title: De novo transcriptome sequencing and analysis of the juvenile and adult stages of Fasciola gigantica.
abstract: Fasciola gigantica is regarded as the major liver fluke causing fasciolosis in livestock in tropical countries. Despite the significant economic and public health impacts of F. gigantica there are few studies on the pathogenesis of this parasite and our understanding is further limited by the lack of genome and transcriptome information. In this study, de novo Illumina RNA sequencing (RNA-seq) was performed to obtain a comprehensive transcriptome profile of the juvenile (42days post infection) and adult stages of F. gigantica. A total of 49,720 unigenes were produced from juvenile and adult stages of F. gigantica, with an average length of 1286 nucleotides (nt) and N50 of 2076nt. A total of 27,862 (56.03%) unigenes were annotated by BLAST similarity searches against the NCBI non-redundant protein database. Because F. gigantica needs to feed and/or digest host tissues, some proteases (including cysteine proteases and aspartic proteases), which play a role in the degradation of host tissues (protein), have been paid more attention in the present study. A total of 6511 distinct genes were found differentially expressed between juveniles and adults, of which 3993 genes were up-regulated and 2518 genes were down-regulated in adults versus juveniles, respectively. Moreover, stage-specific differentially expressed genes were identified in juvenile (17,009) and adult (6517) F. gigantica. The significantly divergent pathways of differentially expressed genes included cAMP signaling pathway (226; 4.12%), proteoglycans in cancer (256; 4.67%) and focal adhesion (199; 3.63%). The transcription pattern also revealed two egg-laying-associated pathways: cGMP-PKG signaling pathway and TGF-β signaling pathway. This study provides the first comparative transcriptomic data concerning juvenile and adult stages of F. gigantica that will be of great value for future research efforts into understanding parasite pathogenesis and developing vaccines against this important parasite.
authors.affiliation: College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin Province 130118, PR China; State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China.
authors.forename: Xiao-Xuan
authors.initials: XX
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China; College of Marine Science, Shandong University at Weihai, Weihai, Shandong Province 264209, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Cong
authors.affiliation: Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK.
authors.forename: Hany M
authors.initials: HM
authors.lastname: Elsheikha
authors.affiliation: College of Veterinary Medicine, Hunan Agricultural University, Changsha, Hunan Province 410128, PR China.
authors.forename: Guo-Hua
authors.initials: GH
authors.lastname: Liu
authors.affiliation: College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin Province 130118, PR China; State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China.
authors.forename: Jian-Gang
authors.initials: JG
authors.lastname: Ma
authors.affiliation: Department of Parasitology, College of Animal Science and Technology, Guangxi University, Nanning, Guangxi Zhuang Autonomous Region 530005, PR China.
authors.forename: Wei-Yi
authors.initials: WY
authors.lastname: Huang
authors.affiliation: College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin Province 130118, PR China. Electronic address: zhaoquan0825@163.com.
authors.forename: Quan
authors.initials: Q
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China; Jiangsu Co-innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University College of Veterinary Medicine, Yangzhou, Jiangsu Province 225009, PR China. Electronic address: xingquanzhu1@hotmail.com.
authors.forename: Xing-Quan
authors.initials: XQ
authors.lastname: Zhu
mesh_terms: D000818:Animals; D057055:Aspartic Acid Proteases / Q000145:classification / Q000235:genetics; D002020:Buffaloes; D057056:Cysteine Proteases / Q000145:classification / Q000235:genetics; D030541:Databases, Genetic; D005209:Fasciola / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D005211:Fascioliasis / Q000469:parasitology / Q000662:veterinary*; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D063990:Gene Ontology; D017238:Genes, Helminth; D015801:Helminth Proteins / Q000145:classification / Q000235:genetics*; D059014:High-Throughput Nucleotide Sequencing; D053858:Metabolic Networks and Pathways / Q000235:genetics*; D058977:Molecular Sequence Annotation; D015398:Signal Transduction; D059467:Transcriptome
chemical_list: D015801:Helminth Proteins; D057055:Aspartic Acid Proteases; D057056:Cysteine Proteases
keywords: De novo transcriptome; Differentially expressed genes; Fasciola gigantica; Host-pathogen interaction; Next-generation sequencing