An integrative systematic framework helps to reconstruct skeletal evolution of glass sponges (Porifera, Hexactinellida).
An integrative systematic framework helps to reconstruct skeletal evolution of glass sponges (Porifera, Hexactinellida).
复制标题
DOI：
10.1186/s12983-017-0191-3
复制
发表时间：
2017
影响因子：
2.8
通讯作者：
Reiswig HM
中科院分区：
文献类型：
--
作者：
Dohrmann M;Kelley C;Kelly M;Pisera A;Hooper JNA;Reiswig HM
玻璃海绵(六角类)是深海生态系统的重要组成部分，在地质和材料科学方面具有重要意义。用分子数据重建它们的系统发育才刚刚开始，与其他海绵类群的典型系统学相比，基于形态的系统学显示出更好的一致性，这可能是因为有更多的信息丰富的形态特征。然而，不一致的情况仍然存在，这对关于它们主要骨骼构造类型(身体平面)的演变的假设具有深远的影响。此外，在所有描述的现存属中，只有不到一半的样本被用于分子系统学，一些对理解骨骼进化至关重要的分类群仍然缺失。因此，迫切需要增加分类单元的采样，以进行这一组的分子系统学研究。然而，由于它们的栖息地偏远，而且博物馆材料往往保存得很差，对目前已知的所有126个现存属进行排序将很难实现。因此，利用形态数据将未排序的类群合并到一个综合的系统学框架中是很有希望的，但不清楚哪种方法最适合这项任务。在这里，我们将先前建立的四个分子标记(18S、28S和16S核糖体DNA，以及细胞色素氧化酶亚基I)的分类样本增加了12个属，首次包括了Aulocalycoid目和Dactyloalyidae模式属的代表，这些分类群是理解六角形体平面进化的关键。系统发育分析表明，Aulocalycoida是二系的，并进一步支持六翼目的Parparly；因此，这些目从Linnean分类中被废除。我们进一步组装了形态特征矩阵，以最大简约(MP)、最大似然(ML)、贝叶斯和基于形态的分类框架将迄今未测序的属整合到系统发育分析中。我们发现，在这四种方法中，使用MP的全证据分析与现有的系统发育和分类假说的一致性给出了最可信的结果，而其他方法，特别是ML和Bning，表现得更差。我们使用我们现存的所有玻璃海绵属的全证据系统学来重建MP和ML框架中的形态特征的祖先状态，获得了对主要六角形体平面和其他特征(如不同的针状体类型)的进化的新的见解。我们的研究展示了如何利用分子和形态数据的综合方法来实现较大分类群的全面的、尽管在某些部分是临时的系统发育，以及如何将其用作理解表型进化的基础。这里提供的数据集和相关树旨在作为未来玻璃海绵进化工作的资源和起点。本文的在线版本(doi：10.1186/s12983-0170191-3)包含补充材料，授权用户可以使用。
Glass sponges (Class Hexactinellida) are important components of deep-sea ecosystems and are of interest from geological and materials science perspectives. The reconstruction of their phylogeny with molecular data has only recently begun and shows a better agreement with morphology-based systematics than is typical for other sponge groups, likely because of a greater number of informative morphological characters. However, inconsistencies remain that have far-reaching implications for hypotheses about the evolution of their major skeletal construction types (body plans). Furthermore, less than half of all described extant genera have been sampled for molecular systematics, and several taxa important for understanding skeletal evolution are still missing. Increased taxon sampling for molecular phylogenetics of this group is therefore urgently needed. However, due to their remote habitat and often poorly preserved museum material, sequencing all 126 currently recognized extant genera will be difficult to achieve. Utilizing morphological data to incorporate unsequenced taxa into an integrative systematics framework therefore holds great promise, but it is unclear which methodological approach best suits this task. Here, we increase the taxon sampling of four previously established molecular markers (18S, 28S, and 16S ribosomal DNA, as well as cytochrome oxidase subunit I) by 12 genera, for the first time including representatives of the order Aulocalycoida and the type genus of Dactylocalycidae, taxa that are key to understanding hexactinellid body plan evolution. Phylogenetic analyses suggest that Aulocalycoida is diphyletic and provide further support for the paraphyly of order Hexactinosida; hence these orders are abolished from the Linnean classification. We further assembled morphological character matrices to integrate so far unsequenced genera into phylogenetic analyses in maximum parsimony (MP), maximum likelihood (ML), Bayesian, and morphology-based binning frameworks. We find that of these four approaches, total-evidence analysis using MP gave the most plausible results concerning congruence with existing phylogenetic and taxonomic hypotheses, whereas the other methods, especially ML and binning, performed more poorly. We use our total-evidence phylogeny of all extant glass sponge genera for ancestral state reconstruction of morphological characters in MP and ML frameworks, gaining new insights into the evolution of major hexactinellid body plans and other characters such as different spicule types. Our study demonstrates how a comprehensive, albeit in some parts provisional, phylogeny of a larger taxon can be achieved with an integrative approach utilizing molecular and morphological data, and how this can be used as a basis for understanding phenotypic evolution. The datasets and associated trees presented here are intended as a resource and starting point for future work on glass sponge evolution. The online version of this article (doi:10.1186/s12983-017-0191-3) contains supplementary material, which is available to authorized users.