Genome-wide analysis of gene expression in imaginal discs Drosophila melanogaster

基因表达的调控是发育动物细胞命运和组织分化的关键。因此，确定生物体内所有基因的表达模式将是理解其发展背后的调控网络的基础。我们中的一个人（PT）最近生成了大量RNA探针，通过RNA原位杂交确定了黑腹果蝇胚胎中7590个（总共约14000个）基因的表达模式。这一分析揭示了反映胚胎细胞复杂性的多种表达模式。在这里，我们建议使用我们收集的大量RNA探针来全面确定幼虫影像椎间盘中的基因表达模式，简单上皮经常被用作研究发育机制的模型组织。我们的目标有两个：首先，广泛的目标是提供一个在上皮组织中进行模式决定的基因表达调控的公正概述，并解读其发展背后的调控网络。其次，我们更具体的目标是基于它们的表达模式来识别新的Hedgehog信号转导途径的靶基因。Hedgehog信号通路在影像椎间盘形成过程中起着核心作用，是进化保守的，在脊椎动物发育过程中也起着重要的调节作用。它的失调与人类癌症有关。

The regulation of gene expression is pivotal to the specification of cell fate and tissue differentiation in developing animals. Thus, the determination of expression patterns of all genes within an organism will be fundamental to the understanding of the regulatory network underlying its development. One of us (PT) has recently generated a large collection of RNA probes to determine by RNA in situ hybridization the expression patterns of 7590 (out of a total of about 14.000) genes in the Drosophila melanogaster embryo. This analysis has revealed a great variety of expression patterns reflecting the cellular complexity of the embryo. Here, we propose to use our large collection of RNA probes to comprehensively determine gene expression patterns in larval imaginal discs, simple epithelia that are frequently used as model tissues to study developmental mechanisms. Our aims are twofold: First, the broad aims are to provide an unbiased overview of gene expression regulation in an epithelial tissue undergoing patterning decisions and to decipher the regulatory network underlying its development. Second, our more specific aim is to identify, based on their expression pattern, novel target genes of the Hedgehog signal transduction pathway. The Hedgehog signaling pathway plays central role in imaginal disc patterning, it is evolutionary conserved and plays important regulatory roles also during vertebrate development. Its mis-regulation is associated with cancers in humans.