The Role of Development in Reaction Norm Evolution

“反应标准”描述了当环境改变时，一个特征如何变化，例如，由于昆虫、哺乳动物和其他生物体的早期营养变化，成人的体型如何变化。这种变异通常是深刻的，在许多情况下，变异表现出额外的特征，这些特征是对特定环境的适应。反应规范有一个遗传基础，不同基因组的生物体通过反应规范适应环境的能力不同。由于个体之间的这种遗传差异，通过选择来改变反应标准是可能的，从而改变并可能改善有机体对可变环境的适应。这项拟议的工作将通过研究两种具有不同生长特征的鳞翅目昆虫的体型与营养相关的反应标准的遗传学来检验这一假设。这项工作将首次研究决定体型的潜在发育生理学的遗传学。这种生理学由激素分泌模式组成，这些激素分泌模式控制着动物开始向成年变态的时间。由于PI早期对这个系统的发育生理学的研究，这个系统对生长和成熟的发育控制比几乎任何其他生物体都更好地理解。这使我们能够启动拟议的研究，即基因变异如何影响控制最终成年身体大小的发育过程的变异。这项工作将加深我们对导致体型变化的反应规范是如何受到遗传和发育调控的理解。

A "reaction norm" is a description of how a trait changes when the environment changes, for instance, how adult body size varies due to variation early nutrition in insects, mammals, and other organisms. Such variation is often profound and in many cases the variants exhibit additional traits that are adaptations to a particular environment. Reaction norms have a genetic basis, and organisms with different genomes differ in their ability to adapt to their environment via a reaction norm. Because of such genetic differences among individuals, it should be possible to change the reaction norm by selection and therefore change and perhaps improve the adaptation of organisms to a variable environment. The proposed work will test this hypothesis by studying the genetics of the reaction norm of body size in relation to nutrition in two species of Lepidoptera with different growth characteristics. This work will, for the first time, study the genetics of the underlying developmental physiology that determines body size. This physiology consists of patterns of hormone secretion that control when the animal begins metamorphosis to the adult. Because of the PI's earlier work on the developmental physiology of this system, the developmental control of growth and maturation are better understood in this system than in almost any other organism. This enables us to initiate the proposed investigation of how genetic variation affects variation of the developmental processes that control the final adult body size. This work will enhance our understanding of how the reaction norms that lead to variation in body size are regulated by genetics and development.