Molecular phylogeny of Pholadoidea Lamarck, 1809 supports a single origin for xylotrophy (wood feeding) and xylotrophic bacterial endosymbiosis in Bivalvia
Molecular phylogeny of Pholadoidea Lamarck, 1809 supports a single origin for xylotrophy (wood feeding) and xylotrophic bacterial endosymbiosis in Bivalvia
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DOI：
10.1016/j.ympev.2011.05.019
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发表时间：
2011-11-01
影响因子：
4.1
通讯作者：
Yang, Joyce
中科院分区：
文献类型：
--
作者：
Distel, Daniel L.;Amin, Mehwish;Yang, Joyce
以木材为食物的能力在动物中是不寻常的。在陆地环境中，白蚁和其他木材营养型昆虫是主要的木材消费者，而在海洋环境中，钻木双壳类履行这一角色。然而，在双壳类动物中木材喂养的进化起源仍然在很大程度上未被探索。在这里，我们提供的数据表明，木营养已经出现了一次在双壳类在一个单一的木材喂养双壳类血统，随后多样化成不同的浅水和深水分支，这两个已经广泛成功地殖民世界的海洋。这些数据还表明，这种显著的生活习性的出现与细菌内共生体的获得大致一致。在这里，我们产生了一个强大的双壳类和相关物种的小，大亚基核rRNA基因序列的基础上的同源性。然后，我们跟踪现代类群的形态特征和特征状态与xylotrophy和xylotrepesis（木材钻孔）之间的分布，并使用简约为基础的方法来推断他们的祖先状态。基于这些祖先的状态重建，我们提出了一套合理的假说，描述了双壳类共生木营养的进化。在此背景下，我们重新解释了一个最显着的进展，在双壳类的进化，改造的“典型”myoid身体计划，创造一个独特的血统蠕虫状，管形成，木材喂养蛤。这里提出的充分支持的单系发生与大多数木质营养型双壳类的分类学处理不一致，表明双壳类Pholadidae家族和Teredinae家族的Teredininae和Bankiinae亚科是非单系的，并且用于其分类诊断的主要性状在单系发生上是误导的。(C)2011 Elsevier Inc. All rights reserved.
The ability to consume wood as food (xylotrophy) is unusual among animals. In terrestrial environments, termites and other xylotrophic insects are the principle wood consumers while in marine environments wood-boring bivalves fulfill this role. However, the evolutionary origin of wood feeding in bivalves has remained largely unexplored. Here we provide data indicating that xylotrophy has arisen just once in Bivalvia in a single wood-feeding bivalve lineage that subsequently diversified into distinct shallow-and deep-water branches, both of which have been broadly successful in colonizing the world's oceans. These data also suggest that the appearance of this remarkable life habit was approximately coincident with the acquisition of bacterial endosymbionts. Here we generate a robust phylogeny for xylotrophic bivalves and related species based on sequences of small and large subunit nuclear rRNA genes. We then trace the distribution among the modern taxa of morphological characters and character states associated with xylotrophy and xylotrepesis (wood-boring) and use a parsimony-based method to infer their ancestral states. Based on these ancestral state reconstructions we propose a set of plausible hypotheses describing the evolution of symbiotic xylotrophy in Bivalvia. Within this context, we reinterpret one of the most remarkable progressions in bivalve evolution, the transformation of the "typical" myoid body plan to create a unique lineage of worm-like, tube-forming, wood-feeding clams. The well-supported phylogeny presented here is inconsistent with most taxonomic treatments for xylotrophic bivalves, indicating that the bivalve family Pholadidae and the subfamilies Teredininae and Bankiinae of the family Teredinidae are non-monophyletic, and that the principle traits used for their taxonomic diagnosis are phylogenetically misleading. (C) 2011 Elsevier Inc. All rights reserved.