A genetic analysis of Drosophila limb patterning

描述（由申请人提供）：拟议工作的目标是获得 深入了解果蝇肢体图案形成的分子机制。 本申请中提出的研究旨在回答以下问题 问题：1）翅膀和腿是如何区分的？分析 LIM-homeobox基因的功能缺失和异位表达表型 DLIM 1提示其参与腿细胞与翅细胞的命运选择。他们还 指出DLIM 1在近端腿域特化中的作用。的功能 dlim 1及其与其他腿和翅膀图案基因的遗传相互作用将 使用镶嵌分析和其他遗传和分子生物学方法进行研究 接近。2)无翅昆虫对假定的背翅是如何调节的？一 背翅无翅增强子已被鉴定。这种增强子是保守的 在小鼠无翅直系同源物（mlhx 2）中。一种候选基因方法， 嵌合体分析、体外DNA结合测定、定点诱变和 将使用转基因分析来鉴定调节子。3)哪些基因 介导来自腹侧隔室的信号，以激活 背腹边界我们假设，基因剪辑参与了 背腹图案化并介导从腹侧到Notch的信号传导 车厢为了检验这一假设，将剪切蛋白产品 它的功能将在细胞培养中和 基因镶嵌来决定它是否能自主发挥细胞功能。 对果蝇肢体模式基因正常功能的理解， 以及确定它们在其中的遗传和信号通路， 参与与公共卫生直接相关。这些基因中有许多是 与人类发育畸形有关， 人类疾病。这些包括不同类型的癌症，中风和痴呆症。

DESCRIPTION (provided by applicant): The goal of the proposed work is to gain insight into the molecular mechanisms of pattern formation in Drosophila limbs. The research proposed in this application is aimed to answer the following questions: 1) How are wings and legs differently specified? Analyses of lack-of-function and ectopic expression phenotypes of the LIM-homeobox gene dlim1 suggest its involvement in leg versus wing cell fate choice. They also point to a role of dlim1 in proximal leg domain specification. The function of dlim1and its genetic interactions with other leg and wing patterning genes will be investigated using mosaic analysis, and other genetic and molecular approaches. 2) How is apterous regulated to the presumptive dorsal wing? A dorsal wing apterous enhancer has been identified. This enhancer is conserved in the mouse apterous orthologue (mlhx2). A candidate gene approach employing mosaic analysis, in vitro DNA binding assays, site directed mutagenesis and transgenic analysis would be used to identify the regulators. 3) What genes mediate signaling from the ventral compartment to activate Notch at the dorso-ventral boundary? We hypothesize that the gene clipped is involved in dorsoventral patterning and mediates signaling to Notch from the ventral compartment. To test this hypothesis the Clipped protein product will be identified, and its function will be investigated in cell culture and in genetic mosaics to determine whether or not it functions cell autonomously. The understanding of the normal functions of Drosophila limb patterning genes, and the identification of the genetic and signaling pathways in which they participate is directly relevant to public health. Many of these genes are implicated in human developmental malformations and in an increasing number of human diseases. These include different types of cancer, stroke and dementia.