Collaborative Research: Nutritional physiology of life history allocation trade-offs

生活史特征，如寿命，传播和总繁殖输出是关键的生物适应。 许多生活史性状彼此负耦合，因为分配给一个性状（例如产蛋量）的营养素不能用于另一个性状（例如用于传播的脂质燃料的生产）。 权衡的幅度可以强烈影响的数量和质量的营养物质提供给一个有机体，但目前很少有人知道营养投入如何影响生活史的权衡。 在这里，这个问题进行了调查，使用翼多态蟋蟀，蟋蟀firmus。 这种蟋蟀是两种遗传上特定的形式之一，一种适应于以产卵为代价的飞行（传播），另一种适应于以传播为代价的最大化繁殖（它缺乏飞行肌肉）。 使用一系列定义明确的饮食，不同的蛋白质-碳水化合物组成（和总卡路里含量），将进行比较，揭示这两种对比的表型如何差异提取，相互转换，并消除其特定的生活史所需的蛋白质和碳水化合物。 具体而言，本研究将测量蛋白质和碳水化合物的消耗和同化到身体组织中，记录这两种营养素如何分配到飞行和生殖器官，并使用放射性示踪剂和生化途径的酶学研究来研究这两种营养素的相互转化和代谢消除。 一个重要的重点将是确定允许特定表型在不断变化的营养环境中获得/产生其所需的生物分子（用于其生命史）的生理机制。 结果将适用于广泛的生物体，包括人类的生活史特征（如寿命）。 该项目也有一个重要的教学组成部分，包括博士后助理的培训，本科生的研究机会，并为中学教育工作者提供新的方法来教授进化论的基本原则研讨会的发展。

Life history traits such as longevity, dispersal and total reproductive output are key organismal adaptations. Many life history traits are negatively coupled with each other because nutrients allocated towards one trait (e.g. egg production) are not available for another trait (e.g. production of lipid fuel for dispersal). The magnitude of trade-offs can be strongly influenced by the amount and quality of nutrients available to an organism, but currently little is known about how nutrient inputs affect life history trade-offs. Here this issue is investigated using a wing-polymorphic cricket, Gryllus firmus. This cricket exists as one of two genetically-specified forms, one adapted for flight (dispersal) at the expense of egg production, the other adapted to maximize reproduction at the expense of dispersal (it lacks flight muscle). Using a range of well-defined diets that differ in their protein-carbohydrate composition (and total caloric content), a comparison will be made that reveals how these two contrasting phenotypes differentially extract, interconvert, and eliminate protein and carbohydrate demanded by their specific life history. Specifically, this study will measure consumption and assimilation of protein and carbohydrates into body tissues, document how these two nutrients are allocated to flight and reproduction organs, and use radiotracer and enzymological studies of biochemical pathways to study interconversion and metabolic elimination of these two nutrients. An important focus will be identifying the physiological mechanisms that allow a particular phenotype to acquire/produce the biomolecules it needs (for its life history) in a constantly shifting nutritional environment. Results will be applicable to a wide range of organisms, including life history traits (e.g. longevity) in humans. This project also has a significant instructional component, including the training of a postdoctoral associate, research opportunities for undergraduate students, and the development of workshops for secondary school educators which provides novel approaches to teaching basic principles of evolution.