Transcriptome sequencing and analysis of the zoonotic parasite Spirometra erinacei spargana (plerocercoids)

Abstract

BackgroundAlthough spargana, which are the plerocercoids of Spirometra erinacei, are of biological and clinical importance, expressed sequence tags (ESTs) from this parasite have not been explored. To understand molecular and biological features of this parasite, sparganum ESTs were examined by large-scale EST sequencing and multiple bioinformatics tools.MethodsTotal RNA was isolated from spargana and then ESTs were generated, assembled and sequenced. Many biological aspects of spargana were investigated using multi-step bioinformatics tools.ResultsA total of 5,634 ESTs were collected from spargana. After clustering and assembly, the functions of 1,794 Sparganum Assembled ESTs (SpAEs) including 934 contigs and 860 singletons were analyzed. A total of 1,351 (75%) SpAEs were annotated using a hybrid of BLASTX and InterProScan. Of these genes, 1,041 (58%) SpAEs had high similarity to tapeworms. In the context of the biology of sparganum, our analyses reveal: (i) a highly expressed fibronectin 1, a ubiquitous and abundant glycoprotein; (ii) up-regulation of enzymes related with glycolysis pathway; (iii) most frequent domains of protein kinase and RNA recognition motif domain; (iv) a set of helminth-parasitic and spargana-specific genes that may offer a number of antigen candidates.ConclusionsOur transcriptomic analysis of S. erinacei spargana demonstrates biological aspects of a parasite that invades and travels through subcutaneous tissue in intermediate hosts. Future studies should include comparative analyses using combinations of transcriptome and proteome data collected from the entire life cycle of S. erinacei.Electronic supplementary materialThe online version of this article (doi:10.1186/1756-3305-7-368) contains supplementary material, which is available to authorized users.

The genome of the sparganosis tapeworm Spirometra erinaceieuropaei isolated from the biopsy of a migrating brain lesion

“…Nine out of the 25 most frequently expressed Pfam domains reported in S. erinaceieuropaei EST data [20] are also present in the top expanded gene families that we have identified. Thus, expanded gene families (protein kinase, BTB/Kelch associated, EF hand, WD40 repeat, Kelch motif, fibronectin type III, zinc finger C2H2, AMP-dependent synthetase and dynein light chain) are also amongst the most expressed and therefore likely to be functionally important to the organism.…”

The genome of the sparganosis tapeworm Spirometra erinaceieuropaeiisolated from the biopsy of a migrating brain lesion

“…We used the genome to examine expanded gene families in S. erinaceieuropaei . Nine out of the 25 most frequently expressed Pfam domains reported in S. erinaceieuropaei EST data [ 20 ] are also present in the top expanded gene families that we have identified. Thus, expanded gene families (protein kinase, BTB/Kelch associated, EF hand, WD40 repeat, Kelch motif, fibronectin type III, zinc finger C2H2, AMP-dependent synthetase and dynein light chain) are also amongst the most expressed and therefore likely to be functionally important to the organism.…”

“…We interrogated the S. erinaceieuropaei genome with a recently published EST data set [ 20 ] and found that all 5,641 ESTs had a significant BLAST match with e-values of <1e-05, indicating that the genome contains useful molecular data. Additionally, we found that 73% of ESTs were within predicted gene models.…”

“…A reciprocal BLAST search confirmed that the latter gene is a likely orthologue of tub-2 , highly expressed in E. multilocularis larva. We also searched for β-tubulin transcripts by BLAST in recently published EST data from the larval stage of S. erinaceieuropaei [ 20 ], and found that of 26 β-tubulin ESTs, 24 contained the benzimidazole resistance-associated amino acids.…”

“…We reasoned that if the orthologue expression pattern is similar across species [ 45 ], then, as with E. multilocularis , benzimidazole would likely be suboptimal for chemotherapy against larval tapeworms of Spirometra . Using recently published EST data from the larva of S. erinaceieuropaei [ 20 ], we identified β-tubulin transcripts and found that the majority contained the benzimidazole resistance-associated amino acids.…”