Abstract: Objective　To investigate the genetic variation of Eurytrema pancreaticum isolated from goats in Huaihua City, Hunan Province. Methods　The partial sequence of mitochondrial cytochrome I (pcox1) and ribosomal 18S rRNA genes were amplified using a PCR assay in E. pancreaticum isolates from goats in Huaihua City, Hunan Province, and the PCR amplification products were sequenced. Then, the gene sequences were subjected to genetic variation and phylogenetic analyses. Results　The sequences of the pcox1 and 18S rRNA genes were 430 bp and 1 857 bp in length in 18 E. pancreaticum isolates from goats in Huaihua City, Hunan Province, and there were 14 and 35 variation sites in pcox1 and 18S rRNA gene sequences, with intra?species genetic variations of 0 to 1.4% and 0 to 0.8%, respectively. The sequences of pcox1 and 18S rRNA genes had 99.0% to 99.8% and 99.5% to 99.8% homologies with those from E. pancreaticum Chinese strain recorded in the GenBank database. Consistent phylogenetic analysis results were found based on pcox1 and 18S rRNA genes. The 18 E. pancreaticum isolates from goats in Huaihua City were clustered into a clade with the known E. pancreaticum isolates registered in GenBank, and the clade with these 18 E. pancreaticum isolates was close to the clades with Eurytrema species and far from the clades with other trematodes. Conclusions The E. pancreaticum isolates from goats have a low genetic variation in Huaihua City, Hunan Province. Mitochondrial pcox1 and ribosomal 18S rRNA genes may serve as molecular markers for the studies on the genetic variation in goat?derived E. pancreaticum.

Key words: Eurytrema pancreaticum, Goat, pcox1 gene, 18S rRNA gene, Genetic variation, Huaihua City

摘要： 目的　了解湖南省怀化地区山羊体内分离的胰阔盘吸虫遗传变异情况。方法　应用PCR技术对分离自湖南怀化地区山羊体内的18株胰阔盘吸虫分离株线粒体细胞色素c氧化酶亚基I基因部分序列（pcox1）和核糖体18S rRNA基因进行扩增，对扩增产物进行测序并进行遗传变异和系统发育分析。结果　分离自湖南怀化地区山羊体内的18株胰阔盘吸虫分离株pcox1和18S rRNA基因序列长度分别为430 bp和1 857 bp，分别存在14个和35个变异位点，种内遗传差异分别为0 ~ 1.4%和0 ~ 0.8%；与GenBank数据库中收录的胰阔盘吸虫中国株基因序列同源性最高，分别为99.0% ~ 99.8%和99.5% ~ 99.8%。基于两种基因构建的系统发育树分析结果一致，本研究获得的18株胰阔盘吸虫分离株与GenBank数据库中已知胰阔盘吸虫分离株聚为同一分支，与支睾阔盘吸虫等阔盘属吸虫相隔较近，与其他吸虫所属分支相隔较远。结论　湖南省怀化地区山羊源胰阔盘吸虫分离株遗传变异度较低，线粒体pcox1基因和核糖体18S rRNA基因均适合作为羊源胰阔盘吸虫遗传变异研究的分子标记。

关键词: 胰阔盘吸虫, 山羊, pcox1基因, 18S rRNA 基因, 遗传变异, 怀化地区