REGULATION AND FUNCTION OF THE DROSOPHILA GENE RUNT

果蝇胚胎分割模式的建立， 追究 强大的经典和分子遗传技术 这是一个很好的研究模型， 多细胞生物体中体型形成的机制。 这些研究将提供洞察的基本方面， 可能会影响我们对出生本质的理解 缺陷 该提案的重点是定义侏儒基因的作用。 这是 果蝇早期发育所需的基因之一， 细分 这些分割基因被分为三组 班 遗传实验揭示了一个层次的调节 这些类之间的相互作用， “间隙”基因通过“配对规则”基因，最后到片段- 极性”基因。 Runt是一个成对规则基因， 配对规则基因，因为它在调节所有其他基因中起着关键作用， 配对规则基因 和其他人一样，runt也表现出配对规则 在胚盘阶段的表达模式，因为runt的主要 重要的是要了解这种表达模式是如何 生成的. 我们将鉴定runt基因的顺式调节元件， 对它的正确管理至关重要。 这将通过使用 生殖系转化以测定DNA元件的调控 方面的影响. 参与调节runt的反式作用因子将是 通过遗传和生物化学实验确定， 将在体外进行研究。 这个建议的另一个主要方面是解决了矮小的功能 蛋白质本身以及它如何调节其他基因。 的重要性 这个问题是强调的观察，runt是不同于所有的 其他早期作用的调控节段基因，似乎编码一个 分泌糖蛋白而不是核转录因子。 我们将 确定runt蛋白的亚细胞定位并研究 翻译后修饰在调节其活性中的作用。 将使用用于runt蛋白功能的体外测定来确定 研究其作用机制。 蛋白质的重要部分 将通过对一组突变体进行测序来鉴定其功能。 也可以通过对从其他基因中分离的runt同源物进行测序， 物种 最后，生物化学和遗传学方法将用于 确定与runt蛋白相互作用的因素，并研究其 在调节runt的调节活动中的作用。 这种多学科 这种方法应该提供重要的洞察力的作用，矮小， 这将有助于我们更好地理解 这个基本的生物过程。

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.