Collaborative Research: RUI: Transduction of Physiological Stress through Species Interactions: Indirect Effects of Climate Change

由于大气中温室气体浓度的增加，陆地和海洋的温度正在上升。 迄今为止，许多研究都集中在温度升高对动物的直接生理影响上。 然而，一个受到较少关注的重要领域是了解物种之间的相互作用将如何因变暖而发生变化。 该项目旨在描述一个易受气候变化影响的物种所经历的生理压力通过行为相互作用传递给第二个物种的程度，即使第二个物种本身并不容易受到气候变化的影响。 这项拟议的研究将揭示气候变化对生理健康的多方面性质，这是所有野生动物的一个重要问题，包括濒危和经济上重要的物种。本科生和研究生将参与这项工作的各个方面，接受重要的科学培训。此外，研究人员正在与中学教师合作，开发关于气候变化和海洋生物的教育模块，学校教室将被邀请到实地观察和参与科学研究。本研究将评估生理和物种相互作用对气候变化的反应，在一个模型系统的热生物学：一对同域潮间带瓷蟹物种（属岩蟹），不同的直接敏感性气候变化。 这两个物种一起出现在多岩石的太平洋海岸，但一个物种生活在温暖的中潮间带，另一个生活在较冷的低潮间带和潮下带。 由于每个物种的热性能和它们所经历的最高栖息地温度，中潮间带物种（竞争优势）比低潮间带物种（竞争从属）对温度升高更敏感。 该研究的中心假设是，温度上升可能会迫使中潮间带物种进入低潮间带栖息地，增加竞争相互作用，并导致低潮间带物种的行为压力增加。 这一假设将在三项关于自然栖息地螃蟹的研究中得到检验，一项是人工现场实验，另一项是实验室实验：（1）将在自然环境中测量螃蟹的热条件和分布，以确定温暖条件在多大程度上增加物种共存和竞争性相互作用的潜力。 (2)将进行一个操作性的现场实验，以测量在两个潮间带高度的螃蟹笼热应力的行为反应。 温度的变化将由放置在笼子里的螃蟹上的人造石头的厚度和成分来调节，否则情况会自然变化。 (3)实验性潮间带模拟槽将用于测试每种蟹对热应激的行为和生理反应。 加热灯将用于调节不同浸泡程度的石头下的温度。 在现场（2）和实验室（3）实验中，将分别和组合测试蟹种。 所有三项研究中的生理状况将使用现有的基因表达热应激生物标志物和生殖活性的卵黄蛋白测定从血淋巴（血液）样本中进行评估。 将使用NanoString nCounter平台（一种基于非扩增的mRNA直接测量方法）估计44种靶转录物和6种管家基因的基因表达水平。 将使用基于抗体的试验（ELISA）和可用抗体对卵母细胞的卵黄蛋白（卵黄蛋白）和血淋巴的卵黄蛋白前体（卵黄蛋白原）进行试验。

Temperatures on land and in the ocean are rising as a result of increased greenhouse gas concentrations in the atmosphere. Much research to date has focused on the direct physiological influence of rising temperatures on animals. However, an important area that has received less attention is to understand how species interactions will change as a result of warming. This project seeks to characterize the degree to which physiological stresses experienced by one species that is vulnerable to climate change are transduced to a second species through behavioral interactions, even if that second species is not itself vulnerable to climate change. The proposed research will uncover the multifaceted nature of climate change on physiological health, an important problem for all wildlife, including endangered and economically important species. Undergraduate and graduate students will be involved in all aspects of this work, receiving important scientific training. In addition, the researchers are teaming with secondary school teachers to develop educational modules on climate change and ocean life, and school classrooms will be invited to field sites to observe and participate in scientific research. This research will assess physiological and species interaction responses to climate change in a model system for thermal biology: a pair of sympatric intertidal zone porcelain crab species (genus Petrolisthes) that differ in their direct susceptibility to climate change. Both species occur together on rocky Pacific shores but one species lives in the warmer mid-intertidal zone and the other in the cooler low-intertidal and subtidal zones. The mid-intertidal species (the competitive dominant) is more sensitive to rising temperatures than the low-intertidal species (the competitive subordinate) due to the thermal performance of each species and the maximal habitat temperatures they experience. The central hypothesis of the study is that rising temperatures will likely force the mid-intertidal species into the low-intertidal habitat, increasing competitive interactions and causing increased behavioral stress to the low-intertidal species. That hypothesis will be tested in three studies of crabs in the natural habitat, a manipulated field experiment, and a laboratory experiment: (1) Thermal conditions and distributions of crabs will be measured in their natural environments to determine the degree to which warm conditions increase species co-occurrence and the potential for competitive interactions. (2) A manipulative field experiment will be conducted to measure behavioral responses to thermal stress in crabs caged at two intertidal heights. Temperature variation will be regulated by thickness and composition of artificial stones placed over caged crabs, else conditions will vary naturally. (3) Experimental intertidal zone simulation tanks will be used to test for behavioral and physiological responses of each crab species to thermal stress. Heat lamps will be used to regulate temperatures under stones with differing degrees of immersion. In field (2) and laboratory (3) experiments, crab species will be tested separately and in combination. Physiological condition in all three studies will be assessed from hemolymph (blood) samples using existing gene expression thermal stress biomarkers and yolk protein assays of reproductive activity. Gene expression levels of 44 target transcripts and 6 houskeeping genes will be estimated using the NanoString nCounter platform, a non-amplification based direct measurement of mRNA. Assays of yolk protein (vitellin) from oocytes and yolk protein precursor (vitellogenin) from hemolymph will be performed using antibody-based assays (ELISA) with available antibodies.