A transcriptomic analysis of the adult stage of the bovine lungworm, Dictyocaulus viviparus

Shoba Ranganathan,Min Hu,Christina Strube,Robin B Gasser,Shivashankar H Nagaraj,Thomas Schnieder

doi:10.1186/1471-2164-8-311

Abstract

BackgroundLungworms of the genus Dictyocaulus (family Dictyocaulidae) are parasitic nematodes of major economic importance. They cause pathological effects and clinical disease in various ruminant hosts, particularly in young animals. Dictyocaulus viviparus, called the bovine lungworm, is a major pathogen of cattle, with severe infections being fatal. In this study, we provide first insights into the transcriptome of the adult stage of D. viviparus through the analysis of expressed sequence tags (ESTs).ResultsUsing our EST analysis pipeline, we estimate that the present dataset of 4436 ESTs is derived from 2258 genes based on cluster and comparative genomic analyses of the ESTs. Of the 2258 representative ESTs, 1159 (51.3%) had homologues in the free-living nematode C. elegans, 1174 (51.9%) in parasitic nematodes, 827 (36.6%) in organisms other than nematodes, and 863 (38%) had no significant match to any sequence in the current databases. Of the C. elegans homologues, 569 had observed 'non-wildtype' RNAi phenotypes, including embryonic lethality, maternal sterility, sterility in progeny, larval arrest and slow growth. We could functionally classify 776 (35%) sequences using the Gene Ontologies (GO) and established pathway associations to 696 (31%) sequences in Kyoto Encyclopedia of Genes and Genomes (KEGG). In addition, we predicted 85 secreted proteins which could represent potential candidates for developing novel anthelmintics or vaccines.ConclusionThe bioinformatic analyses of ESTs data for D. viviparus has elucidated sets of relatively conserved and potentially novel genes. The genes discovered in this study should assist research toward a better understanding of the basic molecular biology of D. viviparus, which could lead, in the longer term, to novel intervention strategies. The characterization of the D. viviparus transcriptome also provides a foundation for whole genome sequence analysis and future comparative transcriptomic analyses.

Highlights

Lungworms of the genus Dictyocaulus are parasitic nematodes of major economic importance
We provide a first insight into the transcriptome of the adult stage of D. viviparus via expressed sequence tags (ESTs) sequencing and apply a newly established computational platform [13] for the clustering and comparative analyses of the data set against data available for a range of organisms, with an emphasis on the best characterized nematode, C. elegans
These pre-processed ESTs ranged from 80–1164 bp, with a mean of 730 bp and a standard deviation (S.D.) of 258 bp

Summary

Introduction

Lungworms of the genus Dictyocaulus (family Dictyocaulidae) are parasitic nematodes of major economic importance. They cause pathological effects and clinical disease in various ruminant hosts, in young animals. Dictyocaulus viviparus, called the bovine lungworm, is a major pathogen of cattle, with severe infections being fatal. Lungworms of the genus Dictyocaulus (family Dictyocaulidae) are key parasitic nematodes which cause pathological effects and clinical disease in different ruminant hosts, in young animals [4,5]. Dictyocaulus viviparus, the bovine lungworm, causes a severe and frequently fatal bronchitis (known colloquially as 'husk') which is of major importance in many countries [6]. The period from ingestion of L3s to reproductive maturity of the adult worms is 3–4 weeks

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Conclusion