Bell Tomoko, Iguchi Akira, Ohno Yoshikazu, Sakai Kazuhiko, Yokoyama Yusuke
Division of Science and Mathematics, Newman University, Wichita, KS 67213, USA.
Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8567, Japan.
R Soc Open Sci. 2025 Jan 22;12(1):232011. doi: 10.1098/rsos.232011. eCollection 2025 Jan.
Corals have been used as geochemical proxies since the 1970s, playing a prominent role in paleoceanography. However, it has not been well elucidated how aqueous ions sourced from seawater are transported and precipitated in coral skeletons. There are limited foundational methods to differentiate and quantify biogenic and abiogenic effects during skeletal formation. Especially, Mg in coral skeletons show individual variations suggesting large biogenic effects. Here, we evaluated biological complexity by investigating how coral genes evolved over geologic time scales. We focused on Mg transporter and analysed five species from genus and three species from genus . Mg transporter of , , and showed higher similarity to Mg transporter of vertebrates and were reported to appear on Earth during the Pleistocene. On the other hand, , s and showed lower or no similarity to vertebrates, and they were reported to appear on Earth before the Pleistocene. We suggest such evolutional records can be evidence to demonstrate biological complexity of Mg transport from seawater. This might explain that Mg transport is subject to evolution and why Mg incorporated in coral skeletons tends to show strong biogenic effects compared with other elements.
自20世纪70年代以来，珊瑚就被用作地球化学指标，在古海洋学中发挥着重要作用。然而，来自海水的水合离子是如何在珊瑚骨骼中运输和沉淀的，目前尚未得到充分阐明。在骨骼形成过程中，区分和量化生物成因和非生物成因影响的基础方法有限。特别是，珊瑚骨骼中的镁表现出个体差异，表明存在较大的生物成因影响。在这里，我们通过研究珊瑚基因在地质时间尺度上的进化来评估生物复杂性。我们聚焦于镁转运蛋白，分析了来自 属的五个物种和来自 属的三个物种。 、 、 和 的镁转运蛋白与脊椎动物的镁转运蛋白具有更高的相似性，据报道它们在更新世出现在地球上。另一方面， 、 和 与脊椎动物的相似性较低或没有相似性，据报道它们在更新世之前出现在地球上。我们认为，这种进化记录可以作为证明从海水中运输镁的生物复杂性的证据。这可能解释了镁的运输受到进化影响的原因，以及为什么与其他元素相比，纳入珊瑚骨骼中的镁往往表现出强烈的生物成因影响。
