A genetic analysis of Drosophila limb patterning

描述(由申请人提供)：建议工作的目标是获得 洞察果蝇四肢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)翅膀和腿是如何不同地指定的？分析了 LIM-Homeobox基因功能缺失和异位表达表型 Dlim1提示它参与了腿细胞对翅膀细胞的命运选择。他们也 指出dlim1在腿部近端区域规范中的作用。的功能 Dlim1及其与其他腿部和翅膀图案基因的遗传交互作用将 利用镶嵌分析和其他遗传和分子研究 接近了。2)非翅目动物对假定的背翼是如何调节的？一个 背翼无翅增强子已被鉴定。这种增强剂是保守的 在小鼠无翅直系同源基因(Mlhx2)中。一种候选基因方法 镶嵌分析，体外DNA结合分析，定点突变和 转基因分析将被用来识别监管机构。3)哪些基因 调节来自腹侧隔室的信号以激活 背腹分界？我们假设被剪断的基因参与了 背腹侧模式及其介导腹侧切迹的信号传导 车厢。为了验证这一假设，剪裁的蛋白质产品将是 它的功能将在细胞培养中和在 基因嵌合体，以确定它是否自主地发挥细胞功能。 了解果蝇肢体模式基因的正常功能， 以及它们所处的遗传和信号通路的鉴定 参与与公众健康直接相关。这些基因中有许多是 与人类发育畸形有关，并与越来越多的 人类疾病。这些疾病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.