Hawai'i Institute of Marine Biology, School of Ocean and Earth Science and Technology, University of Hawai'i, Kāne'ohe, Hawai'i, United States of America.
PLoS One. 2011 Jan 5;6(1):e15854. doi: 10.1371/journal.pone.0015854.
Endosymbiotic dinoflagellates in the genus Symbiodinium are fundamentally important to the biology of scleractinian corals, as well as to a variety of other marine organisms. The genus Symbiodinium is genetically and functionally diverse and the taxonomic nature of the union between Symbiodinium and corals is implicated as a key trait determining the environmental tolerance of the symbiosis. Surprisingly, the question of how Symbiodinium diversity partitions within a species across spatial scales of meters to kilometers has received little attention, but is important to understanding the intrinsic biological scope of a given coral population and adaptations to the local environment. Here we address this gap by describing the Symbiodinium ITS2 sequence assemblages recovered from colonies of the reef building coral Montipora capitata sampled across Kāne'ohe Bay, Hawai'i. A total of 52 corals were sampled in a nested design of Coral Colony(Site(Region)) reflecting spatial scales of meters to kilometers. A diversity of Symbiodinium ITS2 sequences was recovered with the majority of variance partitioning at the level of the Coral Colony. To confirm this result, the Symbiodinium ITS2 sequence diversity in six M. capitata colonies were analyzed in much greater depth with 35 to 55 clones per colony. The ITS2 sequences and quantitative composition recovered from these colonies varied significantly, indicating that each coral hosted a different assemblage of Symbiodinium. The diversity of Symbiodinium ITS2 sequence assemblages retrieved from individual colonies of M. capitata here highlights the problems inherent in interpreting multi-copy and intra-genomically variable molecular markers, and serves as a context for discussing the utility and biological relevance of assigning species names based on Symbiodinium ITS2 genotyping.
内共生甲藻属中的共生甲藻对石珊瑚的生物学以及各种其他海洋生物都至关重要。共生甲藻属在遗传和功能上具有多样性，共生甲藻与珊瑚的共生关系的分类性质被认为是决定共生体环境耐受性的关键特征。令人惊讶的是，共生甲藻多样性如何在米到公里的空间尺度内在一个物种内分配的问题很少受到关注，但对于理解给定珊瑚种群的内在生物学范围以及对当地环境的适应至关重要。在这里，我们通过描述从夏威夷卡内奥赫湾的造礁珊瑚 Montipora capitata 采集的珊瑚群中回收的共生甲藻 ITS2 序列组合来解决这一差距。在反映米到公里空间尺度的珊瑚群（地点（区域））嵌套设计中，共采集了 52 个珊瑚。回收了多种共生甲藻 ITS2 序列，大部分方差分配在珊瑚群一级。为了确认这一结果，对六个 M. capitata 珊瑚群中的共生甲藻 ITS2 序列多样性进行了更深入的分析，每个珊瑚群有 35 到 55 个克隆。从这些珊瑚群中回收的 ITS2 序列和定量组成差异显著，表明每个珊瑚都含有不同的共生甲藻组合。从 M. capitata 的单个珊瑚群中回收的共生甲藻 ITS2 序列组合的多样性突出了解释多拷贝和基因组内可变分子标记所固有的问题，并为讨论基于共生甲藻 ITS2 基因分型分配物种名称的效用和生物学相关性提供了背景。
