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.

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 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 Genome-Wide Identification of CircRNAs of Infective Larvae and Adult Worms of Parasitic Nematode, Haemonchus contortus

2021 ◽  
Vol 11 ◽  
Author(s):  
Caixian Zhou ◽  
Yao Zhang ◽  
Simin Wu ◽  
Zhiheng Wang ◽  
Waresi Tuersong ◽  
...  
Keyword(s):  
Haemonchus Contortus ◽  
Parasitic Nematode ◽  
Developmental Stages ◽  
Enrichment Analysis ◽  
Mapk Signaling ◽  
Differentially Expressed ◽  
Parasitic Nematodes ◽  
Transcriptional Level ◽  
Blood Sucking ◽  
Third Stage

CircRNAs, a novel class of ncRNA family, are endogenous transcriptional products involved in various biological and physiological processes in plants and animals. However, almost no information is available for circRNAs of parasitic helminths. In the present study, the circRNAs repertoire was comprehensively explored in Haemonchus contortus, a blood-sucking parasitic nematode of ruminants. In total, 20073 circRNAs were identified and annotated from three key developmental stages/genders of H. contortus including the free-living infective third-stage larvae (L3, 18883), parasitic adult female (Af, 3491), and male worms (Am, 2550) via deep-sequencing technology and bioinformatic analysis. Among these identified circRNAs, 71% were derived from exonic regions of protein-coding genes. The number of circRNAs transcribed from the X chromosome (4704) was higher than that from Chromosome I-V (3143, 3273, 3041, 3030, 2882). The amount of highly expressed circRNAs in third-stage larvae was significantly more abundant than that in adult stage. 15948 and 16847 circRNAs were differentially expressed between Af and L3s and between Am and L3, respectively. Among them, 13409 circRNAs existed in both comparisons. Furthermore, 1119 circRNAs were differentially expressed between Af_and_Am. GO enrichment analysis indicated that source genes of circRNAs differentially expressed between Am and L3 as well as between Af and L3 were significantly enriched in many biological processes, primarily including signaling, signal transduction and cell communication terms. KEGG analysis revealed that parental genes of differentially expressed circRNAs were mainly related to metabolism (pyruvate metabolism, glycerophospholipid metabolism, and carbon metabolism), MAPK signaling pathway, and phosphatidylinositol signaling system. Moreover, many circRNAs contained one or more miRNA potential binding sites, suggesting that they could regulate gene expression at the post-transcriptional level. Furthermore, the correctness of head-to-tail back splicing site and alternative circularization events were verified by Sanger sequencing using both divergent and convergent primers. Finally, the reliability of RNA-Seq data and the resistance of circRNAs to RNase R digestion were confirmed by quantitative RT-PCR. Taken together, our findings provide a foundation for elucidating the regulatory mechanisms of circRNAs in H. contortus, which will advance the understanding of circRNAs in parasitic nematodes.

The nematode-trapping efficacy of two chlamydospore-forming fungi against Haemonchus contortus in sheep

2005 ◽  
Vol 79 (4) ◽  
pp. 315-319 ◽  
Author(s):  
J.B. Chauhan ◽  
P.K. Sanyal ◽  
R.B. Subramanian
Keyword(s):  
Biological Control ◽  
Haemonchus Contortus ◽  
Antagonistic Effect ◽  
Parasitic Nematodes ◽  
Duddingtonia Flagrans ◽  
Infective Larvae ◽  
Third Stage ◽  
Indian Isolates ◽  
Set Up

AbstractAn in vitro study was carried out to determine efficacy of Indian isolates of the nematode-trapping fungi Arthrobotrys musiformis and Duddingtonia flagrans to capture infective larvae of Haemonchus contortus. These fungi have previously been screened and selected for their survival in the gastrointestinal tract of sheep without losing growth and nematode capturing potential. Following the feeding of chlamydospores of these two fungi alone or in combination in sheep experimentally infected with Haemonchus contortus, coprocultures were set up to enumerate the infective third stage larvae. The number of larvae captured from faeces of fungus-fed sheep was significantly higher compared with fungus-unfed controls irrespective of the fungus used. The fungal combination produced no antagonistic effect and thus can be used as efficiently as the fungi alone in the biological control of animal parasitic nematodes.

scholarly journals Susceptible trichostrongyloid species mask presence of benzimidazole-resistant Haemonchus contortus in cattle

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Khalid M. Mohammedsalih ◽  
Jürgen Krücken ◽  
Ahmed Bashar ◽  
Fathel-Rahman Juma ◽  
Abdalhakaim A. H. Abdalmalaik ◽  
...  
Keyword(s):  
Haemonchus Contortus ◽  
Epidemiological Data ◽  
Nematode Species ◽  
Parasitic Nematodes ◽  
Molecular Approaches ◽  
Tubulin Genes ◽  
Faecal Egg Count ◽  
Third Stage ◽  
Before And After ◽  
Β Tubulin

Abstract Background Benzimidazole (BZ) anthelmintics are widely used to control infections with parasitic nematodes, but BZ resistance is an emerging threat among several nematode species infecting humans and animals. In Sudan, BZ-resistant Haemonchus contortus populations were recently reported in goats in South Darfur State. The objective of this study was to collect data regarding the situation of BZ resistance in cattle parasitic nematodes in South Darfur using phenotypic and molecular approaches, besides providing some epidemiological data on nematodes in cattle. Methods The faecal egg count reduction test and the egg hatch test (EHT) were used to evaluate benzimidazole efficacy in cattle nematodes in five South Darfur study areas: Beleil, Kass, Nyala, Rehed Al-Birdi and Tulus. Genomic DNA was extracted from pools of third-stage larvae (L3) (n = 40) during trials, before and after treatment, and pools of adult male Haemonchus spp. (n = 18) from abattoirs. The polymorphisms F167Y, E198A and F200Y in isotype 1 β-tubulin genes of H. contortus and H. placei were analysed using Sanger and pyrosequencing. Results Prevalence of gastro-intestinal helminths in cattle was 71% (313/443). Reduced albendazole faecal egg count reduction efficacy was detected in three study areas: Nyala (93.7%), Rehed Al-Birdi (89.7%) and Tulus (88.2%). In the EHT, EC50 values of these study areas ranged between 0.032 and 0.037 µg/ml thiabendazole. Genus-specific PCRs detected the genera Haemonchus, Trichostrongylus and Cooperia in L3 samples collected after albendazole treatment. Sanger sequencing followed by pyrosequencing assays did not detect elevated frequencies of known BZ resistance-associated alleles in codon F167Y, E198A and F200Y in isotype 1 β-tubulin gene of H. placei (≤ 11.38%). However, polymorphisms were detected in H. contortus and in samples with mixed infections with H. contortus and H. placei at codon 198, including E198L (16/58), E198V (2/58) and potentially E198Stop (1/58). All pooled L3 samples post-albendazole treatment (n = 13) were identified as H. contortus with an E198L substitution at codon 198. Conclusions To the knowledge of the authors, this is the first report of reduced albendazole efficacy in cattle in Sudan and is the first study describing an E198L substitution in phenotypically BZ-resistant nematodes collected from cattle.

scholarly journals Effect of Five Mediterranean Shrubs Extracts on Larval Exsheathment of Haemonchus contortus

2021 ◽  
Author(s):  
A. Aïssa ◽  
F. Manolaraki ◽  
H. Ben Salem ◽  
H. Hoste ◽  
K. Kraiem
Keyword(s):  
Haemonchus Contortus ◽  
Small Ruminants ◽  
Good Alternative ◽  
Gastrointestinal Nematodes ◽  
Shrub Species ◽  
Medicago Arborea ◽  
Mediterranean Shrubs ◽  
Third Stage

Background: Mediterranean shrub species cover more than 70% of the total area in Tunisia and in summer when the herbaceous species have wilted, they constitute feeding resource for livestock. The use of tanniniferous shrubs seems to be a good alternative to control gastrointestinal nematodes infections in small ruminants. This study evaluated the in vitro anthelmintic (AH) effect of Ceratonia siliqua (C. siliqua), Periploca angustifolia Labill. (P. angustifolia) and Medicago arborea (M. arborea) against Haemonchus contortus third stage larvae (L3). Methods: The larval exsheathment assay (LEA) was used to determine the proportions (%) of exsheathment of five acetonic extracts at different concentrations (1200, 600, 300, 150 μg/ml). To confirm the role of tannins in the AH effects of extracts, polyvinyl polypyrolidone (PVPP) was used as deactivating chemical tannins. Result: The highest % L3 exsheathed was recorded for M. arborea (55.01%) and the lowest value was founded for C. siliqua and P. angustifolia leaves (16.26%). Our results were concentration-dependent (P less than 0.001). The % of exsheathment increased as the time of incubation increased (P less than 0.001). P. angustifolia pods recorded the lowest EC50 value (P less than 0.05). After PVPP addition, all the acetonic extracts showed a restoration of L3 exsheathment values similar to control values (P less than 0.001).

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 Natural Compounds from the Marine Brown Alga Caulocystis cephalornithos with Potent In Vitro-Activity against the Parasitic Nematode Haemonchus contortus

Pathogens ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 550
Author(s):  
Aya C. Taki ◽  
Robert Brkljača ◽  
Tao Wang ◽  
Anson V. Koehler ◽  
Guangxu Ma ◽  
...  
Keyword(s):  
Haemonchus Contortus ◽  
Brown Alga ◽  
Parasitic Nematode ◽  
Anthelmintic Activity ◽  
Adult Males ◽  
Terrestrial Plants ◽  
Third Stage ◽  
Future Work ◽  
Marine Brown Alga

Eight secondary metabolites (1 to 8) were isolated from a marine sponge, a marine alga and three terrestrial plants collected in Australia and subsequently chemically characterised. Here, these natural product-derived compounds were screened for in vitro-anthelmintic activity against the larvae and adult stages of Haemonchus contortus (barber’s pole worm)—a highly pathogenic parasitic nematode of ruminants. Using an optimised, whole-organism screening system, compounds were tested on exsheathed third-stage larvae (xL3s) and fourth-stage larvae (L4s). Anthelmintic activity was initially evaluated on these stages based on the inhibition of motility, development and/or changes in morphology (phenotype). We identified two compounds, 6-undecylsalicylic acid (3) and 6-tridecylsalicylic acid (4) isolated from the marine brown alga, Caulocystis cephalornithos, with inhibitory effects on xL3 and L4 motility and larval development, and the induction of a “skinny-straight” phenotype. Subsequent testing showed that these two compounds had an acute nematocidal effect (within 1–12 h) on adult males and females of H. contortus. Ultrastructural analysis of adult worms treated with compound 4 revealed significant damage to subcuticular musculature and associated tissues and cellular organelles including mitochondria. In conclusion, the present study has discovered two algal compounds possessing acute anthelmintic effects and with potential for hit-to-lead progression. Future work should focus on undertaking a structure-activity relationship study and on elucidating the mode(s) of action of optimised compounds.

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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