Zhao G H, Li J, Chen F, Zou F C, Yang J F, Sugiyama H, Xu M J, Lin Q, Lin R Q, Zhu X Q
College of Veterinary Medicine, Northwest A & F University, Yangling, Shaanxi Province 712100, PR China.
Parasitol Int. 2011 Jun;60(2):170-4. doi: 10.1016/j.parint.2011.01.008. Epub 2011 Feb 2.
The accurate characterization of Schistosoma japonicum has important implications for analyzing genetic variation and would provide basic data for disease control. Previous studies using proteins, coding sequences, and especially antigen-coding genes showed lower genetic variation among S. japonicum isolates from mainland China. Therefore, the present study focused on variations in intron sequences of housekeeping and antigen-coding genes, which may be more informative for genetic analysis. We compared sequence variation between introns of two housekeeping genes and two antigen-coding genes. All 4 genes were polymorphic among all the S. japonicum isolates in mainland China, with 103, 158, 47, and 19 polymorphic (segregating) sites per kilobase in intron sequences of Actin, FBPA, 22.6kDa antigen and GST-26, respectively. Introns of housekeeping genes were slightly more polymorphic than coding and non-coding regions of antigen-coding genes examined in the present study within or among lake/marshland and mountainous types. Phylogenetic analysis based on sequences of single gene or combined sequences of multiple genes showed no specific clustering comprising parasites from single geographical or endemic regions. These results demonstrated that introns of housekeeping and antigen-coding genes were polymorphic, but the intron sequences examined in the present study were not suitable markers for examining genetic relationship among different isolates from endemic regions in mainland China.
日本血吸虫的准确特征描述对分析遗传变异具有重要意义，并将为疾病控制提供基础数据。以往使用蛋白质、编码序列尤其是抗原编码基因的研究表明，中国大陆日本血吸虫分离株之间的遗传变异较低。因此，本研究聚焦于管家基因和抗原编码基因内含子序列的变异，这可能对遗传分析更具信息量。我们比较了两个管家基因和两个抗原编码基因内含子之间的序列变异。在中国大陆所有日本血吸虫分离株中，所有这4个基因均具有多态性，肌动蛋白（Actin）、果糖二磷酸醛缩酶（FBPA）、22.6 kDa抗原和谷胱甘肽S-转移酶26（GST-26）的内含子序列中每千碱基分别有103、158、47和19个多态性（分离）位点。在湖泊/沼泽型和山区型内部或之间，本研究中检测的管家基因内含子的多态性略高于抗原编码基因的编码区和非编码区。基于单基因序列或多个基因组合序列的系统发育分析表明，不存在来自单一地理或流行区域的寄生虫的特定聚类。这些结果表明，管家基因和抗原编码基因的内含子具有多态性，但本研究中检测的内含子序列并非用于检测中国大陆流行区不同分离株之间遗传关系的合适标记。
