International Research Fellowship Program: Nutritional Ecology and the Evolution of Seasonal Color Polymorphism in a Butterfly

国际研究奖学金计划使美国科学家和工程师能够在国外进行9到24个月的研究。该项目的奖项提供了联合研究的机会，并利用国外独特或互补的设施、专业知识和实验条件。该奖项将支持内森·I·莫尔豪斯博士与法国图尔斯大学的杰罗姆·卡萨斯博士合作的为期24个月的研究奖学金。大型色彩装饰品是自然界中最引人注目的特征之一，但其生产和进化的许多方面仍鲜为人知。例如，除了少数几个动物物种外，我们对生产彩色图案的成本和生理权衡的理解仍然不完整。无脊椎动物的颜色尤其如此，它们代表了动物界中一些最显眼的颜色成员。PI正在使用欧洲地图蝴蝶Araschnia Levana的进化框架来更好地了解着色的成本，Araschnia Levana是一种蝴蝶物种，以其两种季节性颜色变形而闻名，即明亮的橙色春季变形和黑白夏季变形。虽然这两种颜色在视觉上是截然不同的，但它们的颜色模式在生物化学上可能更不同。春季的翅膀图案需要合成和沉积大量的橙色全色素，而夏季的翅膀图案需要使用大量的黑色素来产生翅膀图案。这两种色素需要不同的基本营养素来合成：全色素需要氨基酸色氨酸，而黑色素是由酪氨酸和/或苯丙氨酸合成的。这种基本的生化差异很可能会对每种颜色变体的产生的生理机制和权衡产生强烈的影响。他正在研究支持A.Levana？S两种颜色变型发育的营养动态，试图量化1)可用资源的季节性变化，2)营养吸收的季节性差异，3)营养分配和由此产生的生活史权衡的不同，以及4)蜕皮激素和/或保幼激素在调节生长组织之间对涉及颜色产生的资源的竞争中的作用。他的研究结果将使我们更好地了解这种颜色多态的进化，也许还有更广泛的颜色特征。

0754487MorehouseThe International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a twenty-four month research fellowship by Dr. Nathan I. Morehouse to work with Dr. Jerome Casas at the University of Tours in France.Large color ornaments are some of the most eye-catching traits in the natural world, and yet many aspects of their production and evolution remain poorly understood. For example, in all but a select few animal species, our understanding of the costs and physiological tradeoffs associated with producing color patterns is still incomplete. This is particularly true for coloration in invertebrates, which represent some of the most conspicuously colored members of the animal kingdom. The PI is working to better understand the costs of coloration within an evolutionary framework using the European Map Butterfly, Araschnia levana, a butterfly species known for its two seasonal color morphs, a bright orange spring morph and a black-and-white summer morph. While these two color morphs are distinct visually, their color patterns are perhaps even more different biochemically. The wing patterns of the spring morph require the synthesis and deposition of large amounts of orange ommochrome pigments, whereas the summer morph uses large amounts of melanin pigments to produce its wing patterns. These two pigment types draw on different pools of basic nutrients for their synthesis: ommochromes require the amino acid tryptophan, whereas melanin is synthesized from tyrosine and/or phenylalanine. Such basic biochemical differences are likely to have a strong influence on the physiological mechanisms and tradeoffs associated with the production of each color morph. He is investigating the nutrient dynamics that underlie the development of A. levana?s two color morphs, seeking to quantify 1) seasonal variation in available resources, 2) seasonal differences in nutrient uptake, 3) differences between seasonal morphs in nutrient allocation and resulting life-history tradeoffs, and 4) the role of ecdysone and/or juvenile hormone in mediating competition between growing tissues for resources involved in color production. Results from his work will allow us to better understand the evolution of this color polymorphism, and perhaps color traits more generally.