title: Comparative genomics reveals Cyclospora cayetanensis possesses coccidia-like metabolism and invasion components but unique surface antigens.
abstract: Cyclospora cayetanensis is an apicomplexan that causes diarrhea in humans. The investigation of foodborne outbreaks of cyclosporiasis has been hampered by a lack of genetic data and poor understanding of pathogen biology. In this study we sequenced the genome of C. cayetanensis and inferred its metabolism and invasion components based on comparative genomic analysis.
  
  
  
  The genome organization, metabolic capabilities and potential invasion mechanism of C. cayetanensis are very similar to those of Eimeria tenella. Propanoyl-CoA degradation, GPI anchor biosynthesis, and N-glycosylation are some apparent metabolic differences between C. cayetanensis and E. tenella. Unlike Eimeria spp., there are no active LTR-retrotransposons identified in C. cayetanensis. The similar repertoire of host cell invasion-related proteins possessed by all coccidia suggests that C. cayetanensis has an invasion process similar to the one in T. gondii and E. tenella. However, the significant reduction in the number of identifiable rhoptry protein kinases, phosphatases and serine protease inhibitors indicates that monoxenous coccidia, especially C. cayetanensis, have limited capabilities or use a different system to regulate host cell nuclear activities. C. cayetanensis does not possess any cluster of genes encoding the TA4-type SAG surface antigens seen in E. tenella, and may use a different family of surface antigens in initial host cell interactions.
  
  
  
  Our findings indicate that C. cayetanensis possesses coccidia-like metabolism and invasion components but unique surface antigens. Amino acid metabolism and post-translation modifications of proteins are some major differences between C. cayetanensis and other apicomplexans. The whole genome sequence data of C. cayetanensis improve our understanding of the biology and evolution of this major foodborne pathogen and facilitate the development of intervention measures and advanced diagnostic tools.
authors.affiliation: State Key Laboratory of Bioreactor Engineering, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, China.|Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, 30333, USA.
authors.forename: Shiyou
authors.initials: S
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Bioreactor Engineering, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.affiliation: Shanghai-Ministry of Science and Technology Key Laboratory of Health and Disease Genomics, Chinese National Human Genome Center at Shanghai, 250 Bibo Road, Shanghai, 201203, China.
authors.forename: Huajun
authors.initials: H
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Bioreactor Engineering, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, China.
authors.forename: Zhixiao
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, 30333, USA.
authors.forename: Dawn M
authors.initials: DM
authors.lastname: Roellig
authors.affiliation: State Key Laboratory of Bioreactor Engineering, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, China.|Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, 30333, USA.
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.affiliation: Division of Scientific Resources, Centers for Disease Control and Prevention, Atlanta, GA, 30333, USA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Frace
authors.affiliation: Division of Scientific Resources, Centers for Disease Control and Prevention, Atlanta, GA, 30333, USA.
authors.forename: Kevin
authors.initials: K
authors.lastname: Tang
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, 30333, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Arrowood
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, 30333, USA.
authors.forename: Delynn M
authors.initials: DM
authors.lastname: Moss
authors.affiliation: College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450002, China.
authors.forename: Longxian
authors.initials: L
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Bioreactor Engineering, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, China. yyfeng@ecust.edu.cn.
authors.forename: Yaoyu
authors.initials: Y
authors.lastname: Feng
authors.affiliation: Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, 30333, USA. lxiao@cdc.gov.
authors.forename: Lihua
authors.initials: L
authors.lastname: Xiao
mesh_terms: D000953:Antigens, Protozoan / Q000276:immunology*; D015415:Biomarkers; D019295:Computational Biology / Q000379:methods; D021744:Cyclospora / Q000472:pathogenicity / Q000502:physiology*; D004734:Energy Metabolism / Q000235:genetics; D016678:Genome; D023281:Genomics / Q000379:methods; D059014:High-Throughput Nucleotide Sequencing; D053858:Metabolic Networks and Pathways; D058977:Molecular Sequence Annotation; D010802:Phylogeny
chemical_list: D000953:Antigens, Protozoan; D015415:Biomarkers
keywords: Apicomplexan; Cyclospora; Evolution; Genetics; Genome; Genomics