A molecular phylogeny of the Patellogastropoda (Mollusca: Gastropoda)
A molecular phylogeny of the Patellogastropoda (Mollusca: Gastropoda)
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DOI：
10.1007/s002270000332
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发表时间：
2000-09-01
期刊：
影响因子：
2.4
通讯作者：
McArthur, AG
中科院分区：
文献类型：
--
作者：
Harasewych, MG;McArthur, AG
对Patellogastropoda所有现存科、大多数其他主要腹足动物类群（球虫目、Neritopsina、Vetigastropoda、Caenogastropoda、Heterobranchia，但不包括Neomphalina）和软体动物门另外两个纲（头足目、Polyplacophora）的物种的部分18S rDNA序列的系统发育分析证实，Patellogastropoda是一个强大的分支，具有很高的统计支持。这些序列的特点是存在一些插入和缺失，这些插入和缺失是patellogastropod所特有的，并且在patellogastropod中普遍存在。然而，这部分18S基因的信息不足以为腹足动物的单一性提供强有力的支持，也不足以解决腹足动物亚纲分为直腹足动物（=Patellogastropoda +假设的盘曲祖先）和正腹足动物亚纲的问题。这些序列数据总是将Patellogastropoda归为具有球虫形帽贝的弱支持分支，尽管Patellogastropoda和“球虫形门”之间的序列差异大于Patellogastropoda和正腹足类之间的序列差异。部分18S序列支持将Neolepetopsidae家族包含在Acmaeoidea超家族中，并反驳了其先前作为现存Patellogastropoda的姐妹群的假设。18S rDNA基因的这一区域的分化速度差异很大，在patelllogastropod谱系中跨越了一个数量级，因此不能为patelllogastropod高级类群之间的关系提供有意义的解决方案。来自一个或多个比18S rDNA基因（可能是一个或多个线粒体基因）进化更均匀和更快的基因的数据似乎更有可能提供关于Patellogastropoda内部关系的信息。
Phylogenetic analyses of partial 18S rDNA sequences from species representing all living families of the order Patellogastropoda, most other major gastropod groups (Cocculiniformia, Neritopsina, Vetigastropoda, Caenogastropoda, Heterobranchia, but not Neomphalina), and two additional classes of the phylum Mollusca (Cephalopoda, Polyplacophora) confirm that Patellogastropoda comprises a robust clade with high statistical support. The sequences are characterized by the presence of several insertions and deletions that are unique to, and ubiquitous among, patellogastropods. However, this portion of the 18S gene is insufficiently informative to provide robust support for the monophyly of Gastropoda, or to address the division of the Gastropoda into the subclasses Eogastropoda (=Patellogastropoda + hypothetical coiled ancestors) and Orthogastropoda. These sequence data invariably group Patellogastropoda in a weakly supported clade with cocculiniform limpets, despite greater sequence divergences between Patellogastropoda and "Cocculiniformia" than between the Patellogastropoda and Orthogastropoda. Partial 18S sequences support the inclusion of the family Neolepetopsidae within the superfamily Acmaeoidea, and refute its previously hypothesized position as sister group to the remaining living Patellogastropoda. This region of the 18S rDNA gene diverges at widely differing rates, spanning an order of magnitude among patellogastropod lineages, and therefore does not provide meaningful resolution of the relationships among higher taxa of patellogastropods. Data from one or more genes that evolve more uniformly and more rapidly than the 18S rDNA gene (possibly one or more of the mitochondrial genes) seem more likely to be informative about relationships within Patellogastropoda.