During embryo development, patterns of protein concentration appear in response to morphogen gradients. These patterns provide spatial and chemical information that directs the fate of the underlying cells. Here, we emulate this process within non-living matter and demonstrate the autonomous structuration of a synthetic material. First, we use DNA-based reaction networks to synthesize a French flag, an archetypal pattern composed of three chemically distinct zones with sharp borders whose synthetic analogue has remained elusive. A bistable network within a shallow concentration gradient creates an immobile, sharp and long-lasting concentration front through a reaction–diffusion mechanism. The combination of two bistable circuits generates a French flag pattern whose ‘phenotype’ can be reprogrammed by network mutation. Second, these concentration patterns control the macroscopic organization of DNA-decorated particles, inducing a French flag pattern of colloidal aggregation. This experimental framework could be used to test reaction–diffusion models and fabricate soft materials following an autonomous developmental programme.

中文翻译：

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反应扩散法国国旗图案的合成与物化

在胚胎发育过程中，蛋白质浓度的模式响应形态发生子梯度而出现。这些模式提供了指导下层细胞命运的空间和化学信息。在这里，我们在非生命物质中模拟了此过程，并演示了合成材料的自主结构。首先，我们使用基于DNA的反应网络来合成法国国旗，这是一个原型模式，由三个化学性质不同的区域组成，这些区域具有清晰的边界，其合成类似物仍然难以捉摸。浓度梯度较小的双稳态网络通过反应扩散机制产生了固定的，尖锐的和持久的浓度前沿。两个双稳态电路的组合产生了一个法国国旗图案，其“表型”可以通过网络突变重新编程。第二，这些浓度模式控制着装饰有DNA的颗粒的宏观组织，从而诱导了胶体聚集的French flag模式。该实验框架可用于测试反应扩散模型并按照自主开发程序制造软材料。