Identification and preliminary characterization of Hc-clec-160, a novel C-type lectin domain-containing gene of the strongylid nematode Haemonchus contortus

Ling Zhang,Xueqiu Chen,Yi Yang,Min Hu,Aifang Du,Xing-Quan Zhu,Xiangrui Li,Lingyun Mou,Xun Suo

doi:10.1186/s13071-018-3005-3

Abstract

BackgroundThe strongylid parasite Haemonchus contortus causes severe anemia in domestic animals worldwide. Effective preventive and therapeutical agents are lacking, because of drug resistance and that little is known about the molecular mechanism of the interaction between H. contortus and host cells.MethodsA new gene, Hc-clec-160, was discovered with RT-PCR. Transcriptional levels of Hc-clec-160 and Ce-clec-160 throughout different growth phases of corresponding nematodes were assayed by qPCR. Immunofluorescence staining of paraffin section were performed to determine the protein localization in adult worms of H. contortus. To monitor the promoter capacity of the 5'-flanking region of Ce-clec-160, micro-injection was used. Overexpression and RNAi constructs was carried out in the N2 strain of Caenorhabditis elegans to find out the gene function of Hc-clec-160.ResultsThe full-length cDNA of 1224 bp of Hc-clec-160 was cloned by RT-PCR. The corresponding gene contained twelve exons. Its transcripts peaked in male adult worms. Hc-CLEC-160 was predicted to have a Willebrand factor type A (vWA) domain and a C-type lectin domain. The proteins were not detected by expression in C. elegans or paraffin section experiments in adult of H. contortus. Knockdown of Ce-clec-160 expression in C. elegans by RNAi resulted in shortened body length and decreased brood size.ConclusionsIn this experiment, a new gene Hc-clec-160 was obtained in H. contortus and its function was addressed using a model organism: C. elegans. Our study showed that Hc-clec-160 possesses characteristics similar to those of Ce-clec-160 and plays an important role in the growth and reproduction of this parasitic nematode.

Highlights

The strongylid parasite Haemonchus contortus causes severe anemia in domestic animals worldwide
We identified and characterized a novel gene of Hc-clec-160 in H. contortus, which is an ortholog of C. elegans and possesses one CTL domain (CTLD)
Hc-clec-160 of H. contortus contained 12 exons separated by 11 introns, which was structurally similar to Ce-clec-160 of C. elegans

Summary

Introduction

The strongylid parasite Haemonchus contortus causes severe anemia in domestic animals worldwide. C-type lectin (CTL) is a Ca2+-dependent glycan-binding protein (GBP) that shares primary and secondary structural homology in its carbohydrate-recognition domain (CRD). Zhang et al Parasites & Vectors (2018) 11:430 protein C [1, 2]. They often oligomerize, which increases their avidity for multivalent ligands. Some CTLs are exocrine whereas others are transmembrane proteins They play a role in adhesion and signaling receptors in many pathways, including homeostasis and innate immunity, and are crucial in inflammatory responses and leukocyte and platelet trafficking. It is difficult to predict the glycan structures that bind to a particular CTL due to the relatively shallow CRD of CTL with few contacts to sugars motifs

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Conclusion