Analysis of Blastoderm-Specific Genes in Drosophila

本提案的目的是了解 >Drosophila> segmentation gene >tailless>（>tll>）。 突变 表型由特征性缺陷或缺乏 节段性起源的结构位于前部和前部附近， 胚盘的外胚层区域的后面。 的 剩余的片段看起来更大。 就像已确定的“差距” 分割基因，>tll>突变体改变>ftz>胚盘条纹 格局 因此，>tll>在发育早期起作用。 但 似乎有一个独特的功能，因为没有其他的 改变胚胎两极的合子活跃基因。 虽然昆虫体节模式的发展一直是 解释的基础上产生的双重梯度， 两个独立系统的作用，没有预测到， 单个基因的产物可能参与了 两个相反的两极。 目标是利用分子 分离>tll>基因和表征其基因的技术 产品 原位杂交将在早期进行， 胚胎，以确定转录本是否定位于 突变体的前部和后部区域发生了改变。 的 转录单位将被定义和转录模式 测定 基因将被测序，抗体将被 针对融合蛋白的突变，以及 将评估其它分割基因对> T11>表达的影响。 这些实验将提供对一种独特基因的深入了解 它控制着生物体两端的分裂， 所以进入细胞决定的过程， 发展

The goal of this proposal is to understand the function of the >Drosophila> segmentation gene >tailless> (>tll>). The mutant phenotype consists of characteristic defects or absence of structures of segmental origin located near the anterior and the posterior of the ectodermal region of the blastoderm. The remaining segments appear larger. Like the identified "gap" segmentation genes, >tll> mutants alter the >ftz> blastoderm striping pattern. Hence, >tll> acts early in development. However, it appears to serve a unique function, as there are no other zygotically active genes altering both poles of the embryo. While the development of a segment pattern in insects has been explained on the basis of a double gradient resulting from the action of two separate systems, it has not been predicted that the products of a single gene might be involved in establishing the two opposite poles. The objectives are to use molecular techniques to isolate the >tll> gene and to characterize its gene product. In situ hybridizations will be carried out to early embryos to determine whether the transcript is localized to the anterior and posterior regions altered in the mutants. The transcription unit will be defined and the transcription pattern determined. The gene will be sequenced, antibodies will be raised against fusion proteins, and the effect of mutations in other segmentation genes on expression of >tll> will be assessed. The experiments will provide insight into a unique gene which controls segmentation at the two ends of an organism, and so into the process of cell determination at the onset of development.