Kashimoto Rio, Tanimoto Miyako, Miura Saori, Satoh Noriyuki, Laudet Vincent, Khalturin Konstantin
Marine Eco-Evo-Devo Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan.
Marine Genomics Unit. Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan.
Zoolog Sci. 2022 Aug;39(4). doi: 10.2108/zs210111.
The relationship between anemonefish and sea anemones is one of the most emblematic examples of mutualistic symbiosis in coral reefs. Although this is a textbook example, the major aspects of this symbiosis are still not fully understood in mechanistic terms. Moreover, since studies of this relationship have usually been focused on anemonefish, much less is known about giant sea anemones, their similarities, their phylogenetic relationships, and their differences at the molecular level. Since both partners of the symbiotic relationship are important, we decided to explore this well-known phenomenon from the perspective of giant sea anemones. Here, we report reference transcriptomes for all seven species of giant sea anemones that inhabit fringing reefs of Okinawa (Japan) and serve as hosts for six species of local anemonefish. Transcriptomes were used to investigate their phylogenetic relations, genetic differences and repertoires of nematocyte-specific proteins. Our data support the presence of three distinct groups corresponding to three genera: , , and . The basal position among the three groups belongs to , which was the first to diverge from a common ancestor. While the magnitude of genetic difference between the representatives of and is large, intra-specific variation within is much smaller and seems to result from recent speciation events. Our data reconfirms that belongs to the genus , despite an overall morphological similarity with representatives of the genus . The availability of reference transcriptomes will facilitate further research into the fascinating relationship between sea anemones and anemonefish.
海葵鱼与海葵之间的关系是珊瑚礁中互利共生最具代表性的例子之一。尽管这是一个教科书式的例子，但这种共生关系的主要方面在机制层面仍未得到充分理解。此外，由于对这种关系的研究通常集中在海葵鱼上，对于巨型海葵及其相似性、系统发育关系以及在分子水平上的差异了解得要少得多。由于共生关系的双方都很重要，我们决定从巨型海葵的角度来探索这一著名现象。在这里，我们报告了栖息在日本冲绳沿岸珊瑚礁并作为六种当地海葵鱼宿主的所有七种巨型海葵的参考转录组。转录组被用于研究它们的系统发育关系、遗传差异以及刺细胞特异性蛋白的组成。我们的数据支持存在对应于三个属的三个不同类群： 、 和 。这三个类群中的基部位置属于 ，它是第一个从共同祖先分化出来的。虽然 和 的代表之间的遗传差异程度很大，但 内的种内变异要小得多，似乎是由近期的物种形成事件导致的。我们的数据再次证实 属于 属，尽管它在整体形态上与 属的代表相似。参考转录组的可用性将有助于进一步研究海葵与海葵鱼之间迷人的关系。
