云南西部三地带绦虫生物多态性分子遗传学标记的研究

Study on biologic polymorphism with molecular genetic markers of Taenia cestodes in three western regions of Yunnan

目的利用分子遗传学标记对采自云南西部楚雄、大理和怒江三地带绦虫进行生物多态性研究。方法取云南楚雄株、大理株、怒江株和贵州从江株成虫节片,抽提线粒体DNA,PCR扩增线粒体DNA细胞色素B(mtDNA-Cytb)序列部分区段,并测序;结合GenBank中已知猪带绦虫和亚洲带绦虫mtDNA-Cytb序列,构建系统发育树。结果序列分析显示云南大理和怒江带绦虫mtDNA-Cytb序列部分区段完全一致,同源性为100%;云南楚雄和贵州从江带绦虫mtDNA-Cytb序列部分区段基本一致,同源性为99%。系统发育树显示云南怒江和大理带绦虫与台湾亚洲带绦虫的遗传距离较近,距云南楚雄、贵州从江牛带绦虫较远,与猪带绦虫则更远。结论云南大理和怒江带绦虫属于亚洲带绦虫,云南楚雄带绦虫属于牛带绦虫。mtDNA-Cytb序列分析可以用于带绦虫生物多态性研究。

Objective To study the biologic polymorphism of Taenia cestodes from Chuxiong, Dali, and Nujiang,the three western regions of Yunnan with molecular genetic markers. Methods Mitochondrial DNA was extracted from the proglottis of adult T. cestode strains from Chuxiong, Dali, Nujiang, and Congjiang, respectively, and sequenced. Partial segments of mitochondrial DNA cytochrome B （mtDNA-Cytb） sequences were amplified by polymerase chain reaction （PCR） and sequenced. A phylogenetic tree of species and geographical strains was constructed with other known mtDNA Cytb of Taenia soliurn and Taenia asiatica in GenBank. Results Sequence analysis results suggested that the partial segments of mtDNA Cytb sequences in T. cestode from Dali were genetically consistent with those from Nujiang with a homology of 100% in Yunnan Province. The partial segments of mtDNA-Cytb sequences in T. cestode from Chuxiong in Yunnan Province were genetically consistent with those from Congjiang in Guizhou Province with a homology of 99 %. The phylogenetic tree constructed revealed that the T. cestode from Dali and Nujiang was genetically close to the Taiwan strain but far from those from Chuxiong and Congjiang and even farther from T. solium. Conclusion The T. cestode in Dali and Nujiang falls under T. asiatica and the T. cestode from Chuxiong falls under T. saginata, mtDNA-Cytb sequence analysis could be used to study the biologic polymorphism of T. cestode.