  
E.S. Bizimenyera ◽  
V. Bagla ◽  
L.J. McGaw ◽  
J.N. Eloff
Keyword(s):  
Medicinal Plant ◽  
Betulinic Acid ◽  
Small Ruminants ◽  
Anthelmintic Activity ◽  
Parasitic Nematodes ◽  
Leaf Extracts ◽  
Free Living ◽  
C Elegans

Haemonchus contortus and Trichostrongylus colubriformis are among the most important parasitic nematodes of small ruminants. Caenorhabditis elegans, a free-living nematode, is used as a model for evaluating anthelmintic activity of a variety of test substances. Extracts of several medicinal plants are useful in vitro and in vivo against nematode development. Extracts of Curtisia dentata, a South African medicinal plant, and compounds isolated from leaves of this plant were investigated for anthelmintic activity against T. colubriformis, H. contortus and C. elegans. The acetone and dichloromethane extracts were active against all nematodes at concentrations as low as 160 μg/mℓ. Betulinic acid and lupeol were active against the parasitic nematodes only at the high concentrations of 1 000 and 200 μg/mℓ, respectively. All compounds were effective against C. elegans with active concentrations as low as 8 μg/mℓ. Betulinic acid was less active than lupeol and ursolic acid against C. elegans. The acetone and dichloromethane extracts were also active against C. elegans with a concentration of 0.31 mg/mℓ resulting in almost 80 % inhibition of larval motility. The use of free-living nematodes may provide information on the activity of potential anthelmintics against parasitic nematodes. Extracts of various medicinal plant species may provide solutions to ill-health of small ruminants caused by parasitic nematodes in poor communities of southern Africa.

scholarly journals Caenorhabditis elegans: nature and nurture gift to nematode parasitologists

Parasitology ◽  
2017 ◽  
Vol 145 (8) ◽  
pp. 979-987 ◽  
Author(s):  
Gustavo Salinas ◽  
Gastón Risi
Keyword(s):  
Animal Model ◽  
Caenorhabditis Elegans ◽  
Parasitic Nematode ◽  
Model Organism ◽  
Parasitic Nematodes ◽  
Free Living ◽  
C Elegans ◽  
Free Living Nematode ◽  
Basic Biology ◽  
Nature And Nurture

AbstractThe free-living nematode Caenorhabditis elegans is the simplest animal model organism to work with. Substantial knowledge and tools have accumulated over 50 years of C. elegans research. The use of C. elegans relating to parasitic nematodes from a basic biology standpoint or an applied perspective has increased in recent years. The wealth of information gained on the model organism, the use of the powerful approaches and technologies that have advanced C. elegans research to parasitic nematodes and the enormous success of the omics fields have contributed to bridge the divide between C. elegans and parasite nematode researchers. We review key fields, such as genomics, drug discovery and genetics, where C. elegans and nematode parasite research have convened. We advocate the use of C. elegans as a model to study helminth metabolism, a neglected area ready to advance. How emerging technologies being used in C. elegans can pave the way for parasitic nematode research is discussed.

scholarly journals Plant-Based Natural Products for the Discovery and Development of Novel Anthelmintics against Nematodes

Biomolecules ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 426 ◽  
Author(s):  
Maoxuan Liu ◽  
Sujogya Kumar Panda ◽  
Walter Luyten
Keyword(s):  
Medicinal Plants ◽  
Mechanisms Of Action ◽  
Model System ◽  
Parasitic Nematodes ◽  
Great Promise ◽  
Botanical Origin ◽  
Free Living ◽  
C Elegans ◽  
Structure Activity ◽  
Free Living Nematode

Intestinal parasitic nematodes infect approximately two billion people worldwide. In the absence of vaccines for human intestinal nematodes, control of infections currently relies mainly on chemotherapy, but resistance is an increasing problem. Thus, there is an urgent need for the discovery and development of new anthelmintic drugs, especially ones with novel mechanisms of action. Medicinal plants hold great promise as a source of effective treatments, including anthelmintic therapy. They have been used traditionally for centuries and are mostly safe (if not, their toxicity is well-known). However, in most medicinal plants the compounds active against nematodes have not been identified thus far. The free-living nematode C. elegans was demonstrated to be an excellent model system for the discovery of new anthelmintics and for characterizing their mechanism of action or resistance. The compounds discussed in this review are of botanical origin and were published since 2002. Most of them need further studies of their toxicity, mechanisms and structure-activity relationship to assess more fully their potential as drugs.

scholarly journals The genome of Caenorhabditis bovis

2019 ◽  
Author(s):  
Lewis Stevens ◽  
Stefan Rooke ◽  
Laura C Falzon ◽  
Eunice M Machuka ◽  
Kelvin Momanyi ◽  
...  
Keyword(s):  
Draft Genome ◽  
Gene Families ◽  
Nematode Species ◽  
Laboratory Culture ◽  
Eastern Africa ◽  
Laboratory Model ◽  
Parasitic Nematodes ◽  
Zebu Cattle ◽  
Free Living ◽  
C Elegans

AbstractThe free-living nematode Caenorhabditis elegans is a key laboratory model for metazoan biology. C. elegans is also used as a model for parasitic nematodes despite being only distantly related to most parasitic species. All ∼65 Caenorhabditis species currently in culture are free-living with most having been isolated from decaying plant or fungal matter. Caenorhabditis bovis is a particularly unusual species, having been isolated several times from the inflamed ears of Zebu cattle in Eastern Africa where it is believed to be the cause of bovine parasitic otitis. C. bovis is therefore of particular interest to researchers interested in the evolution of nematode parasitism and in Caenorhabditis diversity. However, as C. bovis is not in laboratory culture, it remains little studied and details of its prevalence, role in bovine parasitic otitis and relationships to other Caenorhabditis species are scarce. Here, by sampling livestock markets and slaughterhouses in Western Kenya, we successfully reisolate C. bovis from the ear of adult female Zebu. We sequence the genome of C. bovis using the Oxford Nanopore MinION platform in a nearby field laboratory and use the data to generate a chromosome-scale draft genome sequence. We exploit this draft genome to reconstruct the phylogenetic relationships of C. bovis to other Caenorhabditis species and reveal the changes in genome size and content that have occurred during its evolution. We also identify expansions in several gene families that have been implicated in parasitism in other nematode species, including those associated with resistance to antihelminthic drugs. The high-quality draft genome and our analyses thereof represent a significant advancement in our understanding of this unusual Caenorhabditis species.

scholarly journals Bacillus thuringiensis DB27 Produces Two Novel Protoxins, Cry21Fa1 and Cry21Ha1, Which Act Synergistically against Nematodes

2014 ◽  
Vol 80 (10) ◽  
pp. 3266-3275 ◽  
Author(s):  
Igor Iatsenko ◽  
Iuliia Boichenko ◽  
Ralf J. Sommer
Keyword(s):  
Bacillus Thuringiensis ◽  
Virulence Factors ◽  
Insect Pests ◽  
Parasitic Nematodes ◽  
Intestinal Damage ◽  
High Similarity ◽  
Free Living ◽  
Cry Proteins ◽  
Content Type ◽  
C Elegans

ABSTRACTBacillus thuringiensishas been widely used as a biopesticide, primarily for the control of insect pests, but someB. thuringiensisstrains specifically target nematodes. However, nematicidal virulence factors ofB. thuringiensisare poorly investigated. Here, we describe virulence factors of nematicidalB. thuringiensisDB27 usingCaenorhabditis elegansas a model. We show thatB. thuringiensisDB27 kills a number of free-living and animal-parasitic nematodes via intestinal damage. Its virulence factors are plasmid-encoded Cry protoxins, since plasmid-cured derivatives do not produce Cry proteins and are not toxic to nematodes. Whole-genome sequencing ofB. thuringiensisDB27 revealed multiple potential nematicidal factors, including several Cry-like proteins encoded by different plasmids. Two of these proteins appear to be novel and show high similarity to Cry21Ba1. Named Cry21Fa1 and Cry21Ha1, they were expressed inEscherichia coliand fed toC. elegans, resulting in intoxication, intestinal damage, and death of nematodes. Interestingly, the effects of the two protoxins onC. elegansare synergistic (synergism factor, 1.8 to 2.5). Using purified proteins, we determined the 50% lethal concentrations (LC50s) for Cry21Fa1 and Cry21Ha1 to be 13.6 μg/ml and 23.9 μg/ml, respectively, which are comparable to the LC50of nematicidal Cry5B. Finally, we found that signaling pathways which protectC. elegansagainst Cry5B toxin are also required for protection against Cry21Fa1. Thus,B. thuringiensisDB27 produces novel nematicidal protoxins Cry21Fa1 and Cry21Ha1 with synergistic action, which highlights the importance of naturally isolated strains as a source of novel toxins.

scholarly journals The astacin metalloprotease moulting enzyme NAS-36 is required for normal cuticle ecdysis in free-living and parasitic nematodes

Parasitology ◽  
2010 ◽  
Vol 138 (2) ◽  
pp. 237-248 ◽  
Author(s):  
GILLIAN STEPEK ◽  
GILLIAN McCORMACK ◽  
ANDREW J. BIRNIE ◽  
ANTONY P. PAGE
Keyword(s):  
Direct Consequence ◽  
Gastrointestinal Nematode ◽  
Nematode Species ◽  
Parasitic Nematodes ◽  
Recombinant Enzymes ◽  
Free Living ◽  
C Elegans ◽  
Collagenous Matrix ◽  
Free Living Nematode ◽  
Similar Range

SUMMARYNematodes represent one of the most abundant and species-rich groups of animals on the planet, with parasitic species causing chronic, debilitating infections in both livestock and humans worldwide. The prevalence and success of the nematodes is a direct consequence of the exceptionally protective properties of their cuticle. The synthesis of this cuticle is a complex multi-step process, which is repeated 4 times from hatchling to adult and has been investigated in detail in the free-living nematode, Caenorhabditis elegans. This process is known as moulting and involves numerous enzymes in the synthesis and degradation of the collagenous matrix. The nas-36 and nas-37 genes in C. elegans encode functionally conserved enzymes of the astacin metalloprotease family which, when mutated, result in a phenotype associated with the late-stage moulting defects, namely the inability to remove the preceding cuticle. Extensive genome searches in the gastrointestinal nematode of sheep, Haemonchus contortus, and in the filarial nematode of humans, Brugia malayi, identified NAS-36 but not NAS-37 homologues†. Significantly, the nas-36 gene from B. malayi could successfully complement the moult defects associated with C. elegans nas-36, nas-37 and nas-36/nas-37 double mutants, suggesting a conserved function for NAS-36 between these diverse nematode species. This conservation between species was further indicated when the recombinant enzymes demonstrated a similar range of inhibitable metalloprotease activities.

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