We investigated the phylogeny of the viviparid genus Margarya,endemic to Yunnan,China,using two mitochondrial gene fragments(COI and 16S rRNA).The molecular phylogeny based on the combined dataset indicates that Marga...We investigated the phylogeny of the viviparid genus Margarya,endemic to Yunnan,China,using two mitochondrial gene fragments(COI and 16S rRNA).The molecular phylogeny based on the combined dataset indicates that Margarya is polyphyletic,as two of the three well-supported clades containing species of Margarya also comprise species from other viviparid genera.In one clade,sequences of four species of Margarya even cluster indiscriminately with those of two species of Cipangopaludina,indicating that the current state of Asian viviparid taxonomy needs to be revised.Additionally,these data suggest that shell evolution in viviparids is complex,as even the large and strongly sculptured shells of Margarya,which are outstanding among Asian viviparids,can apparently be easily converted to simple smooth shells.The molecular data also indicate that the species status of the six extant species of Margarya should be re-assessed.展开更多
目的建立田螺科已有种类的系统发育关系,探讨螺蛳(Margarya melanioides)的分类地位.方法测定采自云南高原湖泊中的螺蛳、方形环棱螺和中华圆田螺的线粒体COI、16S r RNA基因序列,并结合Gen Bank中田螺科已有物种序列,计算螺蛳和其他主...目的建立田螺科已有种类的系统发育关系,探讨螺蛳(Margarya melanioides)的分类地位.方法测定采自云南高原湖泊中的螺蛳、方形环棱螺和中华圆田螺的线粒体COI、16S r RNA基因序列,并结合Gen Bank中田螺科已有物种序列,计算螺蛳和其他主要类群的遗传距离,用最大简约法(MP)、最大似然法(ML)和贝叶斯法(BI)构建包含螺蛳的田螺科部分物种系统发育树.结果 COI基因第三位密码子转换已达到饱和.在COI基因片段数据集、COI第1,2位密码子数据子集、16S基因片段数据集中,螺蛳与圆田螺属的遗传距离最小.在MP法、ML法、BI法构建的系统发育树中,螺蛳和中华圆田螺聚为一支,我国的环棱螺属种类和非洲该属未聚在一起.结论螺蛳与中华圆田螺的亲缘关系较近,线粒体COI联合16S基因片段可以弥补形态学在研究田螺科物种系统发育关系时的不足.展开更多
基金supported by a GEF Median Size Project (TF051795)Development Marketplace Global Competition Project (DM01333)+1 种基金Yunnan Provincial Science,Technology Department Social Development Science and Technology Plans (2008CA001)National Natural Science Foundation of China (30730017)
文摘We investigated the phylogeny of the viviparid genus Margarya,endemic to Yunnan,China,using two mitochondrial gene fragments(COI and 16S rRNA).The molecular phylogeny based on the combined dataset indicates that Margarya is polyphyletic,as two of the three well-supported clades containing species of Margarya also comprise species from other viviparid genera.In one clade,sequences of four species of Margarya even cluster indiscriminately with those of two species of Cipangopaludina,indicating that the current state of Asian viviparid taxonomy needs to be revised.Additionally,these data suggest that shell evolution in viviparids is complex,as even the large and strongly sculptured shells of Margarya,which are outstanding among Asian viviparids,can apparently be easily converted to simple smooth shells.The molecular data also indicate that the species status of the six extant species of Margarya should be re-assessed.
