Limpets of the genus Nacella (Patellogastropoda) from the Southwestern Atlantic: species identification based on molecular data
Limpets of the genus Nacella (Patellogastropoda) from the Southwestern Atlantic: species identification based on molecular data
复制标题
DOI：
10.1093/mollus/eyp025
复制
发表时间：
2009-08-01
影响因子：
1.2
通讯作者：
Bastida, Ricardo
中科院分区：
文献类型：
--
作者：
De Aranzamendi, M. Carla;Gardenal, Cristina N.;Bastida, Ricardo
水仙属的几个种表现出很高的种内变异性，只有少数的形态特征可以用来鉴定它们，因此它们的分类地位尚不清楚。在这项工作中，分子标记被用来确定在阿根廷巴塔哥尼亚和火地岛海岸观察到的最常见的该属的形式(Nacella Magellanica，Nacella deaurata，Nacella delicatisima和Nacella mytilina)是否是真实的物种，或者是否有一些是单一物种的形态模式。线粒体细胞色素氧化酶I和细胞色素b基因部分序列的最大简约性和贝叶斯系统发育分析表明，包含了所分析的水仙属大多数个体的多角体。使用细胞色素b，在所有被测试的物种中，只有N.mytilina形成了一个支撑良好的分支。4个种间的遗传距离很小，与种内遗传距离相近。相反，ISSRs指纹图谱分析证实了大麦、大麦和大麦的分化。美味新梢小蜂体标本与麦哲伦和北极星天牛的个体混合，表明美味小卷蛾不是一个单独的种，而是另外两个种的一个罕见的形态模式。与线粒体DNA序列相比，ISSR-PCR更有助于揭示近缘物种间的遗传差异。这些结果可以用最近在西南大西洋边缘的物种形成过程来解释。
Several species of the genus Nacella show high phenotypic intraspecific variability and only a few morphological characters can be used to identify them, so that their taxonomic status is unclear. In this work molecular markers were used to determine if the most frequent forms of the genus observed along the coast of Patagonia and Tierra del Fuego in Argentina (Nacella magellanica, Nacella deaurata, Nacella delicatissima and Nacella mytilina) are true species, or if some are morphotypes of a single species. Maximum Parsimony and Bayesian phylogenetic analyses of the partial sequence of the mitochondrial cytochrome oxidase I and cytochrome b genes showed a polytomy comprising most of the individuals of the genus Nacella analysed. Using cytochrome b, among all species tested, only N. mytilina formed a well-supported clade. Interspecific genetic distances among the four Nacella species were very low and similar to the intraspecific ones. On the contrary, intersimple sequence repeats (ISSRs) fingerprint analyses confirmed the differentiation of N. magellanica, N. deaurata and N. mytilina. The specimens of N. delicatissima were intermixed with the individuals of N. magellanica and N. deaurata, suggesting that N. delicatissima is not a separate species but an infrequent morphotype of each of the other two species. ISSR-PCR was more useful in revealing genetic differences among closely related species than mitochondrial DNA sequences. These results could be explained by recent speciation processes in these limpets of the Southwestern Atlantic.