The Role of Developmental Genes in Controlling Butterfly Eyespot Patterns

发育基因在控制蝴蝶眼斑模式中的作用

• 批准号: 0316283
• 负责人: Antonia Monteiro
• 金额: $ 24万
• 依托单位: SUNY at Buffalo
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2006-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0316283&HistoricalAwards=false
• 关键词: Role; Developmental; Genes; Controlling; Butterfly

0316283MonteiroThe emerging field of evo-devo seeks to understand the evolutionary processes that have shaped how genotype translates into phenotype, in part by studying variability in genes and the developmental pathways that they control. The colorful and functional patterns on the wings of butterflies provide ideal material for evo-devo research because 1) they are variable both within and across the 12,000 described species, 2) because they represent visually compelling products of selection, often with a known adaptive value, and 3) because the two-dimensional epidermal wing surfaces, where pattern formation takes place, are very amenable to developmental, molecular, and phenotypic characterization. Among the most common pattern elements within the nymphalids are the eyespots: distinct concentric rings of differently colored scales. Eyespots are thought to mimic the appearance of vertebrate eyes, and can either startle an attacking predator or deflect the attack towards the margin of the wing. Recently it was shown that three transcription factors, Spalt, Sal;, Engrailed, En; and Distal-less, Dll, are expressed in the eyespot field of Bicyclus anynana during the pupal wing stage. Sal and Dll are expressed in a central disc of the eyespot, where black scales differentiate, while En is present in a ring of cells around the central disc, correlating to the pattern of gold scales in the adult wing. Additionally, in a mutant line of B. anynana, "Goldeneye," Sal is absent from the central disc of cells, while En is expressed in the whole eyespot field, and the adult pattern consists of an entirely gold eyespot. The experiments outlined in this proposal will test whether there is a causal involvement of Sal and Dll, on the one hand, and En, on the other hand, in differentiating the black and gold colored scales of an eyespot, respectively. The technique of germ line transformation in B. anynana will be developed in order to test whether these genes have been functionally co-opted to specify novel patterns in evolution. Development of a heat-shock promoter system that can activate these transgenes at specific times during development will also be attempted. The function of the candidate genes will be determined by ectopically expressing them in the eyespot field and testing their function and sufficiency in specifying the fate of the colored scales. If, as expected, a causal relationship is established between the transcription factors and differentiation of the colored scales, the ultimate goal will be to dissect the evolution of the regulatory regions of these genes across selected lines within B. anynana, across closely related species with divergent eyespot morphologies, and ultimately across species with and without eyespots in order to understand the relationship between DNA sequence variation and morphological evolution. Merit Criteria I: Much work in evo-devo has been dominated by the characterization of the genetic pathways involved in the development of different species, often times from different phyla. Although comparative studies can, and have, generated fruitful results, studies of variation at the intra-specific level and among closely related species should not be neglected. Indeed, adaptive evolution primarily involves the sorting by natural selection of phenotypic variants present in individuals of the same population, not in individuals of different species. It is important to understand the generation of such intra-specific variation, as well as the possibly more "saltational" mechanisms of gene co-option by comparing the evolution of a set of developmental genes across the Lepidoptera. These aims can be achieved by dissecting the evolution of regulatory genes with a demonstrated key role in differentiating adaptive traits. This project aims to test whether a few candidate genes display that key role. Merit Criteria II: Dr. Monteiro is a new faculty member currently training 2 undergraduate students and two female graduate students, one of which a member of the Native American tribe Choctaw Nation of Oklahoma. This excellent and very promising graduate student has already begun working on the project described here. Dr. Monteiro will continue to train graduate and undergraduates students alike in Population Genetics, Phylogenetics, and Developmental Biology, irrespective of gender and ethnicity, in order to provide them with a broad multifaceted approach to Evolution and Development. In addition, this project has a cross-disciplinary component where graduate students will be working with members of the Physics department and taking appropriate graduate courses in that Department as well.

0316283蒙泰罗进化-发育的新兴领域试图理解形成基因型如何转化为表型的进化过程，部分通过研究基因的变异性和它们控制的发育途径。蝴蝶翅膀上的色彩缤纷和功能性图案为进化发育研究提供了理想的材料，因为1）它们在12，000个描述的物种内和之间都是可变的，2）因为它们代表了视觉上引人注目的选择产品，通常具有已知的适应价值，3）因为二维表皮翅膀表面，图案形成的地方，非常适合发育，分子和表型表征。若虫最常见的图案元素之一是眼斑：不同颜色鳞片的明显同心环。眼点被认为是模仿脊椎动物眼睛的外观，可以惊吓攻击的捕食者，也可以将攻击转移到翅膀的边缘。最近的研究表明，三个转录因子Spalt，Sal;，Engrailed，En;和Distal-less，Dll，在蛹翅期在Bicyclus anynana的眼斑区表达。Sal和Dll在眼斑的中央圆盘中表达，其中黑色鳞片分化，而En存在于中央圆盘周围的细胞环中，与成虫翅膀中的金色鳞片图案相关。此外，在B. Anynana，“Goldeneye”，Sal在中央细胞盘中不存在，而En在整个眼斑区域中表达，并且成体图案由完全金色的眼斑组成。本提案中概述的实验将测试Sal和Dll以及En是否分别在区分眼点的黑色和金色刻度中存在因果关系。介绍了B. anynana将被开发，以测试这些基因是否在功能上被增选以指定进化中的新模式。还将尝试开发一种可以在发育过程中的特定时间激活这些转基因的热休克启动子系统。候选基因的功能将通过在眼点区域异位表达它们并测试它们在指定有色鳞片命运中的功能和充分性来确定。如果像预期的那样，在转录因子和有色鳞片的分化之间建立了因果关系，最终的目标将是在B内的选定品系中剖析这些基因的调控区的进化。anynana，在密切相关的物种与不同的眼点形态，并最终在物种与无眼点，以了解DNA序列变异和形态进化之间的关系。优点标准I：进化-发育的许多工作一直被描述不同物种（通常来自不同的门）发育中的遗传途径所主导。虽然比较研究可以而且已经产生了丰硕的成果，但不应忽视种内水平和密切相关物种之间的变异研究。事实上，适应性进化主要涉及通过自然选择对同一种群个体中存在的表型变异进行分类，而不是不同物种的个体。重要的是要了解这种种内变异的产生，以及可能更多的“跳跃”机制的基因co-option通过比较整个鳞翅目的一组发育基因的进化。这些目标可以通过解剖调控基因的进化来实现，这些调控基因在区分适应性性状方面具有关键作用。该项目旨在测试一些候选基因是否显示出这种关键作用。优点标准II：蒙泰罗博士是一名新教师，目前正在培训2名本科生和2名女研究生，其中一名是俄克拉荷马州美洲土著部落乔托族的成员。这位优秀的、非常有前途的研究生已经开始从事这里描述的项目。蒙泰罗博士将继续培养研究生和本科生在人口遗传学，系统发生学和发育生物学，无论性别和种族，以提供他们一个广泛的多方面的方法来进化和发展。此外，该项目有一个跨学科的组成部分，研究生将与物理系的成员一起工作，并在该部门参加适当的研究生课程。