Genetic analysis of Fasciola isolates from cattle in Korea based on second internal transcribed spacer (ITS-2) sequence of nuclear ribosomal DNA
Genetic analysis of Fasciola isolates from cattle in Korea based on second internal transcribed spacer (ITS-2) sequence of nuclear ribosomal DNA
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DOI：
10.1007/s00436-011-2323-6
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发表时间：
2011-09-01
影响因子：
2
通讯作者：
Kang, Seung-Won
中科院分区：
文献类型：
--
作者：
Choe, Se-Eun;Thuy Thi-Dieu Nguyen;Kang, Seung-Won
第二内转录间隔区 (ITS-2) 的核核糖体 DNA 序列已被有效地用于鉴定从不同宿主和不同地理区域收集的肝吸虫种类。对从韩国本地牛采集的 19 个片形吸虫样品的 ITS-2 序列进行了测定和比较。序列比较（包括本研究分离株的 ITS-2 序列）和 Genbank 中肝片形吸虫、巨大片形吸虫和中间片形吸虫的参考序列，揭示了所研究分离株的 7 个相同的可变位点。在19个样本中，12个个体的ITS-2序列与纯肝镰刀菌的ITS-2序列完全相同，5个个体具有与巨镰刀菌型相同的序列，而2个个体具有与肝镰刀菌和巨镰刀菌的序列相同的序列。在属于 F. hepatica 或 F. gigantica 的分离株中没有观察到 ITS-2 序列的长度和核苷酸组成的变化。在218位点，5个含有单碱基取代（C > T）的片形吸虫在F. gigantica型群内形成了一个独特的分支，这与亚洲来源的分离株相似。片吸虫属的系统发育树。基于本研究的完整 ITS-2 序列和不同地点的其他代表性分离株，清楚地表明观察到纯肝片吸虫、巨大片吸虫型和中间片形吸虫。该结果还提供了额外的遗传证据，证明通过使用 ITS-2 序列的遗传方法从韩国本地牛中分离出三种形式的片形吸虫。
Nuclear ribosomal DNA sequence of the second internal transcribed spacer (ITS-2) has been used efficiently to identify the liver fluke species collected from different hosts and various geographic regions. ITS-2 sequences of 19 Fasciola samples collected from Korean native cattle were determined and compared. Sequence comparison including ITS-2 sequences of isolates from this study and reference sequences from Fasciola hepatica and Fasciola gigantica and intermediate Fasciola in Genbank revealed seven identical variable sites of investigated isolates. Among 19 samples, 12 individuals had ITS-2 sequences completely identical to that of pure F. hepatica, five possessed the sequences identical to F. gigantica type, whereas two shared the sequence of both F. hepatica and F. gigantica. No variations in length and nucleotide composition of ITS-2 sequence were observed within isolates that belonged to F. hepatica or F. gigantica. At the position of 218, five Fasciola containing a single-base substitution (C > T) formed a distinct branch inside the F. gigantica-type group which was similar to those of Asian-origin isolates. The phylogenetic tree of the Fasciola spp. based on complete ITS-2 sequences from this study and other representative isolates in different locations clearly showed that pure F. hepatica, F. gigantica type and intermediate Fasciola were observed. The result also provided additional genetic evidence for the existence of three forms of Fasciola isolated from native cattle in Korea by genetic approach using ITS-2 sequence.