title: Genomic characterization of TT viruses (TTVs) in pigs, cats and dogs and their relatedness with species-specific TTVs in primates and tupaias.
abstract: Using PCR with primers derived from a non-coding region of the human TT virus (TTV) genome, the TTV sequence in serum samples obtained from pigs (Sus domesticus), dogs (Canis familiaris) and cats (Felis catus) was identified and the entire genomic sequence was determined for each representative isolate. Three TTV isolates (Sd-TTV31 from a pig, Cf-TTV10 from a dog and Fc-TTV4 from a cat) comprising 2878, 2797 and 2064 nucleotides, respectively, each had three open reading frames (ORFs) encoding 436-635 (ORF1), 73-105 (ORF2) and 224-243 (ORF3) aa but lacked ORF4, similar to tupaia TTV. ORF3 was presumed to arise from a splicing of TTV mRNA, similar to human prototype TTV. Although the nucleotide sequence of Sd-TTV31, Cf-TTV10 and Fc-TTV4 differed by more than 50% from each other and from previously reported TTVs of 3.4-3.9 kb and TTV-like mini viruses (TLMVs) of 2.8-3.0 kb isolated from humans and non-human primates as well as tupaia TTVs of 2.2 kb, they resembled known TTVs and TLMVs with regard to genomic organization and presumed transcriptional profile rather than animal circoviruses of 1.7-2.3 kb. Phylogenetic analysis revealed that Sd-TTV31, Cf-TTV10 and Fc-TTV4 were closer to TTVs from lower-order primates and tupaias than to TTVs from higher-order primates and TLMVs. These results indicate that domestic pigs, cats and dogs are naturally infected with species-specific TTVs with small genomic size and suggest a wide distribution of TTVs with extremely divergent genomic sequence and length in animals.
authors.affiliation: Immunology Division and Division of Molecular Virology, Jichi Medical School, Tochigi-Ken 329-0498, Japan1.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Okamoto
authors.affiliation: Immunology Division and Division of Molecular Virology, Jichi Medical School, Tochigi-Ken 329-0498, Japan1.
authors.forename: Masaharu
authors.initials: M
authors.lastname: Takahashi
authors.affiliation: Immunology Division and Division of Molecular Virology, Jichi Medical School, Tochigi-Ken 329-0498, Japan1.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nishizawa
authors.affiliation: First Department of Internal Medicine, Yamanashi Medical University, Yamanashi-Ken 409-3898, Japan2.
authors.forename: Akio
authors.initials: A
authors.lastname: Tawara
authors.affiliation: Central Animal Hygiene Service Center of Tochigi Prefecture, Tochigi-Ken 321-0905, Japan3.
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Fukai
authors.affiliation: Central Animal Hygiene Service Center of Tochigi Prefecture, Tochigi-Ken 321-0905, Japan3.
authors.forename: Umetaro
authors.initials: U
authors.lastname: Muramatsu
authors.affiliation: Department of Clinical Veterinary Medicine, Faculty of Agriculture, Iwate University, Iwate-Ken 020-8550, Japan4.
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Naito
authors.affiliation: Japanese Red Cross Saitama Blood Center, Saitama-Ken 338-0001, Japan5.
authors.forename: Akira
authors.initials: A
authors.lastname: Yoshikawa
mesh_terms: D000818:Animals; D001483:Base Sequence; D002415:Cats / Q000821:virology*; D004285:Dogs / Q000821:virology*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010802:Phylogeny; D011323:Primates / Q000821:virology*; D016415:Sequence Alignment; D013045:Species Specificity; D013552:Swine / Q000821:virology*; D022783:Torque teno virus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D014417:Tupaia / Q000821:virology*