Pichaud Franck
Medical Research Council, Laboratory for Molecular Cell Biology, University College London, London, United Kingdom.
Front Cell Neurosci. 2018 Mar 29;12:90. doi: 10.3389/fncel.2018.00090. eCollection 2018.
The fly photoreceptor has long been used as a model to study sensory neuron morphogenesis and retinal degeneration. In particular, elucidating how these cells are built continues to help further our understanding of the mechanisms of polarized cell morphogenesis, intracellular trafficking and the causes of human retinal pathologies. The conserved PAR complex, which in flies consists of Cdc42-PAR6-aPKC-Bazooka, and the transmembrane protein Crumbs (Crb) are key players during photoreceptor morphogenesis. While the PAR complex regulates polarity in many cell types, Crb function in polarity is relatively specific to epithelial cells. Together Cdc42-PAR6-aPKC-Bazooka and Crb orchestrate the differentiation of the photoreceptor apical membrane (AM) and , thus allowing these cells to assemble into a neuro-epithelial lattice. In addition to its function in epithelial polarity, Crb has also been shown to protect fly photoreceptors from light-induced degeneration, a process linked to Rhodopsin expression and trafficking. Remarkably, mutations in the human (CRB1) gene lead to retinal degeneration, making the fly photoreceptor a powerful disease model system.
果蝇光感受器长期以来一直被用作研究感觉神经元形态发生和视网膜变性的模型。特别是，阐明这些细胞是如何构建的，继续有助于我们进一步理解极化细胞形态发生、细胞内运输机制以及人类视网膜病变的原因。保守的PAR复合物在果蝇中由Cdc42 - PAR6 - aPKC - 巴祖卡组成，跨膜蛋白Crb（Crb）是光感受器形态发生过程中的关键参与者。虽然PAR复合物在许多细胞类型中调节极性，但Crb在极性方面的功能相对特定于上皮细胞。Cdc42 - PAR6 - aPKC - 巴祖卡和Crb共同协调光感受器顶端膜（AM）的分化，从而使这些细胞组装成神经上皮晶格。除了其在上皮极性中的功能外，Crb还被证明可以保护果蝇光感受器免受光诱导的变性，这一过程与视紫红质的表达和运输有关。值得注意的是，人类CRB1基因突变会导致视网膜变性，这使得果蝇光感受器成为一个强大的疾病模型系统。
