In the flatworm genus Schistosoma, species of which include parasites of biomedical and veterinary importance, mitochondrial gene order is radically different in some species. A PCR-based survey of 19 schistosomatid spp. established which of 14 Schistosoma spp. have the ancestral (plesiomorphic) or derived gene order condition. A phylogeny for Schistosoma was estimated and used to infer the origin of the gene order change which is present in all members of a clade containing Schistosoma incognitum and members of the traditionally recognised Schistosoma indicum, Schistosoma mansoni and Schistosomahaematobium spp. groups. Schistosoma turkestanicum, with the plesiomorphic gene order state, is sister to this clade. Common interval analysis suggests change in gene order, from ancestral to derived, consisted of two sequential transposition events: (a) nad1_nad3 to nad3_nad1 and (b) [atp6,nad2]_[nad3,-nad1,cox1,rrnL,rrnS,cox2,nad6] to [nad3,nad1,cox1,rrnL,rrnS,cox2,nad6]_[atp6,nad2], where gene order offragments within square brackets remain unchanged. Gene order change is rare in parasitic flatworms and is a robust synapomorphy for schistosome spp. that exhibit it. The schistosomatid phylogeny casts some doubt on the origin of Schistosoma (Asian or African), highlights the propensity for species to hosts witch amongst mammalian (definitive) hosts, and indicates the likely importance of snail (intermediate)hosts in determining and defining patterns of schistosome radiation and continental invasion. Mitogenomic sampling of Schistosoma dattai and Schistosoma harinasutai to determine gene order, and within key species, especially S. turkestanicum and S. incognitum, to determine ancestral ranges, may help discover the geographic origins of gene order change in the genus. Samples of S. incognitum from India and Thailand suggest this taxon may include cryptic species.

中文翻译：

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血吸虫的线粒体基因顺序改变（蠕虫：双基因：血吸虫科）。

在扁虫属的血吸虫属中，其物种包括具有生物医学和兽医学重要性的寄生虫，线粒体基因顺序在某些物种中是根本不同的。基于PCR的19种血吸虫病菌调查。确定了14个血吸虫属中的哪个。具有祖先的（多形的）或衍生的基因有序条件。估计了血吸虫的系统发育，并用于推断基因顺序改变的起源，该顺序存在于包含隐血吸虫的进化枝的所有成员以及传统认可的印度血吸虫，曼氏血吸虫和血吸虫血球菌属的物种中。组。具有多形性基因有序状态的土耳其血吸虫是该进化枝的姐妹。常见间隔分析表明，从祖先到衍生的基因顺序变化包括两个连续的转座事件：（a）nad1_nad3至nad3_nad1和（b）[atp6，nad2] _ [nad3，-nad1，cox1，rrnL，rrnS，cox2，nad6]至[nad3，nad1，cox1，rrnL，rrnS，cox2，nad6] _ [ atp6，nad2]，其中方括号内的基因顺序杂乱性保持不变。基因顺序的改变在寄生扁虫中很少见，并且是血吸虫的强大的突触同形。展示它。血吸虫的系统发育对血吸虫（亚洲或非洲）的起源提出了一些怀疑，突出了该物种在哺乳动物（定居）寄主中寄居巫婆的倾向，并指出了蜗牛（中生）寄主在确定和定义血吸虫病模式方面的重要性。辐射和大陆入侵。达氏血吸虫和harinasutai血吸虫的线粒体采样，以确定基因顺序，并在关键物种内，尤其是土库曼链球菌和隐身链球菌，确定祖先范围，可能有助于发现属中基因顺序变化的地理起源。来自印度和泰国的隐身链球菌样品表明该分类单元可能包括隐性物种。