A primary role for the epidermal growth factor receptor in ommatidial spacing in the Drosophila eye
A primary role for the epidermal growth factor receptor in ommatidial spacing in the Drosophila eye
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DOI：
10.1016/s0960-9822(01)00125-7
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发表时间：
2001-03-20
期刊：
影响因子：
9.2
通讯作者：
Freeman, M
中科院分区：
文献类型：
--
作者：
Baonza, A;Casci, T;Freeman, M
背景：上皮内规则间隔结构的分化是发育模式形成的共同特征。果蝇眼睛成像盘中小眼的规则间距为这一现象提供了一个很好的模型。在果蝇复眼中，正确的小眼间距是建立准确的六角形小眼图案的核心事件。R8光感受器是组成成人眼的每一个小眼的创始细胞，由bHLH转录因子Atonal指定。结果：我们发现表皮生长因子受体(EGFR)在调节R8间距方面具有主要功能。该受体在新生小眼内的激活诱导了一种分泌的抑制物的表达，从而阻止了附近细胞的无调性表达，从而阻止了小眼的启动。分泌抑制物的身份仍然难以捉摸，但与先前的建议相反，我们表明它不是Argos。这种依赖于EGFR的抑制作用与分泌的粗糙蛋白对纳洛酮的抑制作用平行。EGFR途径的激活依赖于菱形蛋白-1表达的无调性功能。我们的结果还允许我们得出结论，EGFR在促进细胞存活方面的作用在很大程度上独立于它在光感受器招募中的作用；即使细胞死亡被阻止，大多数光感受器也无法形成。结论：基于我们和其他人的数据，我们提出了一个R8间隔的模型，该模型包含一个自组织的信号分子网络。这个模型描述了连续的小眼行是如何彼此异相形成的，从而导致复眼中小平面的六角形阵列。
Background: The differentiation of regularly spaced structures within an epithelium is a common feature of developmental pattern formation. The regular spacing of ommatidia in the Drosophila eye imaginal disc provides a good model for this phenomenon. The correct spacing of ommatidia is a central event in establishing the precise hexagonal pattern of ommatidia in the Drosophila compound eye. The R8 photoreceptors are the founder cells of each of the ommatidia that comprise the adult eye and are specified by a bHLH transcription factor, Atonal.Results: We find that the epidermal growth factor receptor (Egfr) has a primary function in regulating R8 spacing. The receptor's activation within nascent ommatidia induces the expression of a secreted inhibitor that blocks atonal expression, and therefore ommatidial initiation, in nearby cells. The identity of the secreted inhibitor remains elusive but, contrary to previous suggestions, we show that it is not Argos. This Egfr-dependent inhibition acts in parallel to the inhibition of atonal by the secreted protein Scabrous. The activation of the Egfr pathway is dependent on Atonal function via the expression of Rhomboid-1. Our results also allow us to conclude that Egfr's role in promoting cell survival is largely independent of its role in photoreceptor recruitment; even when cell death is blocked, most photoreceptors fail to form.Conclusions: Based on our data and those of others, we propose a model for R8 spacing that comprises a self-organizing network of signaling molecules. This model describes how successive rows of ommatidia form out of phase with each other, leading to the hexagonal array of facets in the compound eye.