GENETIC ANALYSIS OF MYB PROTOONCOGENE FUNCTION

MYB基因在进化过程中高度保守。三个MYB- 相关基因(c-myb、A-myb和B-myb)已经在哺乳动物中被发现， 鸟类和两栖动物。C-myb基因是胎儿发育所必需的 造血和c-myb基因的改变可导致白血病和淋巴瘤 哺乳动物和鸟类。Myb蛋白是核的，与特定的DNA结合 测序和调控转录。然而，关键基因 在MYB途径的上游和下游的位置仍然未知。一个 果蝇MYB相关基因在十多年前首次被发现，但 在很大程度上仍然没有特征。我们已经证明了果蝇Myb DNA结合域识别与Myb蛋白相同的DNA序列 脊椎动物和从细胞黏液霉菌盘基网柄菌。 此外，我们最近发现，果蝇Myb的片段 蛋白质可以在功能上取代脊椎动物的同源片段- MYB蛋白在致癌转化中的作用另外，我们发现， 脊椎动物Myb蛋白与果蝇Myb蛋白同源性较高 比之前想象的要广泛。高度的进化 脊椎动物中与癌基因相关的其他途径的保护， 果蝇和线虫秀丽线虫让我们相信 MYB途径可能也是同样保守的。因此，我们现在 建议使用果蝇可用的遗传和生化工具 和线虫，以便将MYB置于遗传途径中。至 为实现这一目标，我们提出了以下具体目标： 1.确定MYB基因表达的调控模式和机制 在果蝇发育的不同阶段； 2.确定果蝇Myb蛋白是否可以作为一种 组织培养细胞和完整动物中的转录调节因子； 3.获得野生型错误表达的转基因果蝇 Myb的类型和/或突变形式导致可记分的表型； 4.使用这些表型来识别和排序增强或 抑制Myb功能； 5.识别受果蝇Myb蛋白调控的靶基因；以及 6.鉴定和鉴定MYB相关基因(S)和 线虫中的蛋白质(S)。

The myb genes have been highly conserved during evolution. Three myb- related genes (c-myb, A-myb, and B-myb) have been identified in mammals, birds, and amphibians. The c-myb gene is essential for fetal hematopoiesis and altered forms of c-myb cause leukemias and lymphomas in mammals and birds. The Myb proteins are nuclear, bind to specific DNA sequences and regulate transcription. However, the critical genes that lie upstream and downstream in the myb pathway remain unknown. A Drosophila myb-related gene was first identified over ten years ago, but remains largely uncharacterized. We have shown that the Drosophila Myb DNA-binding domain recognizes the same DNA sequence as Myb proteins from vertebrates and from the cellular slime mold Dictyostelium discoideum. Furthermore, we have recently shown that segments of the Drosophila Myb protein can functionally replace homologous segments of the vertebrate v- Myb protein in oncogenic transformation. In addition, we have found that the homology among vertebrate Myb proteins and Drosophila Myb is more extensive than previously appreciated. The high degree of evolutionary conservation of other oncogene-related pathways among vertebrates, Drosophila, and the nematode Caenorhabditis elegans leads us to believe that the myb pathway may be similarly conserved. Therefore, we now propose to use the genetic and biochemical tools available in Drosophila and C. elegans in order to place myb within a genetic pathway. To accomplish this goal, we propose the following specific aims: 1. To determine the pattern and mechanism of regulation of myb expression in Drosophila during various stages of development; 2. To determine if the Drosophila Myb protein can function as a transcriptional regulator in tissue culture cells and in intact animals; 3. To create transgenic Drosophila in which the misexpression of wild type and/or mutant forms of Myb cause scoreable phenotypes; 4. To use these phenotypes to identify and order genes that enhance or suppress Myb function; 5. To identify target genes regulated by the Drosophila Myb protein; and, 6. To identify and characterize the expression of myb-related gene(s) and protein(s) in C. elegans.