Pattern Formation and Eyespot Determination in Butterfly Wings

蝴蝶翅膀上的彩色图案是细胞场中图案形成的最壮观的例子。 然而，人们对这些模式如何发展和演变知之甚少。 最近，通过克隆许多果蝇附肢模式基因的蝴蝶同源物，开始了对蝴蝶翅膀模式形成的分子表征。 这些基因在发育中的成虫盘中的表达表明，虽然发育中的蝴蝶翅膀的整体组织与果蝇的相似，但蝴蝶翅膀的亚组织以调控基因表达的新的动态模式为标志，其中一些预示着成年翅膀模式元件的未来位置。 本文提出的项目旨在验证三个假设，这些假设来自于蝴蝶翅膀图案景观的初步特征，包括：（1）眼斑的形成是一个涉及近中端图案基因的遗传电路的产物;（2）分泌的无翅蛋白、十肢麻痹蛋白和刺猬信号蛋白参与了翅膀图案的形成;（3）发育前模式可能是保守的，下游基因对发育前模式的解释具有种特异性。 实验计划包括克隆几个额外的proximodistal图案基因，分析其空间和时间的关系，在整个翅膀形成，个别蛋白质的功能，通过异位表达研究评估，并在不同的蝴蝶物种的发育prepatterns的比较分析。 描述性的，实验性的和比较性的工作相结合的目的是确定一些主要的机制，指导发展和进化的翅膀模式。

The color patterns of butterfly wings are some of the most spectacular examples of pattern formation in cellular fields. Little is known, however, about how these patterns develop and evolve. Recently, a molecular characterization of butterfly wing pattern formation was initiated by cloning butterfly homologs of numerous Drosophila appendage- patterning genes. The expression of these genes in developing imaginal discs indicates that while the overall organization of the developing butterfly wing is similar to that of Drosophila, the suborganization of the butterfly wing is marked by novel and dynamic patterns of regulatory gene expression, some of which presage the future position of adult wing pattern elements. The project proposed here aims to test three hypotheses emanating from this initial characterization of the patterning landscape in butterfly wings, including: (1) eyespot formation is the product of a genetic circuit involving proximodistal patterning genes; (2) the secreted wingless, decapentaplegic and hedgehog signaling proteins are involved in wing pattern formation; and (3) the developmental prepattern may be conserved and its interpretation by downstream genes is species-specific. The experimental plan involves the cloning of several additional proximodistal patterning genes, the analysis of their spatial and temporal relationships throughout wing formation, assessment of individual protein functions through ectopic expression studies, and the comparative analysis of developmental prepatterns in different butterfly species. The combination of descriptive, experimental, and comparative work is aimed at identifying some of the principal mechanisms guiding the development and evolution of wing patterns.