潮间带腹足类对环境变化的代谢响应机制比较研究

The intertidal ecosystem is one of the most threatened ecosystems in the scenario of global change. Intertidal animals that undergo alternating periods of immersion in water and exposure to air have to face changes in food composition and quality, increased temperature stress and variation of air exposure duration. Although all intertidal animals face a set of common stresses, not all species are equally likely to suffer from these stresses. Thus, it is important to identify the types of physiological variation that may cause some species to be more (or less) sensitive than other species...Intertidal limpets provide an excellent study system for examining this type of interspecific variation in sensitivity to environmental change. The fossil record indicates highly selective extinctions occurred among intertidal animals, and the selective extinction may be closely related to the metabolic and ecologic characters of the species. Therefore, the capabilities of physiological adaptations play fundamental roles in animals against environmental changes. To understand-and predict-species' shifts and community dynamics in the scenario of global change, the core challenge is to clearly know the physiological adaptation of keystone species to environmental changes. . Oxygen- and capability-limited thermal tolerance theory (OCLTT) can quantitatively analyze the ecological significance of environmental changes by integrating metabolism, stress protein defenses and ecological fitness. AMP-activated kinase (AMPK) and silent mating-type information regulation 2 homologue 1 (SIRT1) are two metabolic sensors that play crucial roles in controlling cellular energy metabolism. The integration of OCLTT and molecular markers should be very useful for elucidating animals' metabolic adaptations in the face of environmental changes..Some intertidal limpets are keystone species in the intertidal ecosystem. Nipponacmea schrenckii, Cellana toreuma and Siphonaria japonica, with similar niches, are important consumers along China coast, and their respiratory organs are ctenidia, pallial gill and lung, respectively, indicating these species have different evolutionary history and differentiation in metabolic regulation. In the scenario of global change, these three species should have different response and species' dynamics..In the present project, we try to investigate the inter-species difference of physiological adaptations against environmental changes among three intertidal limpets with similar niches but respiratory organs by using OCLTT and molecular markers. This project should be important in understanding the species dynamics and the mechanisms of selective extinctions in the intertidal ecosystem.

作为生物圈最为脆弱的系统之一，潮间带生态系统是研究气候变化对生态系统影响的理想系统。化石证据表明，潮间带腹足类在地质历史时期存在选择性物种灭绝现象，而生理适应机制的差异可能是导致这一选择性效应的重要原因。为了解在全球变化背景下潮间带生物群落动态和选择性灭绝的内在机理，本项目拟以三种具有相似生态位但呼吸模式不同的潮间带常见腹足类为研究对象，以氧限制热耐受理论为理论基础，结合与代谢相关的分子标记(腺苷酸活化蛋白激酶,AMPK和沉默信息调节因子2相关酶1,SIRT1)，通过测定三种腹足类对环境变化（食物组成和质量、温度胁迫上升和干露时间变化）的生理适应机理，比较种间差异，从生理学角度分析全球变化背景下潮间带腹足类选择性灭绝的内在机理。

作为生物圈最为脆弱的系统之一，潮间带生态系统是研究气候变化对生态系统影响的理想系统。化石证据表明，潮间带腹足类在地质历史时期存在选择性物种灭绝现象，而生理适应机制的差异可能是导致这一选择性效应的重要原因。为了解在全球变化背景下潮间带生物群落动态和选择性灭绝的内在机理，项目组以三种具有相似生态位但呼吸模式不同的潮间带常见腹足类为研究对象，对潮间带腹足类的生理适应机制和系统地理格局进行了深入地研究，取得了一系列创新性的成果。在生理生态学方面，以能量代谢为主线，整合心率、蛋白损伤和基因表达等数据，较为系统地分析了潮间带腹足类对环境因子的耐受阈值及其生理和分子调节，阐明了潮间带生物对环境因子的生理适应机制。利用这一生理机制模型，项目组研究了多重环境胁迫对野外种群的影响。结果表明，多因子耦合作用会显著增加生理胁迫强度，在高温和降水共同影响下，潮间带生物在夏季面临着多重环境压力，气候变化所带来的温度升高和降水量变化会加剧潮间带生物所面临威胁。项目组进一步分析了潮间带生物对气候变化的敏感性及其纬度特征。结果表明，在东亚地区，温带、亚热带和热带潮间带腹足类种群间在温度安全边界和能量代谢调节机制上存在差异，亚热带种群温度安全边界更窄，更容易受到气候变化的影响。在系统地理学方面，查明了嫁（虫戚）、日本菊花螺和背尖贝属帽贝在中国及东南亚沿岸的系统地理格局。研究发现潮间带生物形成了东北亚和东南亚分支，在我国沿岸，潮间带生物形成了以长江口为界的地理隔离，长江冲淡水、底质类型、海流和气候等因素对于隔离的形成起到重要作用。本项目通过研究潮间带生物对环境变化的生理适应机理，分析气候变化和人类活动对潮间带生物多样性及生物地理格局的影响，为阐明潮间带生态系统对气候变化和人类活动的响应提供理论基础。在项目支持下，目前已发表SCI收录论文14篇；获得国家发明专利2项；培养博士后1名，博士研究生6名，硕士研究生5名；邀请外国专家进行学术交流6人次；在厦门大学组织国际学术研讨会2次；参加国内外会议24次。