Details

Autor(en) / Beteiligte

• LaJeunesse, Todd C.
• Parkinson, John Everett
• Gabrielson, Paul W.
• Jeong, Hae Jin
• Reimer, James Davis
• Voolstra, Christian R.
• Santos, Scott R.

Titel

Systematic Revision of Symbiodiniaceae Highlights the Antiquity and Diversity of Coral Endosymbionts

Ist Teil von

• Current biology, 2018-08, Vol.28 (16), p.2570-2580.e6

Ort / Verlag

England: Elsevier Inc

Erscheinungsjahr

2018

Link zum Volltext

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• 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 a major 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 (∼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. •The micro-algal genus Symbiodinium is split into multiple genera•Seven of these genera are formally described based on genetics and ecology•Dinoflagellates in the family Symbiodiniaceae originated in the Jurassic Period•Symbiodiniaceae diversification coincided with the radiation of reef-building corals Symbiodinium are micro-algal symbionts of reef-building corals. LaJeunesse et al. report new estimates from molecular dating, indicating that corals and Symbiodinium originated and diversified together ∼140–200 mya. Divergent Symbiodinium “clades” are now partitioned into multiple genera, better reflecting their long evolutionary history.