State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Animal Virology of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agriculture Sciences, Lanzhou, Gansu 730046, PR China.
Virol J. 2011 Jun 26;8:320. doi: 10.1186/1743-422X-8-320.
Porcine parvovirus (PPV) usually causes reproductive failure in sows. The objective of the present study was to analyze the phylogenetic distribution and perform molecular characterization of PPVs isolated in China, as well as to identify two field strains, LZ and JY. The data used in this study contained the available sequences for NS1 and VP2 from GenBank, as well as the two aforementioned Chinese strains.
Phylogenetic analysis shows that the PPV sequences are divided into four groups. The early Chinese PPV isolates are Group I viruses, and nearly all of the later Chinese PPV isolates are Group II viruses. LZ belongs to group II, whereas the JY strain is a Group III virus. This is the first report on the isolation of a Group III virus in China. The detection of selective pressures on the PPV genome shows that the NS1 and VP2 genes are under purifying selection and positive selection, respectively. Moreover, the amino acids in the VP2 capsid are highly variable because of the positive selection.
Our study provides new molecular data on PPV strains in China, and emphasizes the importance of etiological studies of PPV in pigs.
猪细小病毒（PPV）通常会导致母猪繁殖失败。本研究的目的是分析中国分离的 PPV 的系统发育分布和进行分子特征分析，并鉴定出两个田间分离株，LZ 和 JY。本研究使用的数据包含来自 GenBank 的 NS1 和 VP2 的可用序列，以及上述两个中国分离株。
系统发育分析表明，PPV 序列分为四个组。早期的中国 PPV 分离株属于组 I 病毒，而几乎所有后来的中国 PPV 分离株都属于组 II 病毒。LZ 属于组 II，而 JY 株是组 III 病毒。这是中国首次报道分离出组 III 病毒。对 PPV 基因组的选择压力检测表明，NS1 和 VP2 基因分别受到纯化选择和阳性选择。此外，VP2 衣壳上的氨基酸由于阳性选择而高度可变。
本研究为中国的 PPV 株提供了新的分子数据，并强调了对猪源 PPV 的病因学研究的重要性。
