Lavikainen A, Lehtinen M J, Meri T, Hirvelä-Koski V, Meri S
Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, P.O. Box 21, FIN-00014, University of Helsinki, Finland.
Parasitology. 2003 Sep;127(Pt 3):207-15. doi: 10.1017/s0031182003003780.
The northern biotype of Echinococcus granulosus occurs in North America and northern Eurasia in life-cycles involving cervids. Previously, cervid isolates of E. granulosus from North America have been characterized using molecular genetic techniques as the G8 genotype. In this study, 5 isolates of E. granulosus were collected from 4 reindeer and 1 moose in north-eastern Finland. DNA sequences within regions of mitochondrial cytochrome c oxidase I (COI) and NADH dehydrogenase I (NI)I) genes and the internal transcribed spacer 1 (ITS-1) fragment of the ribosomal DNA were analysed. The mitochondrial nucleotide sequences were identical in all isolates, but high sequence variation was found in the ITS-1 region. Mitochondrial and nuclear sequences of the Finnish cervid E. granulosus and the camel strain (G6) of E. granulosus resembled closely each other. According to phylogenetic analyses, the Finnish isolates have close relationships also with the pig (G7) and cattle (G5) strains. Although some similarities were found with the previously published North American cervid strain (G8), particularly in the NDI sequence and some of the ITS-1 clones, the Finnish E. granulosus form represents a distinct, previously undescribed genotype of E. granulosus. The novel genotype is hereby named as the Fennoscandian cervid strain (G10).
细粒棘球绦虫的北方生物型存在于北美洲和欧亚大陆北部，其生命周期涉及鹿类。此前，利用分子遗传学技术已将来自北美洲的细粒棘球绦虫鹿类分离株鉴定为G8基因型。在本研究中，从芬兰东北部的4头驯鹿和1头驼鹿身上采集了5株细粒棘球绦虫分离株。分析了线粒体细胞色素c氧化酶I（COI）和NADH脱氢酶I（NDI）基因区域以及核糖体DNA的内部转录间隔区1（ITS-1）片段的DNA序列。所有分离株的线粒体核苷酸序列均相同，但在ITS-1区域发现了高度的序列变异。芬兰鹿类细粒棘球绦虫的线粒体和核序列与细粒棘球绦虫骆驼株（G6）非常相似。根据系统发育分析，芬兰分离株与猪（G7）和牛（G5）株也有密切关系。尽管与先前发表的北美鹿类株（G8）有一些相似之处，特别是在NDI序列和一些ITS-1克隆中，但芬兰细粒棘球绦虫类型代表了一种独特的、先前未描述的细粒棘球绦虫基因型。在此将这种新基因型命名为芬诺斯堪的亚鹿类株（G10）。
