Molecular Mechanisms and Evolution of Phenotypic Plasticity

从植物到人类，各种生物都在利用表型可塑性。它的无处不在证明了 到它在生活中的根本重要性。这个项目解决了一个引人入胜而又未被充分研究的问题 表型可塑性的机制基础--即发育过程如何受 导致表型差异的环境线索--以及重要的是，这些过程是如何演变的。这个 这里的焦点是一种创新的模式，豌豆蚜虫，它展示了一个典型的表型 可塑性。这个物种提供了一个无与伦比的机会来研究先天和后天在 表型鉴定：它表现出明显不同的有翼和无翼的形态，由 环境条件在遗传上相同的、无性的雌性中，并受一个基因座控制。 男性。因此，引人注目的是，在这个单一的个体中存在着两种二态，每一种都在不同的控制机制下 物种。拟议中的实验建立在PI最近关于P4的作用的令人兴奋的发现的基础上 激素和水平转移基因在雌翅可塑性中的作用及其鉴定 男性的翅膀多态基因座，其插入包含一个重复的基因，该基因影响 信号(卵泡抑素)，这是专门针对无翼雄性。拟议的、充满活力的研究计划旨在 破译可塑性功能和进化的分子机制。在此基础上进行的实验 机翼可塑性将研究控制它的调控变化，以及伴随它的表观遗传变化， 并测试水平转移的基因是否优先招募到这一过程中。在此基础上进行的实验 遗传性雄性翅膀二型性将利用卵泡抑素类似物的功能和进化研究来建立 这些对虾的变化如何成为雄性形态进化的基础。对女性和男性的研究将是 与实验相结合，这些实验将测试最近衍生的男性二型性是否由 女性可塑性的遗传适应，假设男性绕过环境信号 被女性所用的可塑性。这些研究将提供一些初步的洞察力，以了解 遗传适应，即性状变异从“后天”转变为“先天”。这些 实验将对理解塑性的机制基础和演化具有广泛的意义， 从人类健康的角度来看，这一点意义重大，因为许多塑料特征会影响 人类的健康和疾病。

Phenotypic plasticity is used by an incredible diversity of organisms, from plants to humans. Its ubiquity attests to its fundamental importance in life. This project addresses the fascinating and understudied question of the mechanistic basis of phenotypic plasticity – i.e., how developmental processes are influenced by environmental cues to cause phenotypic differences -- and, importantly, how those processes evolve. The focus here is on an innovative model, the pea aphid, which exhibits a textbook example of phenotypic plasticity. This species offers an unparalleled opportunity to examine the role of nature and nurture in phenotype determination: it exhibits dramatically different winged and wingless morphs that are induced by environmental conditions in genetically identical, asexual females and controlled by a single genetic locus in males. Thus, strikingly, two dimorphisms, each under different control mechanisms, exist within this single species. The proposed experiments build on the exciting recent discoveries made by the PI about the role of hormones and horizontally transferred genes in the female wing plasticity and about the identification of the wing polymorphism locus in males, which has an insertion containing a duplication of a gene that influences signaling (follistatin) and which is specific to wingless males. The proposed, vigorous research program aims to decipher the molecular mechanisms underlying the function and evolution of plasticity. Experiments on the wing plasticity will examine the regulatory changes that control it, the epigenetic changes that accompany it, and test if horizontally transferred genes are preferentially recruited into the process. Experiments on the genetic male wing dimorphism will use functional and evolutionary studies of the follistatin paralogs to establish how changes in these paralogs underlie male morphological evolution. Studies in females and males will be united with experiments that will test whether or not the more recently derived male dimorphism evolved by genetic accommodation of the female plasticity, hypothesizing that males bypass the environmental signals used by the female plasticity. These studies will provide some of the first insights into the mechanistic basis of genetic accommodation, where trait variation shifts from being caused by “nurture” to “nature”. These experiments will have broad implications for understanding the mechanistic basis and evolution of plasticity, which is significant from a human health perspective because of the numerous plastic traits that influence human health and disease.