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

珊瑚礁生物和栖息地面临着越来越多的应激因素，其影响越来越受到监测和研究。人们对潜在的遗传学知之甚少，遗传学是物种适应并坚持度过其中一些环境变化的进化工具。这项研究的目的是通过检查多种珊瑚礁鱼类物种的特殊遗传特征，确定在一个物种范围内不同种群的局部适应潜力是否不同。研究人员将比较处于物种范围中心的鱼类种群和处于物种范围边缘的鱼类种群，以测试外围栖息地是否可以作为拥有更大适应潜力的种群的区域。在这个项目中，日本温带珊瑚礁北部山脉边界的鱼类种群将与菲律宾和印度尼西亚热带珊瑚礁北部山脉中心的鱼类种群进行比较。这项研究旨在增加对边缘种群在当地适应和物种形成中的作用的了解，并获得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的分子生物学家詹姆斯·雷默博士的指导下进行。Remer博士在该区域海洋系统的种群遗传学方面拥有宝贵的经验和洞察力，并提供关键野外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，随后提取DNA，测序，最后进行分析。研究物种的选择部分是基于它们的分布位置和大小、繁殖方式和远洋幼虫的持续时间。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中的潜在模式。本研究期间收集的样本将与之前收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种群和外围种群之间的遗传变异水平和选择基因的频率。这项研究的发现将有助于回答这些珊瑚礁鱼在同一物种范围内的种群之间是否有不同的适应潜力的特定指标。然后可以进行进一步的研究，以更好地了解物种形成、局部适应、快速进化的机制，以及提高未来对珊瑚礁健康的预测的准确性。该奖项根据东亚和太平洋夏季学院计划，支持一名美国研究生的暑期研究，由NSF和日本科学促进会共同资助。

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.