DeLeo Danielle M, Bessho-Uehara Manabu, Haddock Steven H D, McFadden Catherine S, Quattrini Andrea M
Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Department of Biological Sciences, Institute of Environment, Florida International University, Miami, FL, USA.
Proc Biol Sci. 2024 Apr 30;291(2021):20232626. doi: 10.1098/rspb.2023.2626. Epub 2024 Apr 24.
Bioluminescence is a widespread phenomenon that has evolved multiple times across the tree of life, converging among diverse fauna and habitat types. The ubiquity of bioluminescence, particularly in marine environments where it is commonly used for communication and defense, highlights the adaptive value of this trait, though the evolutionary origins and timing of emergence remain elusive for a majority of luminous organisms. Anthozoan cnidarians are a diverse group of animals with numerous bioluminescent species found throughout the world's oceans, from shallow waters to the light-limited deep sea where bioluminescence is particularly prominent. This study documents the presence of bioluminescent Anthozoa across depth and explores the diversity and evolutionary origins of bioluminescence among Octocorallia-a major anthozoan group of marine luminous organisms. Using a phylogenomic approach and ancestral state reconstruction, we provide evidence for a single origin of bioluminescence in Octocorallia and infer the age of occurrence to around the Cambrian era, approximately 540 Ma-setting a new record for the earliest timing of emergence of bioluminescence in the marine environment. Our results further suggest this trait was largely maintained in descendants of a deep-water ancestor and bioluminescent capabilities may have facilitated anthozoan diversification in the deep sea.
生物发光是一种广泛存在的现象，在生命之树上已经多次进化，在不同的动物群和栖息地类型中趋同。生物发光的普遍性，特别是在海洋环境中，它常用于交流和防御，凸显了这一特征的适应性价值，尽管对于大多数发光生物来说，其进化起源和出现时间仍然难以捉摸。珊瑚虫纲动物是一类多样的动物，在世界各大洋中发现了许多生物发光物种，从浅水区到生物发光特别突出的光线有限的深海。本研究记录了不同深度生物发光珊瑚虫纲动物的存在情况，并探讨了八放珊瑚亚纲（海洋发光生物的一个主要珊瑚虫纲类群）中生物发光的多样性和进化起源。通过系统基因组学方法和祖先状态重建，我们提供了八放珊瑚亚纲生物发光单一起源的证据，并推断其出现时间约为寒武纪时期，大约5.4亿年前——创造了海洋环境中生物发光最早出现时间的新纪录。我们的结果进一步表明，这一特征在深水祖先的后代中基本得以保留，生物发光能力可能促进了深海珊瑚虫纲动物的多样化。
