title: Determination of the full-genome sequence of hepatitis E virus (HEV) SAAS-FX17 and use as a reference to identify putative HEV genotype 4 virulence determinants.
abstract: BACKGROUND
  Four major genotypes of hepatitis E virus (HEV), the causative agent of hepatitis E, have so far been recognized. While genotypes 3 and 4 are both zoonotic, the disease symptoms caused by the latter tend to be more severe. To examine if specific nucleotide/amino acid variations between genotypes 3 and 4 play a role in determining the severity of hepatitis E disease, the complete genome of one swine HEV genotype 4 isolate, SAAS-FX17, was determined and compared with other genotype 4 and genotype 3 genomes to identify putative HEV genotype 4 virulence determinants.
  
  
  RESULTS
  A total of 42 conformable nt/aa variations between genotype 3 and 4 HEVs were detected, of which 19 were proposed to be potential disease severity determinants for genotype 4 strains.
  
  
  CONCLUSIONS
  One potential determinant was located in each of the 5'-UTR and 3'-UTR, 3 and 12 within ORF1 and ORF2 respectively, and 2 in the junction region.
authors.affiliation: Institute of Animal Science and Veterinary Medicine, Shanghai Academy of Agricultural Sciences, Shanghai, 201106, China.
authors.forename: Yumin
authors.initials: Y
authors.lastname: Zhu
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Yu
authors.forename: Fenfen
authors.initials: F
authors.lastname: Huang
authors.forename: Ruisong
authors.initials: R
authors.lastname: Yu
authors.forename: Shijuan
authors.initials: S
authors.lastname: Dong
authors.forename: Fusheng
authors.initials: F
authors.lastname: Si
authors.forename: Yuanshu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Zhen
authors.initials: Z
authors.lastname: Li
mesh_terms: D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D000818:Animals; D001483:Base Sequence; D016679:Genome, Viral; D005838:Genotype; D016752:Hepatitis E virus / Q000145:classification / Q000235:genetics* / Q000472:pathogenicity*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D016366:Open Reading Frames; D010802:Phylogeny; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013552:Swine; D014774:Virulence
chemical_list: D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D012367:RNA, Viral