云贵两省三地牛带绦虫核糖体rDNA-ITS1序列分析

Molecular Identification of Taenia saginata from Three Regions of Yunnan and Guizhou Provinces——Sequence analysis of the first internal transcription spacer(ITS1) of ribosomal DNA

目的：采用PCR克隆测序方法，对采自贵州省都匀、从江及云南省大理三地牛带绦虫，与台湾桃园牛带绦虫亚洲亚种标本进行比较，为贵州都匀、从江及云南大理牛带绦虫标本鉴别提供分子生物学证据，并进一步探讨牛带绦虫亚洲亚种分类学地位。方法：取贵州都匀株、贵州从江株、云南大理株和台湾桃园株成虫节片，抽提DNA，PCR扩增rDNA-ITS1区段，克隆测序；结合GenBank中已知猪带绦虫rDNA-ITS1序列，构建系统发育树。结果：贵州都匀、云南大理牛带绦虫标本、台湾牛带绦虫亚洲亚种标本的ITS1序列基本一致，同源性达98％～99％；贵州从江牛带绦虫标本ITS1序列与前三者有30个碱基差异，与台湾桃园、贵州都匀和云南大理同源性均为97％。系统发育树显示：贵州都匀和云南大理牛带绦虫标本与台湾牛带绦虫亚洲亚种标本的遗传距离最接近，距贵州从江牛带绦虫标本较远，与猪带绦虫则更远。结论：（1）贵州都匀和云南大理牛带绦虫标本属于牛带绦虫亚洲亚种，贵州从江牛带绦虫标本属于传统牛带绦虫。（2）rDNA-ITS1序列分析可以用于牛带绦虫亚洲亚种与传统带绦虫分类学研究。

Objective： To study the Taenia saginata samples from Guizhou Duyun, Congjiang in Guizhou Province and Dali in Yunnan Province with DNA sequencing method, in order to obtain molecular evidence for the identification of strains from Guizhou, Yunnan and Xinjiang. Methods： Genomic DNA was extracted from the segments of adult tapeworms from Taoyuan （Taiwan Province）, Dali, Duyun and Congjiang respectively; rDNA-ITS1 gene sequences （ITS1S） were amplified by PCR and, then, cloned and sequenced. Phylogenetic tree of different geographical strains was constructed with other known ITS1S of T. solium in GenBank. Results. Sequence analysis results suggested that the ITS1S of T. saginata asiatica from Taoyuan, Dali and Duyun were fundamentally identical, and the homology of them reached 98% - 99%. There was ,a 30-base difference between the ITS1S of the strain from Congjiang, and those from the three regions mentioned above. The homology of the ITS1S of the strain from Congjiang with them was 97%. The phylogenetic tree constructed revealed that Duyun strain and Dali strain were close to Taiwan strain genetically, but far from Congjiang strain and even farther from T. solium. Conclusions： （ 1 ） Duyun strain and Dali strain belong to T. saginata asiatica, and Congjiang strain belongs to typical T. saginata; （2） rDNA -ITS1 sequence analysis could be used in taxological study of T. saginata asiatica and typical T. saginata.