Okamoto H, Nishizawa T, Tawara A, Peng Y, Takahashi M, Kishimoto J, Tanaka T, Miyakawa Y, Mayumi M
Immunology Division and Division of Molecular Virology, Jichi Medical School, Tochigi-Ken 329-0498, Japan.
Virology. 2000 Nov 25;277(2):368-78. doi: 10.1006/viro.2000.0588.
By means of polymerase chain reaction with a primer pair (NG133-NG147) deduced from the untranslated region (UTR) of TT virus (TTV), TTVs with markedly distinct genomic lengths were recovered from sera of humans and nonhuman primates, and their entire nucleotide sequences were determined. A human TTV [TGP96 of 2908 nucleotides (nt)] was obtained that was about 900 nt shorter than heretofore reported TTVs (3787-3853 nt). Likewise, TTVs of chimpanzee occurred in two distinct genomic sizes [Pt-TTV6 (3690 nt) and Pt-TTV8-II (2785 nt)]. Two TTVs of Japanese macaque [Mf-TTV3 (3798 nt) and Mf-TTV9 (3763 nt)] were comparable in genomic length, but only 55% similar in sequence. These five human and nonhuman primate TTVs, along with TTVs of tamarin [So-TTV2 (3371 nt)] and douroucouli [At-TTV3 (3718 nt)], were compared over the entire nucleotide sequence. Although the seven TTVs were only < or = 55% similar, they share a common genomic organization with two open reading frames (ORFs), designated ORF1 (654-735 amino acids) and ORF2 (91-152 amino acids). The N-terminal sequences of ORF1 proteins were rich in arginine, and sequence motifs necessary for transcription and replication were conserved among them all. Like the human prototype TTV (TA278), all seven TTVs from various animals possessed in common two 15-nt sequences (CGAATGGCTGAGTTT and AGGGGCAATTCGGGC) in the UTR that were covered by NG133 and NG147, respectively. These primers would be instrumental in research on TTVs in previously unexamined species for defining their virological characteristics and evolutionary relationships.
通过聚合酶链反应，利用从TT病毒（TTV）非编码区（UTR）推导的引物对（NG133 - NG147），从人和非人灵长类动物血清中回收了基因组长度明显不同的TTV，并测定了它们的完整核苷酸序列。获得了一种人类TTV [2908个核苷酸（nt）的TGP96]，其比迄今报道的TTV（3787 - 3853 nt）短约900 nt。同样，黑猩猩的TTV出现两种不同的基因组大小[Pt - TTV6（3690 nt）和Pt - TTV8 - II（2785 nt）]。日本猕猴的两种TTV [Mf - TTV3（3798 nt）和Mf - TTV9（3763 nt）]基因组长度相当，但序列相似性仅为55%。将这五种人和非人灵长类动物的TTV，与绢毛猴的TTV [So - TTV2（3371 nt）]和夜猴的TTV [At - TTV3（3718 nt）]的整个核苷酸序列进行了比较。尽管这七种TTV的相似性仅≤55%，但它们具有共同的基因组结构，包含两个开放阅读框（ORF），分别命名为ORF1（654 - 735个氨基酸）和ORF2（91 - 152个氨基酸）。ORF1蛋白的N端序列富含精氨酸，转录和复制所需的序列基序在它们之间是保守的。与人类原型TTV（TA278）一样，来自各种动物的所有七种TTV在UTR中共同拥有两个15 nt的序列（CGAATGGCTGAGTTT和AGGGGCAATTCGGGC），分别被NG133和NG147覆盖。这些引物将有助于对以前未检测物种中的TTV进行研究，以确定它们的病毒学特征和进化关系。
