The role of the gene bozooka during asymmetric division of neural stem cells in Drosophila

典型的干细胞分裂是不对称的，产生两个不同发育潜力的子细胞。在大多数情况下，一个子细胞采用祖细胞的命运，将产生经历终末分化的细胞，而另一个子细胞保持干细胞的全部潜力。果蝇中枢神经系统的干细胞，被称为神经母细胞，不对称分裂，并在每次分裂中产生神经节母细胞（神经元祖细胞）和另一个神经母细胞。我们已经确定了两个基因，bazooka和DaPKC，它们对于细胞命运决定因素的不对称定位和神经母细胞有丝分裂纺锤体的正确定向是必不可少的。这两个基因编码进化上高度保守的PAR/aPKC复合体的核心成分。在这个项目中，我们研究了Bazooka蛋白的哪些区域对控制不对称神经母细胞分裂有重要的功能。为此，我们利用转基因果蝇在体内分析了几种通过体外诱变产生的Bazooka突变体的亚细胞定位和功能。此外，我们在眼睛中使用显性过表达表型作为基因筛选的读数，以分离bazooka的点突变，并确定与bazooka功能相互作用的基因。

Typical stem cell divisions are asymmetric and produce two daughter cells different developmental potential. In most cases, one daughter cell adopts a progenitor fate and will produce cells that undergo terminal differentiation, while the other daughter cell maintains the full potential of a stem cell. The stem cells of the Drosophila central nervous system, so called neuroblasts, divide asymmetrically and give rise to a ganglion mother cell (a neuronal progenitor cell) and another neuroblast in each division. We have identified two genes, bazooka and DaPKC, that are indispensable for asymmetric localization of cell fate determinants and for correct orientation of the mitotic spindle in neuroblasts. Both genes encode core components of the evolutionarily highly conserved PAR/aPKC complex. In the proposed project we investigate which regions of the Bazooka protein are functionally important for the control of asymmetric neuroblast division. To this aim, we assay the subcellular localization and functionality of several mutant versions of Bazooka generated by in vitro mutagenesis in vivo using transgenic flies. In addition, we use a dominant overexpression phenotype in the eye as a readout for a genetic screen to isolate point mutations in bazooka and to identify genes that functionally interact with bazooka.