Nuclear and Mitochondrial Gene Data Support Recent Radiation within the Sea Spider Species Complex Pallenopsis patagonica
Nuclear and Mitochondrial Gene Data Support Recent Radiation within the Sea Spider Species Complex Pallenopsis patagonica
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DOI：
10.3389/fevo.2016.00139
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发表时间：
2017-01-04
影响因子：
3
通讯作者：
Leese, Florian
中科院分区：
文献类型：
--
作者：
Doemel, Jana S.;Melzer, Roland R.;Leese, Florian
南极大陆架的气候历史在进化时间尺度上形成了多样化的底栖生态系统。动物区系多样性的程度直到最近才被揭示，特别是通过使用遗传数据。除了新报告的物种外，南大洋已知的底栖无脊椎动物物种实际上是代表遗传上非常独特的进化枝的物种复合体。先前的研究表明，海蜘蛛Pallenopsis patagonica就是这样一个由几个不同的线粒体进化枝组成的物种复合体。然而，对另一种海蜘蛛复合体 Colossendeis megalonyx 的遗传分析表明，仅观察一个线粒体基因可能会导致对物种复合体内物种数量的高估，并揭示线粒体核不一致。在这项研究中，我们不仅添加了来自巴塔哥尼亚、亚南极洲和东威德尔海的样本，还添加了核内转录间隔区（ITS）区域的序列数据，以扩展巴塔哥尼亚现有的数据集，以获得有关该物种复合体的更多信息。事实上，在观察核数据时，不同进化枝的数量减少了，但没有线粒体核不一致的情况，因此没有证据表明不同线粒体进化枝之间存在杂交和物种形成逆转事件，如 C. megalonyx 中那样。由于 P. patagonica 和 C. megalonyx 中线粒体 COI 多样性和分化的模式非常相似，并且对两个物种复合体的分子测年分析表明最近更新世期间进化枝的分离，不同的生物过程似乎导致了 P. patagonica 中快速和稳定的物种边界，而不是 C. megalonyx，后者甚至在主要线粒体谱系之间杂交。 发生了。
The climate history of the Antarctic continental shelf has formed a diverse benthic ecosystem over evolutionary time scales. The extent of faunal diversity has only recently been unveiled especially by using genetic data. In addition to newly reported species, known species of benthic invertebrates in the Southern Ocean turned out to be in fact species complexes representing genetically very distinct clades. Previous studies have shown that the sea spider Pallenopsis patagonica is such a species complex consisting of several divergent mitochondrial clades. However, genetic analyses of another sea spider complex, Colossendeis megalonyx, showed that looking at one mitochondrial gene only can lead to overestimation of species number within a species complex and revealed mito-nuclear discordances. In this study we expand the current data set of P. patagonica by adding not only samples from Patagonia, the Subantarctic and the Eastern Weddell Sea, but also sequence data for the nuclear internal transcribed spacer (ITS) region to obtain more information about the species complex. In fact, the number of distinct clades is reduced when looking at nuclear data, but there are no cases of mito-nuclear discordance and hence no evidence for hybridization and speciation reversal events between divergent mitochondrial clades as in C. megalonyx. As patterns of mitochondrial COI diversity and divergence within P. patagonica and C. megalonyx are very similar and molecular dating analyses of both species complexes suggest a recent separation of clades during the Pleistocene, different biological processes seem to have led to fast and stable species boundaries in P. patagonica as opposed to C. megalonyx where hybridization even across major mitochondrial lineages occured.