Department of Biological Science and Technology, Tokyo University of Science.
Genes Genet Syst. 2020 Jul 8;95(2):55-63. doi: 10.1266/ggs.19-00054. Epub 2020 Apr 18.
In closed sea areas such as Tokyo Bay, a phenomenon known as a green tide often occurs, in which large amounts of Ulva seaweed grow abnormally and form mats along the coast. This is currently a serious environmental problem. Green tides are generated by the explosive growth of multiple types of Ulva algae. However, many Ulva species show similar characteristics to each other and are indistinguishable by appearance, making it difficult to identify the Ulva algae in green tides. In this study, we determined the entire nucleotide sequence of the chloroplast genome of Ulva pertusa (syn. Ulva australis) and identified two large inversions of gene order, suggesting the occurrence of genome inversions. We also detected structural polymorphisms among Ulva chloroplast genomes. Ulva pertusa was classified in a different clade from that containing U. lactuca and U. ohnoi, suggesting that U. pertusa is evolutionarily divergent from these species. Based on this knowledge, we constructed a genetic diagnosis system for Ulva algae. Using this approach, we established a simple method that can determine the species of Ulva algae by PCR using specific molecular markers, through which representative Ulva species such as U. lactuca, U. ohnoi and U. pertusa were easily distinguished.
在东京湾等封闭海域，经常会出现一种称为绿潮的现象，大量的石莼属海藻异常生长，并在沿海形成垫状。这是目前一个严重的环境问题。绿潮是由多种石莼属藻类的爆发性生长引起的。然而，许多石莼属物种彼此之间表现出相似的特征，仅凭外观无法区分，因此很难识别绿潮中的石莼属藻类。在这项研究中，我们确定了石莼（原学名为 U. australis）叶绿体基因组的完整核苷酸序列，并鉴定出两个基因顺序的大型倒位，表明发生了基因组倒位。我们还检测到了石莼属叶绿体基因组之间的结构多态性。石莼属被分类为与 U. lactuca 和 U. ohnoi 不同的分支，表明石莼属与这些物种在进化上存在差异。基于这些知识，我们构建了一个石莼属藻类的遗传诊断系统。利用这种方法，我们建立了一种简单的 PCR 方法，通过使用特定的分子标记，可以确定石莼属藻类的种类，通过这种方法可以轻松区分 U. lactuca、U. ohnoi 和 U. pertusa 等代表性石莼属物种。
