Egfr signalling defines a protective function for ommatidial orientation in the Drosophila eye
Egfr signalling defines a protective function for ommatidial orientation in the Drosophila eye
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DOI：
10.1242/dev.00773
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发表时间：
2003-11-01
期刊：
影响因子：
4.6
通讯作者：
Freeman, M
中科院分区：
文献类型：
--
作者：
Brown, KE;Freeman, M
果蝇眼睛的小眼旋转提供了一个引人注目的例子，说明组织图案可以精确地实现。成年人的小眼与赤道成直角排列，背侧和腹侧的小眼指向相反的方向。这种模式是在盘发育过程中建立的，当集群旋转90度时，这一过程取决于平面细胞极性和旋转特异性因素，如尼莫和斯卡布鲁斯。在这里，我们证明了需要表皮生长因子受体（Egfr）信号在旋转，进一步增加了这一途径在眼睛发育中的多种作用。Egfr与其他旋转因子的不同之处在于，初始过程不受影响，但当信号异常时，成人的方向会受到极大的干扰。我们建议，Egfr信号行为在第三龄成虫盘“锁定”小眼在其最终位置，在它的情况下，小眼的方向成为破坏幼虫盘到成人的眼睛重塑。这种锁定可以通过改变细胞的粘附特性来实现：基于钙粘蛋白的粘附对于小眼保持在其适当的位置是重要的。此外，我们有证据表明，有一个错误的纠正机制，在蛹阶段重新定位不适当的定向小眼。我们的研究结果表明，初始图案化事件不足以实现蝇眼的精确结构，并强调了纠错的新要求，以及EGFR依赖的保护功能，以防止组织重塑过程中的形态破坏。
Ommatidial rotation in the Drosophila eye provides a striking example of the precision with which tissue patterning can be achieved. Ommatidia in the adult eye are aligned at right angles to the equator, with dorsal and ventral ommatidia pointing in opposite directions. This pattern is established during disc development, when clusters rotate through 90degrees, a process dependent on planar cell polarity and rotation-specific factors such as Nemo and Scabrous. Here, we demonstrate a requirement for epidermal growth factor receptor (Egfr) signalling in rotation, further adding to the manifold actions of this pathway in eye development. Egfr is distinct from other rotation factors in that the initial process is unaffected, but orientation in the adult is greatly disrupted when signalling is abnormal. We propose that Egfr signalling acts in the third instar imaginal disc to 'lock' ommatidia in their final position, and that in its absence, ommatidial orientation becomes disrupted during the remodelling of the larval disc into an adult eye. This lock may be achieved by a change in the adhesive properties of the cells: cadherin-based adhesion is important for ommatidia to remain in their appropriate positions. In addition, we have evidence that there is an error-correction mechanism operating during pupal stages to reposition inappropriately orientated ommatidia. Our results suggest that initial patterning events are not sufficient to achieve the precise architecture of the fly eye, and highlight a novel requirement for error-correction, and for an Egfr-dependent protection function to prevent morphological disruption during tissue remodelling.