Identification and characterization of genes encoding proteins with polar expression in different Drosophila cells

在所有生物体中，细胞的极性关键取决于经常是极化的局部决定因素和细胞骨架的极化组织的相互作用。在过去，遗传方法已经确定了几个组织极性细胞的关键角色，如Inscuteable，Crumbs，Bazooka和Stardust。随后，针对编码蛋白产生的抗体的使用揭示了它们在固定材料中的极性定位。事实证明，这些工具在分析发育中的有机体中的细胞行为方面非常有价值。然而，为了充分了解极化细胞的产生和维持，有必要使用GFP标记的蛋白质，这将允许在体内分析细胞极性的动态调节。此外，我们必须寻找更多的基因来编码具有极性分布的蛋白质。鉴定这种蛋白质的一种方法是使用随机的GFP标签方法(Morin等人，2001年)。在这里，一个含有外显子的绿色荧光蛋白被插入到基于转座子的载体中，它被偶然地引入到内源苍蝇基因的一个内含子中。剪接后，融合蛋白被产生(取决于融合框架)，通常被运输到其正常的亚细胞定位。一旦确定了特定的亚细胞表达模式，基因的突变很容易通过不精确的转座子切除而产生。遗传学和细胞生物学的这种强大的结合将为在广泛的组织中调节细胞极性的机制提供新的见解。

In all organisms cell polarity crucially depends on the interplay of often-polar localized determinants and a polarized organization of the cytoskeleton. In the past, genetic approaches have identified several key players organizing polar cells such as Inscuteable, Crumbs, Bazooka and Stardust. Subsequently, the use of antibodies generated against the encoded proteins revealed their polar localization in fixed material. These tools turned out to be extremely valuable in analyzing cell behaviour in the context of a developing organism. Howver, to fully understand the generation and maintenance of polarized cells it will be necessary to use GFP-tagged proteins which will allow in vivo analyses of the dynamic regulation of cell polarity. In addition, we have to seek additional genes that encode proteins with a polar distribution. One way to identify such proteins is to use a random GFPtagging approach (Morin et al., 2001). Here, A GFP containing exon, which is inserted in a transposon based vector, is introduced by chance into an intron of an endogenous fly gene. Following splicing a fusion protein is generated (depending on the fusion frame) that is generally transported to its normal subcellular localization. Once a specific subcellular expression pattern is defined, mutations in the gene can be easily generated by imprecise excision of the transposon. This powerful combination of genetics and cell biology will provide new insights into the mechanisms that regulate cell polarity in a broad range of tissues.