Impact of environmental change on the physiological and adaptive responses of aquatic organisms

由于人类活动和全球变暖，动物必须科普的环境压力的范围和可变性不断增加。了解动物对这种不同环境的反应是揭示驱动复杂生物过程的潜在力量的第一步，例如生物体的适应和微进化。由J. Elser及其同事开发的一种广泛通用的方法试图将细胞分配与生物体功能和生态动力学联系起来。简单地说，快速生长的生物体被认为具有低生物量C：P和N：P比率，这反映了对快速蛋白质合成所需的富含P的核糖体RNA（rRNA）的分配增加，以支持快速生长。高生长速率表型的遗传机制涉及核糖体RNA基因的结构和组织，特别是基因间间隔区（IGS）长度的异质性。这意味着，进化过程中可以产生变化的主要生活史性状（特定的生长速率），并有生态动态的后果，由于其对有机体元素组成的影响。我的研究计划的总体目标是：1）了解不断变化的环境条件如何影响生理反应，主要是水生生物的生长速度; 2）通过识别和调查与生长有关的功能相关的遗传变异来了解水生生物的适应性反应。 作为一个模型系统，我将主要集中在圣皮埃尔湖（LSP），在圣劳伦斯河系统的三个河流湖泊中最大的，由于高度复杂的水文呈现重要的空间和时间的环境变化。我将着手解决之间的联系，生长速度，有机体C：N：P和IGS长度变化的黄鲈（Perca flavescens）在不同的营养供应条件下。使用从分子生物学到生态学的综合化学计量方法，我的研究计划将解决一般进化生物学中根本性的重要问题，这些问题使用传统方法是不可能实现的。

As a consequence of human activity and global warming, the range and variability of environmental pressures that animals must cope with is constantly increasing. Understanding animal response to such varying environments is a first step towards uncovering the underlying forces driving complex biological processes, such as adaptation and microevolution of organisms. A broadly generalized approach, developed by J. Elser and colleagues attempts to link cellular allocation to organism function and to ecological dynamics. Briefly, rapidly growing organisms are thought to have low biomass C:P and N:P ratios that reflect an increased allocation to P-rich ribosomal RNA (rRNA) needed for rapid protein synthesis to support fast growth. Genetic mechanisms underlying high growth rate phenotypes implicate the structure and organisation of ribosomal RNA genes, notably heterogeneity in intergenic spacer (IGS) length. This implies that evolutionary processes can generate variation in a major life history trait (specific growth rate) and have consequences for ecological dynamics due to their effects on organismal elemental composition. The general objectives of my research program are: 1) to understand how changing environmental conditions impact physiological responses, mainly the growth rates of aquatic organisms; 2) to understand the adaptive responses of aquatic organisms by identifying and investigating functionally relevant genetic variation implicated in growth. As a model system I will focus mainly on Lake Saint-Pierre (LSP), the largest of the three fluvial lakes in the St. Lawrence River system, presenting important spatial and temporal environmental variations due to a highly complex hydrology. I will proceed to address the connections between growth rate, organism C:N:P and IGS length variation in yellow perch (Perca flavescens) under different conditions of nutrient supply. Using an integrated stoichiometric approach from molecular biology to ecology, my research program will address fundamentally important questions in evolutionary biology in general that have not been otherwise possible using conventional approaches.