scholarly journals A Transcription Factor DAF5 Functions in Haemonchus Contortus Development

2021 ◽  
Author(s):  
Wenda Di ◽  
Fangfang Li ◽  
Li He ◽  
Chunqun Wang ◽  
Caixian Zhou ◽  
...  
Keyword(s):  
Haemonchus Contortus ◽  
Developmental Stages ◽  
Reproductive Organs ◽  
Bimolecular Fluorescence Complementation ◽  
Parasitic Nematodes ◽  
C Elegans ◽  
Free Living Nematode ◽  
And Function ◽  
Reproductive Processes

Abstract Background: Daf5 (Dauer abnormal formation gene), located in the downstream of DAF-7 signalling pathway, mainly functions in dauer formation and reproductive processes in the free-living nematode Caenorhabditis elegans. Although its structure and function have been studied clearly in C. elegans, it was totally unknown in Haemonchus contortus, a socio-economically important parasitic nematode of gastric ruminants.Methods: Here, we identified and characterized a homologue of Daf5, Hcdaf5 and its inferred product (HcDAF5) in H. contortus. Using an integrated molecular approach, we studied the transcriptional profiles of Hcdaf5 and the anatomical expression of HcDAF5 in H. contortus. RNA interference (RNAi) was performed to explore its function in transition from the exsheathed third-stage larvae (xL3) to the fourth-stage larvae (L4) in vitro. Interaction of HcDAF5 and HcDAF3 (a co-SMAD) was also detected by bimolecular fluorescence complementation system (BiFc) in vitro.Results: Here, we showed that HcDAF5 is a member of the Sno/Ski superfamily. Hcdaf5 was transcribed in all developmental stages of H. contortus, with a significant up-regulation in L3. Immunohistochemistry localized native HcDAF5 to the reproductive organs, cuticle and intestine. RNAi revealed specific siRNAs (small interfering RNA) could retard the xL3 development. In addition, the interaction between HcDAF5 and HcDAF3 indicated the SDS box region of HcDAF5 is dispensable for the binding of HcDAF5 to HcDAF3 and the region in HcDAF3 that binds to HcDAF5 is MH2 domain.Conclusion: In summary, these findings show that Hcdaf5 functions in developmental processes of H. contortus, and this is the first characterization of daf-5 gene in parasitic nematodes.

scholarly journals A transcription factor DAF-5 functions in Haemonchus contortus development

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Wenda Di ◽  
Fangfang Li ◽  
Li He ◽  
Chunqun Wang ◽  
Caixian Zhou ◽  
...  
Keyword(s):  
Haemonchus Contortus ◽  
Developmental Stages ◽  
Reproductive Organs ◽  
Bimolecular Fluorescence Complementation ◽  
Parasitic Nematodes ◽  
Small Interfering Rnas ◽  
C Elegans ◽  
Dauer Formation ◽  
And Function

Abstract Background Abnormal dauer formation gene (daf-5), located downstream of the DAF-7 signalling pathway, mainly functions in dauer formation and reproductive processes in the free-living nematode Caenorhabditis elegans. Although the structure and function of daf-5 have been clarified in C. elegans, they still remain totally unknown in Haemonchus contortus, a socio-economically important parasitic nematode of gastric ruminants. Methods A homologue of daf-5, Hc-daf-5, and its inferred product (Hc-DAF-5) in H. contortus were identified and characterized in this study. Then the transcriptional profiles of Hc-daf-5 and the anatomical expression of Hc-DAF-5 in H. contortus were studied using an integrated molecular approach. RNA interference (RNAi) was performed to explore its function in transition from the exsheathed third-stage larvae (xL3s) to the fourth-stage larvae (L4s) in vitro. Finally, the interaction between Hc-DAF-5 and Hc-DAF-3 (a co-Smad) was detected by bimolecular fluorescence complementation (BiFc) in vitro. Results It was shown that Hc-DAF-5 was a member of the Sno/Ski superfamily. Hc-daf-5 was transcribed in all developmental stages of H. contortus, with significant upregulation in L3s. Native Hc-DAF-5 was localized in the reproductive organs, cuticle, and intestine via immunohistochemistry. RNAi revealed that specific small interfering RNAs (siRNAs) could retard xL3 development. In addition, the interaction between Hc-DAF-5 and Hc-DAF-3 indicated that the SDS box of Hc-DAF-5 was dispensable for the binding of Hc-DAF-5 to Hc-DAF-3, and the MH2 domain was the binding region between Hc-DAF-3 and Hc-DAF-5. Conclusions In summary, these findings show that Hc-daf-5 functions in the developmental processes of H. contortus, and this study is the first attempt to characterize the daf-5 gene in parasitic nematodes. Graphical abstract

scholarly journals A DAF-3 co-Smad molecule functions in Haemonchus contortus development

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Wenda Di ◽  
Lu Liu ◽  
Ting Zhang ◽  
Fangfang Li ◽  
Li He ◽  
...  
Keyword(s):  
Haemonchus Contortus ◽  
Developmental Stages ◽  
Parasitic Nematodes ◽  
Evolutionary Patterns ◽  
Smad Proteins ◽  
Third Stage ◽  
Dauer Formation ◽  
And Function ◽  
Reproductive Processes

Abstract Background The Smad proteins function in TGF-β signalling transduction. In the model nematode Caenorhabditis elegans, the co-Smad, DAF-3 mediates R-Smads and performs a central role in DAF-7 signal transduction, regulating dauer formation and reproductive processes. Considering the divergent evolutionary patterns of the DAF-7 signalling pathway in parasitic nematodes, it is meaningful to explore the structure and function of DAF-3 in parasitic nematodes, such as Haemonchus contortus. Methods A daf-3 gene (Hc-daf-3) and its predicted product (Hc-DAF-3) were identified from H. contortus and characterised using integrated genomic and genetic approaches. In addition to immunohistochemistry employed to localise Hc-DAF-3 within adult worm sections, real-time PCR was conducted to assess the transcriptional profiles in different developmental stages of H. contortus and RNA interference (RNAi) was performed in vitro to assess the functional importance of Hc-daf-3 in the development of H. contortus. Results Hc-DAF-3 sequences predicted from Hc-daf-3 displayed typical features of the co-Smad subfamily. The native Hc-DAF-3 was localised to the gonad and cuticle of adult parasites. In addition, Hc-daf-3 was transcribed in all developmental stages studied, with a higher level in the third-stage larvae (L3) and adult females. Moreover, silencing Hc-daf-3 by RNAi retarded L4 development. Conclusion The findings of the present study demonstrated an important role of Hc-DAF-3 in the development of H. contortus larvae.

Nematode ligand-gated chloride channels: an appraisal of their involvement in macrocyclic lactone resistance and prospects for developing molecular markers

Parasitology ◽  
2007 ◽  
Vol 134 (8) ◽  
pp. 1111-1121 ◽  
Author(s):  
S. McCAVERA ◽  
T. K. WALSH ◽  
A. J. WOLSTENHOLME
Keyword(s):  
Haemonchus Contortus ◽  
Chloride Channels ◽  
Macrocyclic Lactone ◽  
Parasitic Nematodes ◽  
C Elegans ◽  
Molecular Tests ◽  
Cooperia Oncophora ◽  
Macrocyclic Lactone Resistance ◽  
High Level ◽  
Laboratory Models

SUMMARYLigand-gated chloride channels, including the glutamate-(GluCl) and GABA-gated channels, are the targets of the macrocyclic lactone (ML) family of anthelmintics. Changes in the sequence and expression of these channels can cause resistance to the ML in laboratory models, such as Caenorhabditis elegans and Drosophila melanogaster. Mutations in multiple GluCl subunit genes are required for high-level ML resistance in C. elegans, and this can be influenced by additional mutations in gap junction and amphid genes. Parasitic nematodes have a different complement of channel subunit genes from C. elegans, but a few genes, including avr-14, are widely present. A polymorphism in an avr-14 orthologue, which makes the subunit less sensitive to ivermectin and glutamate, has been identified in Cooperia oncophora, and polymorphisms in several subunits have been reported from resistant isolates of Haemonchus contortus. This has led to suggestions that ML resistance may be polygenic. Possible reasons for this, and its consequences for the development of molecular tests for resistance, are explored.

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.

scholarly journals Natural variation in Caenorhabditis elegans responses to the anthelmintic emodepside

2021 ◽  
Author(s):  
Janneke Wit ◽  
Steffen R. Hahnel ◽  
Briana C. Rodriguez ◽  
Erik Andersen
Keyword(s):  
Caenorhabditis Elegans ◽  
Mode Of Action ◽  
Natural Variation ◽  
Treatment Strategies ◽  
Parasitic Nematodes ◽  
Anthelmintic Drug ◽  
C Elegans ◽  
Hormetic Effect ◽  
Filarial Nematodes

Treatment of parasitic nematode infections depends primarily on the use of anthelmintics. However, this drug arsenal is limited, and resistance against most anthelmintics is widespread. Emodepside is a new anthelmintic drug effective against gastrointestinal and filarial nematodes. Nematodes that are resistant to other anthelmintic drug classes are susceptible to emodepside, indicating that the emodepside mode of action is distinct from previous anthelmintics. The laboratory-adapted Caenorhabditis elegans strain N2 is sensitive to emodepside, and genetic selection and in vitro experiments implicated slo-1, a BK potassium channel gene, in emodepside mode of action. In an effort to understand how natural populations will respond to emodepside, we measured brood sizes and developmental rates of wild C. elegans strains after exposure to the drug and found natural variation across the species. Some variation in emodepside responses can be explained by natural differences in slo-1. This result suggests that other genes in addition to slo-1 underlie emodepside resistance in wild C. elegans strains. Additionally, all assayed strains have higher offspring production in low concentrations of emodepside (a hormetic effect), which could impact treatment strategies. We find that natural variation affects emodepside sensitivity, supporting the suitability of C. elegans as a model system to study emodepside responses across parasitic nematodes.

scholarly journals In Vitro Efficacy of Aqueous and Methanol Extract of Cassia siamea Against the Motility of Caenorhabditis elegans

2020 ◽  
Vol 31 (3) ◽  
pp. 145-159
Author(s):  
Haladu Ali Gagman ◽  
Nik Ahmad Irwan Izzauddin Nik Him ◽  
Hamdan Ahmad ◽  
Shaida Fariza Sulaiman ◽  
Rahmad Zakaria ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Methanol Extract ◽  
Anthelmintic Resistance ◽  
Gastrointestinal Nematode ◽  
Parasitic Nematodes ◽  
Cassia Siamea ◽  
Methanol Extracts ◽  
C Elegans ◽  
Significant Difference

Gastrointestinal nematode infections can cause great losses in revenue due to decrease livestock production and animal death. The use of anthelmintic to control gastrointestinal nematode put a selection pressure on nematode populations which led to emergence of anthelmintic resistance. Because of that, this study was carried out to investigate the efficacy of aqueous and methanol extract of Cassia siamea against the motility of C. elegans Bristol N2 and C. elegans DA1316. Caenorhabditis elegans Bristol N2 is a susceptible strain and C. elegans DA1316 is an ivermectin resistant strain. In vitro bioassay of various concentrations of (0.2, 0.6, 0.8, 1.0 and 2.0 mg mL–1) aqueous and methanol extracts of C. siamea was conducted against the motility of L4 larvae of C. elegans Bristol N2 and C. elegans DA1316. The L4 larvae were treated with 0.02 μg mL–1 of ivermectin served as positive control while those in M9 solution served as negative control. The activity of the extracts was observed after 24 h and 48 h. A significant difference was recorded in the extract performance compared to control at (P < 0.001) after 48 h against the motility of the larvae of both strains. The methanol extracts inhibited the motility of C. elegans Bristol N2 by 86.7% as well as DA1316 up to 84.9% at 2.0 mg mL–1 after 48 h. The methanol extract was more efficient than aqueous extract (P < 0.05) against the motility of both strains of C. elegans. Cassia siamea may be used as a natural source of lead compounds for the development of alternative anthelmintic against parasitic nematodes as well ivermectin resistant strains of nematodes.

scholarly journals A novel BR-SMAD is required for larval development in barber’s pole worm Haemonchus contortus

2021 ◽  
Vol 8 (2) ◽  
pp. 57-64
Author(s):  
Fangfang Li ◽  
Peixi Qin ◽  
Lisha Ye ◽  
Nishith Gupta ◽  
Min Hu
Keyword(s):  
Haemonchus Contortus ◽  
Developmental Stages ◽  
Small Ruminants ◽  
Bmp Signaling ◽  
Bimolecular Fluorescence Complementation ◽  
Blood Sucking ◽  
Morphogenetic Protein ◽  
Smad Proteins ◽  
Family Protein ◽  
Parasitic Worms

SMAD proteins mediate TGF-β signaling and thereby regulate the metazoan development; however, they are poorly defined in Haemonchus contortus–a common blood-sucking parasitic nematode of small ruminants. Here, we characterized an R-SMAD family protein in H. contortus termed HcSMA2, which is closely related to Caenorhabditis elegans SMA2 (CeSMA2) involved in the bone morphogenetic protein (BMP) signaling. Hcsma2 is transcribed in all developmental stages of H. contortus but highly induced in the adult male worms. The RNA interference with Hcsma2 retarded the transition of infective L3 into L4 larvae. Besides, the bimolecular fluorescence complementation revealed the interaction of HcSMA2 with a TGF-β-activated-R-SMAD (HcDAF8). Together these results show a BMP-like receptor-regulated SMAD in H. contortus that is required for larval differentiation and underscore an adaptive functional repurposing of BMP-signaling in parasitic worms.

scholarly journals Small RNAs in parasitic nematodes – forms and functions

Parasitology ◽  
2019 ◽  
Vol 147 (8) ◽  
pp. 855-864
Author(s):  
Collette Britton ◽  
Roz Laing ◽  
Eileen Devaney
Keyword(s):  
Gene Expression ◽  
Small Rna ◽  
Small Rnas ◽  
Target Genes ◽  
Parasitic Nematodes ◽  
Small Rna Sequencing ◽  
Small Interfering Rnas ◽  
Rna Sequences ◽  
C Elegans

AbstractSmall RNAs are important regulators of gene expression. They were first identified in Caenorhabditis elegans, but it is now apparent that the main small RNA silencing pathways are functionally conserved across diverse organisms. Availability of genome data for an increasing number of parasitic nematodes has enabled bioinformatic identification of small RNA sequences. Expression of these in different lifecycle stages is revealed by small RNA sequencing and microarray analysis. In this review we describe what is known of the three main small RNA classes in parasitic nematodes – microRNAs (miRNAs), Piwi-interacting RNAs (piRNAs) and small interfering RNAs (siRNAs) – and their proposed functions. miRNAs regulate development in C. elegans and the temporal expression of parasitic nematode miRNAs suggest modulation of target gene levels as parasites develop within the host. miRNAs are also present in extracellular vesicles released by nematodes in vitro, and in plasma from infected hosts, suggesting potential regulation of host gene expression. Roles of piRNAs and siRNAs in suppressing target genes, including transposable elements, are also reviewed. Recent successes in RNAi-mediated gene silencing, and application of small RNA inhibitors and mimics will continue to advance understanding of small RNA functions within the parasite and at the host–parasite interface.

scholarly journals Comparison of two in vitro methods for the detection of ivermectin resistance in Haemonchus contortus in sheep

2016 ◽  
Vol 53 (2) ◽  
pp. 120-125 ◽  
Author(s):  
M. Urda Dolinská ◽  
A. Königová ◽  
M. Babják ◽  
M. Várady
Keyword(s):  
Drug Resistance ◽  
Haemonchus Contortus ◽  
Anthelmintic Resistance ◽  
Economic Losses ◽  
Parasitic Nematodes ◽  
Migration Inhibition ◽  
In Vitro Methods ◽  
Parasitic Helminths

SummaryGastrointestinal parasitic nematodes in sheep cause severe economic losses. Anthelmintics are the most commonly used drugs for prophylaxis and therapy against parasitic helminths. The problem of drug resistance has developed for all commercially available anthelmintics in several genera and classes of helminths. In vitro and in vivo tests are used to detect anthelmintic resistance. Two in vitro methods (larval migration inhibition test and micromotility test) for the detection of ivermectin (IVM) resistance were compared using IVM-resistant and IVM-susceptible isolates of Haemonchus contortus. The degree of resistance for each test was expressed as a resistance factor (RF). The micromotility test was more sensitive for quantitatively measuring the degree of resistance between susceptible and resistant isolates. The RFs for this test for IVM and eprinomectin ranged from 1.00 to 108.05 and from 3.87 to 32.32, respectively.

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