Bronstein Omri, Kroh Andreas, Haring Elisabeth
Natural History Museum Vienna, Geological-Paleontological Department, Burgring 7, 1010 Vienna, Austria; Natural History Museum Vienna, Central Research Laboratories, Burgring 7, 1010 Vienna, Austria; The Steinhardt Museum of Natural History and National Research Centre, Tel Aviv University, Israel.
Natural History Museum Vienna, Geological-Paleontological Department, Burgring 7, 1010 Vienna, Austria.
Mol Phylogenet Evol. 2016 Nov;104:1-13. doi: 10.1016/j.ympev.2016.07.028. Epub 2016 Jul 27.
Novel COI and bindin sequences of the Red Sea collector echinoid Tripneustes gratilla elatensis are used to show that (1) discordance between mitochondrial and nuclear loci exists in this echinoid genus, (2) Tripneustes gratilla as currently defined possibly comprises a complex of cryptic species, and (3) Red Sea Tripneustes form a genetically distinct clade in the bindin tree, which diverged from other Tripneustes clades at least 2-4million years ago. Morphological reassessment of T. gratilla elatensis shows perfect congruence between identification based on skeletal features and genetic data based on a nuclear marker sequence. Hence the Red Sea Tripneustes subspecies established by Dafni in 1983 is a distinct biological unit. All T. g. elatensis samples analyzed are highly similar to or share mtDNA haplotypes with Philippine T. g. gratilla, as do representatives from other edge-of-range occurrences. This lack of genetic structure in Indo-Pacific Tripneustes is interpreted as a result of wide-spread mitochondrial introgression. New fossil specimens from the Red Sea area confirm the sympatric occurrence of T. g. elatensis and T. g. gratilla in the northern Red Sea during Late Pleistocene, identifying a possible timing for the introgression. In addition, present-day distribution shows a contact zone in the Southern Red Sea (in the Dahlak Archipelago). T. g. elatensis, is yet another example of a Red Sea taxon historically identified as conspecific with its Indo-Pacific relatives, but which turned out to be a morphologically and genetically distinct endemic taxon, suggesting that the level of endemism in the Red Sea may still be underestimated.
红海采集的海胆类动物细雕刻肋海胆（Tripneustes gratilla elatensis）的新型COI和结合蛋白序列用于表明：（1）该海胆类动物属中线粒体和核基因座之间存在不一致性；（2）当前定义的细雕刻肋海胆可能包含一个隐存种复合体；（3）红海细雕刻肋海胆在结合蛋白树中形成一个遗传上不同的进化枝，该进化枝至少在200 - 400万年前就与其他细雕刻肋海胆进化枝分化开来。对细雕刻肋海胆的形态学重新评估表明，基于骨骼特征的鉴定与基于核标记序列的遗传数据完全一致。因此，达夫尼于1983年建立的红海细雕刻肋海胆亚种是一个独特的生物单元。所有分析的细雕刻肋海胆样本与菲律宾的细雕刻肋海胆高度相似或共享线粒体DNA单倍型，其他分布范围边缘地区的代表样本也是如此。印度 - 太平洋地区细雕刻肋海胆缺乏遗传结构被解释为广泛的线粒体基因渗入的结果。来自红海地区的新化石标本证实了在晚更新世期间，细雕刻肋海胆和细雕刻肋海胆在红海北部同域出现，确定了可能的基因渗入时间。此外，现今的分布显示在红海南部（达拉克群岛）存在一个接触带。细雕刻肋海胆是另一个历史上被认为与其印度 - 太平洋亲属同种，但后来被证明是形态和遗传上不同的特有分类单元的红海分类群的例子，这表明红海的特有程度可能仍被低估。
