Systematic Revision of Symbiodiniaceae Highlights the Antiquity and Diversity of Coral Endosymbionts
Systematic Revision of Symbiodiniaceae Highlights the Antiquity and Diversity of Coral Endosymbionts
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DOI：
10.1016/j.cub.2018.07.008
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发表时间：
2018-08-20
期刊：
影响因子：
9.2
通讯作者：
Santos, Scott R.
中科院分区：
文献类型：
--
作者：
LaJeunesse, Todd C.;Parkinson, John Everett;Santos, Scott R.
分子数据的出现改变了组织和研究地球生命的科学。基于遗传学的证据为许多生物系统的多样性、生态学和起源提供了基本的见解，包括后生动物宿主与其微藻伙伴之间的互惠关系。一个著名的例子是驱动石珊瑚和珊瑚礁生态系统生长的甲藻内共生体（“虫黄藻”）。一旦假设包括一个单一的panmictic物种，遗传证据显示了分歧和丰富的多样性zooxanthella属共生藻。尽管几十年来一直在报道这种多样性的重要性，但这些真核微生物的正式系统学并没有跟上步伐，而且早就应该进行重大修订。考虑到分子，形态，生理和生态数据，我们提出，进化分歧共生藻“分支”相当于属在共生藻科，我们提供了正式的描述，其中七个。此外，我们重新校准了该群体的分子钟，并将该家族最早多样化的日期修改为中生代中期（类似于1.6亿年）。这个时间对应于适应性辐射的类似物，现代浅水石珊瑚在侏罗纪时期，并连接这些共生的腰鞭毛虫的出现和进化成功的造礁珊瑚的崛起。这种改进的框架承认共生藻科的漫长的进化历史，同时填补了一个明显的分类空白。它的采用将促进科学对话和未来对这些重要微藻的生理学，生态学和进化的研究。
The advent of molecular data has transformed the science of organizing and studying life on Earth. Genetics-based evidence provides fundamental insights into the diversity, ecology, and origins of many biological systems, including the mutualisms between metazoan hosts and their micro-algal partners. A well-known example is the dinoflagellate endosymbionts ("zooxanthellae'') that power the growth of stony corals and coral reef ecosystems. Once assumed to encompass a single panmictic species, genetic evidence has revealed a divergent and rich diversity within the zooxanthella genus Symbiodinium. Despite decades of reporting on the significance of this diversity, the formal systematics of these eukaryotic microbes have not kept pace, and amajor revision is long overdue. With the consideration of molecular, morphological, physiological, and ecological data, we propose that evolutionarily divergent Symbiodinium "clades'' are equivalent to genera in the family Symbiodiniaceae, and we provide formal descriptions for seven of them. Additionally, we recalibrate the molecular clock for the group and amend the date for the earliest diversification of this family to the middle of the Mesozoic Era (similar to 160 mya). This timing corresponds with the adaptive radiation of analogs to modern shallow-water stony corals during the Jurassic Period and connects the rise of these symbiotic dinoflagellates with the emergence and evolutionary success of reef-building corals. This improved framework acknowledges the Symbiodiniaceae's long evolutionary history while filling a pronounced taxonomic gap. Its adoption will facilitate scientific dialog and future research on the physiology, ecology, and evolution of these important micro-algae.