EAPSI: Investigating the Role of Peripheral Habitats in the Adaptive Potential of Coral Reef Fishes

珊瑚礁生物和生境面临越来越多的压力，其影响日益受到监测和研究。人们对潜在的遗传学知之甚少，而遗传学是物种适应并在这些环境变化中生存的进化工具。本研究的目的是通过研究多个珊瑚礁鱼类物种的特定遗传特征，确定一个物种范围内不同种群的当地适应潜力是否不同。研究人员将比较物种范围中心的鱼类种群和物种范围边缘的鱼类种群，以测试周边栖息地是否可以作为具有更大适应潜力的种群的栖息地。在本项目中，将把日本温带珊瑚礁北方分布区边界的鱼类种群与菲律宾和印度尼西亚热带珊瑚礁分布区中心的种群进行比较。这项研究旨在加深对边缘种群在当地适应和物种形成中的作用的了解，并获取信息以更好地预测这些物种对气候和环境变化的脆弱性。这项研究将在琉球大学分子生物学家James Reimer博士的指导下进行。Reimer博士在该地区海洋系统的种群遗传学方面拥有宝贵的经验和见解，并提供关键现场设备和实验室技术的访问和指导。该项目将包括收集日本八种珊瑚礁鱼类的边缘种群样本，随后进行DNA提取，测序和最后分析。根据其分布地点和大小、繁殖方式和浮游幼虫持续时间，选择了部分研究物种。研究人员怀疑这些生活史特征会影响适应和物种形成的目标遗传指标的潜在模式。本研究期间采集的样本将与先前采集的菲律宾和印度尼西亚样本进行比较。利用两种种群类型的RAD测序产生的信息，研究人员将比较每个物种的中心和外围种群之间的遗传变异水平和基因频率。这项研究的结果将有助于回答这些适应潜力的特定指标是否在这些珊瑚鱼的物种范围内的种群之间存在差异。然后可以进行进一步的研究，以更好地了解物种形成，当地适应，快速进化的机制，以及提高未来预测珊瑚礁健康的准确性。该奖项是东亚和太平洋夏季研究所计划下的一个奖项，由美国国家科学基金会和日本科学促进会共同资助，支持美国研究生的夏季研究。

Coral reef organisms and habitats are faced with a growing number of stressors, the effects of which are increasingly monitored and studied. Less is understood about the underlying genetics, the evolutionary tools for species to adapt and persist through some of these environmental changes. This study aims to identify whether the potential for local adaptation differs across populations within a species range by examining particular genetic characteristics in multiple coral reef fish species. Researchers will compare between populations of fishes at the center of their species range and those at the edges of the species range to test whether peripheral habitats may serve as regions harboring populations with greater adaptive potential. For this project, fish populations at their northern range boundary in the temperate coral reefs of Japan will be compared to populations at the center of their ranges in the tropical reefs of the Philippines and Indonesia. This study aims to increase understanding about the role of edge populations in local adaptation and speciation as well as to gain information to better predict the vulnerability of these species to changes in climate and environment. This research will be conducted under the mentorship of molecular biologist, Dr. James Reimer at the University of the Ryukyus. Dr. Reimer has valuable experience and insight on the population genetics of the marine system in this region and provides access and instruction to key field equipment and laboratory techniques.This project will consist of the collection of the edge population samples for eight reef fish species in Japan, subsequent DNA extractions, sequencing and finally, analyses. Study species were chosen in part, based on their distribution location and size, reproductive mode, and pelagic larval duration. Researchers suspect that these life history characteristics influence potential patterns in the targeted genetic indicators of adaptation and speciation. Samples collected during this study will be compared with previously collected Philippine and Indonesian samples. Using information generated from RAD sequencing of both population types, researchers will compare levels of genetic variation and the frequency of genes under selection between center and peripheral populations of each species. The findings from this research will help to answer whether these particular indictors of adaptive potential differ between populations within a species range in these reef fish. Further studies can then be conducted to better understand mechanisms of speciation, local adaptation, rapid evolution, as well as to improve the accuracy of future predictions for coral reef health. This award, under the East Asia and Pacific Summer Institutes program, supports summer research by a U.S. graduate student and is jointly funded by NSF and the Japan Society for the Promotion of Science.