REGULATION OF THE DROSOPHILA SEGMENTATION GENE RUNT

果蝇胚胎分割模式的建立 被调查。强大的经典和分子遗传技术 在这个系统中可用使这成为一个很好的调查模型 多细胞生物体中体型形成的机制。 这些研究将提供对早期 并可能影响我们对出生本质的理解 缺陷。 该提案的重点是定义矮小基因的作用。这是 果蝇发育早期正常所需的基因之一 分段。这些片段基因被分成三类 上课。基因实验揭示了调控的层级 这些类与信息流之间的交互 “间隙”基因通过“配对规则”基因，最终到达片段- “极性”基因。矮小是一个配对控制的基因，已被称为 配对统治基因，因为它在调节所有其他基因方面起着关键作用 配对统治基因。就像其他人一样，矮子展示了一种配对规则 胚胎期的表达模式，因为矮小的原发 重要的是要了解这种表达模式是如何 已生成。我们将确定矮小基因的顺式调控元件， 对于其适当的监管是至关重要的。这将通过以下方式完成 胚系转化法检测DNA元件的调控 效果。调节矮小的反式作用因素将是 通过遗传和生化实验鉴定及其作用机制 的调节将在体外进行研究。 这项提案的另一个主要方面涉及侏儒的功能 蛋白质本身以及它如何调节其他基因。重要的是 这个问题是通过观察矮子不同于所有 其他早期作用的调控片段基因，似乎编码一种 分泌的糖蛋白而不是核转录因子。我们会 确定矮小蛋白的亚细胞定位并研究 翻译后修饰在调节其活动中的作用。 矮小蛋白功能的体外测试将用于 探讨其作用机制。蛋白质的重要部分 将通过对一组突变体进行测序来确定其功能 Runt的等位基因以及从其他物种分离的Runt同源物的测序 物种。最后，将使用生化和遗传方法来 确定与矮小蛋白相互作用的因素并研究它们的 在调节侏儒的调节活动中扮演的角色。这是一个多学科的 方法应该提供对侏儒在 细分，并将大大有助于我们理解 这是一个基本的生物过程。

The establishment of the segmentation pattern in Drosophila embryos will be investigated. The powerful classical and molecular genetic techniques available in this system make this an excellent model for investigating the mechanism of body pattern formation in a multicellular organism. These studies will provide insight into fundamental aspects of early development and could impact on our understanding of the nature of birth defects. The proposal focuses on defining the role of the runt gene. This is the one of the genes required early in Drosophila development for normal segmentation. These segmentation genes have been grouped into three classes. Genetic experiments reveal a hierarchy of regulatory interactions between these classes with the flow of information going from the "gap" genes through the "pair-rule" genes and finally to the segment- polarity" genes. Runt is a pair-rule gene and has been termed a primary pair-rule gene because of its key role in regulating all of the other pair-rule genes. As is the case for the others, runt shows a pair-rule pattern of expression at the blastoderm stage, because of runt's primary role it is important to understand how this pattern of expression is generated. We will identify cis-regulatory elements of the runt gene that are critical for its proper regulation. This will be accomplished using germ-line transformation to assay DNA elements for their regulatory effects. Trans-acting factors involved in regulating runt will be identified through genetic and biochemical experiments and the mechanism of regulation will be investigated in vitro. The other major aspect of this proposal addresses the function of the runt protein itself and how it acts to regulate other genes. The importance of this issue is emphasized by the observation that runt is unlike all of the other early-acting regulatory segmentation genes and appears to encode a secreted glycoprotein instead of a nuclear transcription factor. We will determine the subcellular localization of the runt protein and investigate the role post-translational modifications play in regulating its activity. An in vitro assay for the function of the runt protein will be used to investigate its mechanism of action. Portions of the protein important for function will be identified by sequencing a collection of mutant alleles of runt and also by sequencing runt homologs isolated from other species. Finally, both biochemical and genetic methods will be used to identify factors that interact with the runt protein and investigate their roles in mediating runt's regulatory activity. This multidisciplinary approach should provide important insight into the role of runt in segmentation and will contribute significantly to our understanding of this basic biological process.