【摘要】 为阐明来自中国、尼日尔、法国和美国的片形吸虫分离株在线粒体烟酰胺腺嘌呤二核苷酸(NADH)脱氢酶亚单位1基因(nad1)部分序列(pnad1)的遗传变异情况,并以pnad1序列进行种系发育研究,利用PCR扩增了中国、尼日尔、法国和美国片形吸虫分离株的pnad1序列并与GenBankTM中片形吸虫相应序列进行了比较,进行了种系发育分析。结果显示,所有片形吸虫样品的pnad1序列长度均为446 bp,中国、尼日尔、法国和美国肝片吸虫分离株与GenBankTM公布的肝片吸虫相应序列的种内变异为0.2%～0.7%,0.2%～0.9%,0.9%～2.0%,0.2%～0.9%;中国及尼日尔大片吸虫分离株与已报道的大片吸虫相应序列的种内变异为1.8%～2.7%,1.8%～3.4%;中国中间型虫株与中国及尼日尔大片吸虫分离株以及网上报道的大片吸虫的序列差异为5.6%～6.3%,5.6%～7.8%,5.7%～8.1%。中间型片形吸虫在遗传学上介于大片吸虫与肝片吸虫之间,但与大片吸虫的遗传关系更近。表明,片形吸虫pnad1序列可作为种间鉴定及种内遗传变异研究的标记;在中国的确存在中间型片形吸虫。更多还原

【Abstract】 In order to examine sequence variation in the mitochondrial(mt) NADH dehydrogenase subunit 1(nad1) gene among Fasciola spp.from China,Niger,France and USA and to reconstruct their phylogenetic relationship using nad1 sequences,the partial nad1(pnad1) was amplified from each Fasciola samples,sequenced and compared with relevant sequences available in GenBankTM.Phylogenetic relationship was reconstructed using the neighbour-joining,maximum parasimony and maximum likelihood methods.The lengths of all pnad1 sequences was 446 bp.Sequence comparison revealed that the variation in pnad1 sequences among F.hepatica isolates ranged from 0.2% to 2.0%,while the variation among F.gigantica isolates ranged from 1.8% to 3.4%.The pnad1 sequences of the intermediate Fasciola were similar to that of F.gigantica.Phylogenetic analysis revealed that the intermediate Fasciola was genetically closer to F.gigantica than to F.hepatica.Sequence differences in pnad1 sequences were significantly greater than nucleotide variation within species,indicating that nad1 sequence can be used as genetic marker for the speci-fic differentiation among Fasciola spp.and studying genetic variation within each Fasciola spp..This study also provided novel mtDNA evidence for the existence of the intermediate Fasciola in China.更多还原