Studies on speciation of Asian schistosomes

亚洲血吸虫形态研究

基本信息

批准号：
07041120
负责人：
AGATSUMA Takeshi
金额：
$ 10.05万
依托单位：
Obihiro University of Agriculture and Veterinary Medicine
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07041120/
关键词：
S.japonicum S.mekongi S.malaynsis S.sinensium PCR COI ITS2 speciation phylogenetic tree 染色体C-バンドキアズマ染色体核型

项目摘要

Asian schistosomes appear to fall into several phylogenetic groups. One of these includes Schistosoma japonicum, S.mekongi, and S.malaynsis which appear closely related to one another. The placement of S.sinensium is still debaded. It seems to possess some characteristics intermediate between S.japonicum and S.mansoni (Greer et al., 1989). S.spindale seems closest to Afrian species (Barker & Blair, 1996), and perhaps most similar to S.bovis. Very different snail hosts are used by the different parasites, Oncomelania (S.japonicum), Neotricula (S.mekongi), Robertsiella (S.malaynsis), Tricula (S.sinensium), Indoplanorbis (S.spindale), and Lymnea (S.incognitum). Schistosoma host specificities are extremely high. The present study was done to examine evolutionay relationships among some of Asian and African species of Schistosoma using mitochondrial (COI) and nuclear (ITS 2) DNA.It was found that S.mekongi and S.malaynsis were sisters to S.japonicum, based on DNA sequences. Our data also indicate that the S.sinensium ITS2 region contains two deletions, each shared with S.japonicum and S.mansoni. S.sinensium was placed at the base of the S.japonicum group. This fact strongly suggests that S.sinencium could be an ancestal species of S.japonicum. Recently, we were able to obtain S.incognitum from Jakarta, Indonesia, and to amplify the COI and ITS2 region. Basedn the computor analysis using Neighbor joining and UPGMA method, it was found that this blood fluke differs in many base pair sites from the other Asian blood flukes, and belongs to African blood flukes like S.mansoni or S.haematobium. This suggests that this parasite is of African origin and has migrated to Asia very recently (within last 100 thousands years).

亚洲血块似乎属于多个系统发育群体。其中之一包括Japonicum，S.Mekongi和S.Malaynsis，它们彼此之间似乎密切相关。 S.sinensium的放置仍被剥夺。它似乎具有s. japonicum和s.mansoni之间的一些特征（Greer等，1989）。 S.Spindale似乎最接近Afrian物种（Barker＆Blair，1996），也许与S.Bovis最相似。不同的蜗牛宿主由不同的寄生虫（S.japonicum），新疾病（S.mekongi），Robertsiella（s.malaynsis），Tricula（S.sinensium），Indoplanorbis（S.Spindale）和Lymnea（S.incognitum）使用。血吸虫宿主特异性极高。本研究是为了检查亚洲和非洲某些血吸虫物种之间使用线粒体（COI）和核（其2）DNA之间的进化关系。我们的数据还表明，S.sinensium ITS2区域包含两个缺失，每个缺失都与S.Japonicum和S.mansoni共享。 S.sinensium被放置在S.japonicum组的底部。这一事实强烈表明，s. s.sinencium可能是japonicum的祖先物种。最近，我们能够从印度尼西亚的雅加达获得s.incognitum，并扩大COI及其2区域。基于使用邻居加入和UPGMA方法的计算机分析，发现这种血液在许多基对部位与其他亚洲血液浮动的不同，并且属于S.mansoni或S.haematobium等非洲血液氟。这表明该寄生虫是非洲起源的，并且最近迁移到亚洲（在过去的100千年之内）。