Montrasio Silvia, Mlodzik Marek, Fanto Manolis
Dulbecco Telethon Institute, DIBIT, San Raffaele Scientific Institute, Milan, Italy.
Dev Dyn. 2007 Oct;236(10):2936-42. doi: 10.1002/dvdy.21328.
The precise orientation of the ommatidia in the Drosophila eye is achieved through a specialized process of cell migration taking place in the third-instar eye imaginal disc when ommatidial clusters rotate by 90 degrees. This process is strictly coordinated with the establishment of planar cell polarity (PCP), but it relies on a specific set of genes that control its mechanism independently from PCP signaling. Recently, the epidermal growth factor receptor (EGFR) pathway has been implicated in determining ommatidial rotation. We have isolated a new allele of echinus, a gene known to control the patterning and number of interommatidial cells. We show that echinus displays defects in the rotation of ommatidia that are not evident until mid-pupal stages, and we propose that echinus action is that of opposing EGFR by an unknown mechanism and that this can explain both its influence in ommatidial rotation and lattice programmed cell death (PCD).
果蝇眼中小眼的精确取向是通过在三龄眼成虫盘发生的一种特殊细胞迁移过程实现的，此时小眼簇会旋转90度。这个过程与平面细胞极性（PCP）的建立严格协调，但它依赖于一组特定的基因，这些基因独立于PCP信号传导来控制其机制。最近，表皮生长因子受体（EGFR）途径被认为与确定小眼旋转有关。我们分离出了海胆的一个新等位基因，海胆是一个已知控制小眼间细胞的模式和数量的基因。我们发现海胆在小眼旋转方面存在缺陷，这些缺陷直到蛹中期才明显，并且我们提出海胆的作用是通过一种未知机制对抗EGFR，这可以解释其对小眼旋转和晶格程序性细胞死亡（PCD）的影响。
