Genomic characterization of TT viruses (TTVs) in pigs, cats and dogs and their relatedness with species-specific TTVs in primates and tupaias
Genomic characterization of TT viruses (TTVs) in pigs, cats and dogs and their relatedness with species-specific TTVs in primates and tupaias
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DOI：
10.1099/0022-1317-83-6-1291
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发表时间：
2002-06-01
影响因子：
3.8
通讯作者：
Yoshikawa, A
中科院分区：
文献类型：
--
作者：
Okamoto, H;Takahashi, M;Yoshikawa, A
使用来自人TT病毒（TTV）基因组非编码区的引物进行PCR，鉴定了猪（Sus arcticus）、犬（Canis familiaris）和猫（Felis卡图斯）血清样品中的TTV序列，并测定了每种代表性分离株的完整基因组序列。三个TTV分离物（来自猪的Sd-TTV 31、来自狗的Cf-TTV 10和来自猫的Fc-TTV 4）分别包含2878、2797和2064个核苷酸，每个都具有三个开放阅读框（ORF），编码436-635（ORF 1）、73-105（ORF 2）和224-243（ORF 3）aa，但缺少ORF 4，类似于树鼩 TTV。ORF 3被认为是由TTV mRNA的剪接产生的，类似于人类原型TTV。尽管Sd-TTV 31、Cf-TTV 10和Fc-TTV 4的核苷酸序列彼此之间以及与先前报道的3.4-3.9 kb的TTV和分离自人和非人灵长类动物的2.8-3.0 kb的TTV样微型病毒（TLMV）以及2.2 kb的树鼩 TTV的核苷酸序列之间的差异超过50%，它们在基因组结构和假定的转录谱方面类似于已知的TTV和TLMV，而不是1.7- 2.3kb的动物圆环病毒。系统进化分析表明，Sd-TTV 31、Cf-TTV 10和Fc-TTV 4与低等灵长类和树鼩的TTV的亲缘关系较近，而与高等灵长类的TTV和TLMV的亲缘关系较远。这些结果表明，家猪，猫和狗自然感染具有小基因组大小的物种特异性TTV，并表明在动物中具有极其不同的基因组序列和长度的TTV广泛分布。
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.