The Role of Developmental Genes in Controlling Butterfly Eyespot Patterns II

发育基因在控制蝴蝶眼斑模式中的作用 II

• 批准号: 0516705
• 负责人: Antonia Monteiro
• 金额: --
• 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: 2005
• 资助国家: 美国
• 起止时间: 2005-11-01 至 2006-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0516705&HistoricalAwards=false
• 关键词: Role; Developmental; Genes; Controlling; Butterfly

The emerging field of evo-devo studies, in part, how genotype connects to phenotype. This project seeks to test the function of a few candidate transcription factors in the development of butterfly eyespots. Several transcription factors and gene circuits that are known to be involved in wing and leg development in Drosophila are hypothesized to be involved in the development of eyespots in butterflies. In particular, when Distal-less (Dll) is ectopically activated in Drosophila it causes complete leg duplications, thus suggesting a master regulatory function. In Bicyclus, Dll is expressed in signaling cells in the eyespot's center at the earliest stages of eyespot development, and moreover, variation in Dll is linked with variation in eyespot size. Have butterflies co-opted the same "leg" developmental circuit in the formation of eyespots? An activated ligand receptor, phosphorylated Mothers Against Decapentaplegic, pMad, is expressed in the eyespot field during early pupal development. Is the morphogen Decapentaplegic (Dpp) being produced at the eyespot's center, diffusing to surrounding cells and differentiating a complete eyespot pattern? Another transcription factor, Engrailed (En), is expressed in a ring of epidermal cells that correlates with the pattern of gold colored scales on the eyespot of the adult Bicyclus wing. Does En cause the differentiation of gold colored scales in eyespots? The experiments outlined in this project test these hypotheses by ectopically expressing Dll, Dpp, and En on the developing wing and observing whether, in the first two cases, a complete eyespot pattern differentiates around the site of expression, or whether, in the second case, gold scales develop at the site of expression. Additional experiments will test whether over-expressing Dll and Dpp at the eyespot's center will lead to differences in eyespot size. To induce ectopic expression the lab has developed a laser-assisted heat-shocking technique that will allow the activation of these genes in a controlled spatial and temporal fashion on the developing wing of transgenic butterflies. The heat-shocking technique has been successfully tested with a fluorescent marker gene but now this marker will be substituted for the coding sequences of Dll, Dpp, and En. Establishing a causal relationship between these genes and differentiation of eyespots or colored scales will allow the later examination of the relationship between the evolution of these genes and the evolution of the phenotype. Intellectual merit: Much work in evo-devo has been dominated by inferring novel functions for genes based solely on their novel expression domains. This project intends to go beyond the correlational evidence and to really test whether "old" developmental genes belonging to known gene circuits have been functionally co-opted to specify a morphological novelty in evolution, butterfly eyespots. Once this functional co-option is established future work will attempt to track the evolution of eyespots, from their creation throughout their various levels of quantitative and qualitative modifications. This long-term study will dissect the evolution of regulatory genes with a demonstrated key role in differentiating these adaptive traits. This project aims to test whether a few candidate genes display that key role. In addition, this project will make available a series of transformation constructs of wide applicability across organisms, as well as develop important tools for functional genetics in non-model organisms. Broader Impacts: Dr. Monteiro has currently involved one postdoc and 3 graduate students in this project. One is a woman and a member of the Native American tribe Choctaw Nation of Oklahoma. Another is a minority graduate student in the Department of Electrical Engeneering at Buffalo. These two students are both recipients of NSF IGERT training grants in Biophotonics, and are truly working at the interface of Biology and Photonics via an established collaboration with the Department of Electrical Engineering at Buffalo. She 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.

EVO-DEVO这一新兴领域部分研究了基因与表型之间的联系。这个项目试图测试几个候选转录因子在蝴蝶眼点发育过程中的功能。一些已知参与果蝇翅膀和腿发育的转录因子和基因回路被假设参与蝴蝶眼点的发育。特别是，当远端无末端(DLL)在果蝇中被异位激活时，它会导致完全的腿部复制，因此暗示了一种主要的调节功能。在双眼蜂中，Dll在眼点发育的最早阶段在眼点中心的信号细胞中表达，而且Dll的变化与眼点大小的变化有关。在形成眼点的过程中，蝴蝶是否也选择了同样的“腿”发育回路？一种激活的配体受体pMad在幼虫发育早期的眼点区表达。是不是在眼点中心产生的形成性十足麻木(DPP)扩散到周围的细胞，并分化成一个完整的眼点图案？另一种转录因子Engrailed(EN)在一环表皮细胞中表达，该环状表皮细胞与成虫眼斑上金色鳞片的图案相关。是不是EN导致了眼点上金色鳞片的分化？本项目中概述的实验通过在发育中的翅膀上异地表达Dll、DPP和EN并观察在前两种情况下，表达部位周围是否有完整的眼点图案，或者在第二种情况下，表达部位是否形成金色鳞片来检验这些假说。其他实验将测试在眼点中心过度表达DLL和DPP是否会导致眼点大小的差异。为了诱导异位表达，该实验室开发了一种激光辅助热休克技术，将允许在转基因蝴蝶发育的翅膀上以受控的空间和时间方式激活这些基因。热休克技术已经成功地用一个荧光标记基因进行了测试，但现在这个标记将取代Dll、DPP和EN的编码序列。建立这些基因和眼斑或有色鳞片的分化之间的因果关系，将允许稍后检查这些基因的进化和表型进化之间的关系。智力优势：EVO-DEVO的许多工作主要是仅根据基因的新表达结构域来推断基因的新功能。这个项目的目的是超越相关证据，真正测试属于已知基因电路的“旧”发育基因是否在功能上被增选，以确定进化中的一种形态上的新奇事物--蝴蝶眼点。一旦这种功能选择建立起来，未来的工作将试图跟踪眼点的演变，从它们的创建到它们不同程度的数量和质量修改。这项长期研究将剖析调控基因的进化，并证明其在区分这些适应性特征方面的关键作用。这个项目的目的是测试几个候选基因是否显示出这种关键作用。此外，该项目将提供一系列广泛适用于生物的转化结构，以及开发用于非模式生物的功能遗传学的重要工具。更广泛的影响：蒙泰罗博士目前在这个项目中有一名博士后和三名研究生。其中一人是一名妇女，是俄克拉何马州乔克托部落的印第安人。另一位是布法罗大学电气工程系的一名少数民族研究生。这两名学生都是NSF IGERT生物光子学培训助学金的获得者，通过与布法罗电气工程系建立的合作关系，他们真正致力于生物与光子学的接口工作。她将继续对研究生和本科生进行人口遗传学、系统遗传学和发育生物学方面的培训，不分性别和种族，以便为他们提供广泛的、多方面的进化和发展方法。