An integrated approach to stress in fish: behaviour, molecular biology and physiology

我的研究项目的长期目标集中在整合鱼类的生理和行为，以及理解鱼类的气体转运和酸碱调节策略。虽然这两个目标表面上看起来截然不同，但实际上它们是由诸如应激反应、皮质醇、酸碱和离子调节、碳水解酶(CA)和二氧化碳排泄等统一主题联系在一起的。尽管从整合生理和行为的角度来看，我们使用虹鱼的社会等级来研究社会地位的生理原因和后果。在其中，我们关注了低社会地位的直接生理成本，包括生长抑制、对低O2的耐受性降低以及慢性社会压力对急性应激反应的影响，现在我建议识别社会诱导的生长抑制背后的生理机制，并调查低社会地位对离子调节和酸碱平衡的影响。这项工作的目的是提高我们对支撑行为的生理机制的理解，但获得的信息在应用环境中也可能是重要的，例如预测污染物对鱼类种群的影响，或设计有效的水产养殖实践。关于了解鱼类气体转运和酸碱调节策略的长期目标，我的目标是在我们最近鉴定鱼类CA分子结构和功能的基础上再接再厉。CA是一种几乎普遍存在的酶，它催化二氧化碳反应，因此有助于从二氧化碳排泄、酸碱平衡到新陈代谢等生理过程。我建议探索我们从肺鱼克隆的一组CA亚型的生理作用，以研究CA在酸碱失衡过程中的表达调节。通过产生有关鱼类CA亚型及其功能的新信息，这项工作将增加我们对鱼类气体转运和酸碱调节以及脊椎动物CA基因家族进化的理解。

The long-term objectives of my research program focus on integrating physiology and behaviour in fish, and on understanding piscine strategies for gas transfer and acid-base regulation.  While these two objectives appear superficially to be quite disparate, they are in fact linked by such unifying themes as stress responses, cortisol, acid-base and ionic regulation, the enzyme carbonic anhydrase (CA), and CO2 excretion.      In terms of integrating physiology and behaviour, we use social hierarchies in rainbow trout to examine the physiological causes and consequences of social status.  Building on recent progress in this area, in which we have focused on the immediate physiological costs of low social status, including growth depression, reduced tolerance of low O2 and the impact of chronic social stress on acute stress responses, I now propose to identify the physiological mechanisms underlying socially-induced growth depression and investigate the impact of low social status on ionic regulation and acid-base balance.  The aim of this work is to improve our understanding of the physiological mechanisms underpinning behaviour, but the information gained can also be important in an applied setting, for example in predicting the impact of pollutants on fish populations, or in designing effective animal husbandry practices for aquaculture.    With respect to the long-term goal of understanding strategies for gas transfer and acid-base regulation in fish, I aim to build on our recent progress in identifying the molecular structure and function of fish CAs.  CA is a near-ubiquitous enzyme that catalyzes CO2 reactions and hence contributes to physiological processes ranging from CO2 excretion and acid-base balance to metabolism.  I propose to explore the physiological roles of a group of CA isoforms that we cloned from lungfish, to examine the regulation of CA expression during acid-base disturbances, and to identify hypoxia-inducible CA isoforms in zebrafish.  By generating new information on CA isoforms in fish and their functions, this work will increase our understanding both of gas transfer and acid-base regulation in fish, and of the evolution of the CA gene family in vertebrates.