Developmental Genetics and Evolution of Butterfly Colour Patterns

物种是生物学的基本单位，但与化学和物理中类似的单位不同，使物种彼此不同的确切性质并不完全清楚。进化发育生物学的目标是了解导致物种间表型差异的遗传变异和发育机制。这项拟议的研究使用七叶树蝴蝶(Junonia属，前身为Precis)作为研究物种差异的进化遗传和发展基础的模型。北美常见七叶树蝶(J.coenia)的颜色模式发育已被广泛研究。 该属原产于非洲，据认为仅有4种朱尼亚属植物分布于新大陆。自2009年以来，系统发育研究(其中大部分来自我的实验室)澄清了分类学，并确定了隐秘的朱诺亚目物种。现在有10种已描述的新大陆朱尼亚属物种，还有一些尚未描述(特别是在南美洲)。新世界朱诺尼亚物种在颜色模式、身体大小、物候、飞行行为和地理范围上都不同。许多物种专攻不同的幼虫寄主植物，促进物种在同一栖息地长期共存。然而，大多数朱诺尼亚物种在圈养条件下很容易杂交，所有物种都可以在相同的实验室食物中饲养。我的实验室已经证明，朱诺尼亚物种之间的杂交和基因流动在自然界中也会发生。 这些属性再加上牛膝中已有的各种工具和资源(许多克隆的基因和快速增长的基因组资源、荷尔蒙操作、发育扰动、基因表达和转基因的方法)，使该属成为了解物种形成和物种差异的进化和发展的极好系统。该研究计划侧重于朱诺尼亚物种之间的形态差异：特别是，我们的目标是识别进化模式以及身体大小和颜色模式变化的遗传和发育基础。身体大小强烈影响蝴蝶与其生物和非生物环境的相互作用，而眼点在抵抗捕食者防御方面具有重要作用。因此，我们将研究具有重要生态意义的形态性状的遗传和发育基础。这种科学方法使用一种新的研究方法组合来调查朱诺属物种之间的多样化、杂交模式和形态差异的发育遗传学基础。 意义和更广泛的影响：这项研究将在尖端实验技术方面培训高素质的人员，以确定导致物种在具有生态重要性的表型特征方面相互不同的基因、发育过程和进化机制。

Species are the fundamental units of biology, but unlike similar units in chemistry and physics, the exact properties that make species different from one another are not fully understood. The goal of evolutionary developmental biology is to understand genetic variation and developmental mechanisms responsible for phenotypic differences between species. The proposed research uses buckeye butterflies (genus Junonia, formerly Precis) as a model for studying the evolutionary genetic and developmental basis for species differences. Colour pattern development in the North American common buckeye butterfly, J. coenia, has been studied extensively. The genus originated in Africa and it was thought that only 4 Junonia species occurred in the New World. Since 2009, phylogenetic work (much of it from my laboratory) has clarified taxonomy and identified cryptic Junonia species. There are now 10 described New World Junonia species, with others that are yet undescribed (especially in South America). New World Junonia species differ in colour pattern, body size, phenology, flight behaviour, and geographic range. Many species specialize on distinct larval host plants, facilitating the long-term co-occurrence of species in the same habitat. Yet, most Junonia species hybridize readily in captivity and all species can be reared on the same laboratory diet. My laboratory has shown that hybridization and gene flow between Junonia species also occurs in nature. These attributes combined with the diverse tools and resources already available in J. coenia (many cloned genes and rapidly increasing genomic resources, methods for hormonal manipulation, developmental perturbation, gene expression, and transgenesis) make this genus an excellent system for understanding speciation and the evolution and development of species differences. The research program focuses on the morphological differences between Junonia species: in particular, our objectives are to identify patterns of evolution and the genetic and developmental basis for variation in body size and colour pattern. Body size strongly influences how butterflies interact with their biotic and abiotic environment, while eyespots have an important role in anti-predator defense. Thus, we will be studying the genetic and developmental basis of ecologically important morphological traits. The scientific approach uses a novel combination of research methodologies to investigate patterns of diversification, hybridization, and the developmental genetic basis for differences in morphology among Junonia species. Significance and broader impacts: This research will train highly qualified personnel in cutting-edge experimental techniques to identify the genes, developmental processes, and evolutionary mechanisms responsible for making species different from one other with respect to phenotypic traits of ecological importance.