Eye Development: Molecular Genetics of Nuclear Migration

本文拟对果蝇复眼光感受器核迁移发育调控所需的基因和基因产物进行表征。核迁移在动物发育中具有普遍的重要性。例如，人类大脑紊乱，无脑畸形，是大脑发育过程中神经核未能适当迁移的结果。此外，与人类无脑畸形基因同源的果蝇基因Lis1对果蝇的光感受器核迁移至关重要。因此，将被鉴定和研究的基因和蛋白质与人类发育和疾病直接相关。核迁移是一个重要的现象，也因为它的关系，其他关键过程在真核生物的发展。许多对核迁移很重要的蛋白质也需要其他细胞器的运输，细胞极性的建立，以及细胞内形态素的定位。该研究提出了四个具体目标。首先是光感受器核迁移所需的蛋白质Klarsicht的结构/功能分析。表达部分Klarsicht蛋白的转基因果蝇将用于将亚细胞定位、蛋白质结合和细胞器迁移功能与蛋白质结构联系起来。第二个目标是克隆和表征egk1基因，该基因与克拉希特一样，对光感受器核迁移至关重要。第三，针对多种蛋白质的抗体将会被用来将四个核迁移基因klarsicht， egk1， BicD和DLis-1排序到一个通路中。此外，Klarsicht和Egk1蛋白之间的物理相互作用的可能性将通过体内和体外实验进行探索。最后，将使用各种不同的遗传筛选方法来鉴定klarsicht/egk1通路中的其他基因。

It is proposed to characterize the genes and gene products required for developmentally regulated nuclear migrations in photoreceptors of the Drosophila compound eye. Nuclear migration is of universal importance in animal development. For example, the human brain disorder, Lissencephaly, is the result of neural nuclei failing to migrate appropriately during brain development. Moreover, the Drosophila homolog of the human Lissencephaly gene, Lis1, is essential for photoreceptor nuclear migrations in Drosophila. Thus, the genes and proteins that will be identified and studied are directly relevant to human development and disease. Nuclear migration is an important phenomenon to understand also because of its relationship to other critical processes in eukaryotic development. Many of the proteins important for nuclear migration are also required for the transport of other organelles, establishment of cell polarity, and morphogen localization within the cell. There are four specific goals of the research proposed. The first is a structure/function analysis of Klarsicht, a protein required for photoreceptor nuclear migration. Transgenic flies expressing partial Klarsicht proteins will be used to correlate subcellular localization, protein binding, and organelle migration functions with protein structure. The second aim is to clone and characterize the egk1 gene, which like klarsicht, is essential for photoreceptor nuclear migration. Thirdly, antibodies to a variety of proteins will be used to order four nuclear migration genes, klarsicht, egk1, BicD and DLis-1, into a pathway. In addition, the possibility of physical interactions between Klarsicht and Egk1 proteins will be explored using in vivo and in vitro assays. Finally, a variety of different genetic screening approaches will be used to identify additional genes in the klarsicht/egk1 pathway.