Center for Northeast Asian Studies, Tohoku University, 41 Kawauchi, Aoba-ku, Sendai, Miyagi, 980-8576, Japan.
Graduate School of Life Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577, Japan.
Sci Rep. 2022 Feb 8;12(1):2119. doi: 10.1038/s41598-022-05026-z.
Molecular studies based on the high resolution genetic markers help us to grasp the factor shaping the genetic structure of marine organisms. Ecological factors linking to life history traits have often explained the process of genetic structuring in open and connectable oceanic environments. Besides, population genetic divergence can be affected by fragmented habitat, oceanic current, and past geographical events. In the present study, we demonstrated the genetic differentiation of marine gastropod Monodonta sp. within a narrow range of peripheral oceanic islands, the Ogasawara Islands. Genetic analyses were performed not only with a mitochondrial DNA marker but also with a high-throughput SNPs dataset obtained by ddRAD-seq. The results of the mtDNA analyses did not show genetic divergence among populations, while the SNPs dataset detected population genetic differentiation. Population demographic analyses and gene flow estimation suggested that the genetic structure was formed by sea level fluctuation associated with the past climatic change and regulated by temporal oceanographic conditions. These findings provide important insights into population genetic patterns in open and connectable environments.
基于高分辨率遗传标记的分子研究有助于我们了解塑造海洋生物遗传结构的因素。与生活史特征相关的生态因素常常可以解释在开放和可连接的海洋环境中遗传结构形成的过程。此外，栖息地的碎片化、洋流和过去的地理事件也会影响种群遗传分化。在本研究中，我们展示了在小范围的外围海洋岛屿，小笠原群岛内，海洋腹足纲动物单齿螺属（Monodonta sp.）的遗传分化。遗传分析不仅使用了线粒体 DNA 标记，还使用了通过 ddRAD-seq 获得的高通量 SNPs 数据集。mtDNA 分析的结果并未显示种群间的遗传分化，而 SNPs 数据集则检测到了种群遗传分化。种群动态分析和基因流动估计表明，遗传结构是由海平面波动形成的，这种波动与过去的气候变化有关，并受时间海洋条件的调节。这些发现为开放和可连接环境中的种群遗传模式提供了重要的见解。
