Fingerprints are complex and individually unique patterns in the skin. Established prenatally, the molecular and cellular mechanisms that guide fingerprint ridge formation and their intricate arrangements are unknown. Here we show that fingerprint ridges are epithelial structures that undergo a truncated hair follicle developmental program and fail to recruit a mesenchymal condensate. Their spatial pattern is established by a Turing reaction-diffusion system, based on signaling between EDAR, WNT, and antagonistic BMP pathways. These signals resolve epithelial growth into bands of focalized proliferation under a precociously differentiated suprabasal layer. Ridge formation occurs as a set of waves spreading from variable initiation sites defined by the local signaling environments and anatomical intricacies of the digit, with the propagation and meeting of these waves determining the type of pattern that forms. Relying on a dynamic patterning system triggered at spatially distinct sites generates the characteristic types and unending variation of human fingerprint patterns.

指纹是皮肤上复杂且独特的图案。产前建立的指导指纹脊形成及其复杂排列的分子和细胞机制尚不清楚。在这里，我们表明指纹脊是上皮结构，它经历了截断的毛囊发育程序并且无法募集间充质凝结物。它们的空间模式由图灵反应扩散系统建立，基于 EDAR、WNT 和拮抗 BMP 通路之间的信号。这些信号将上皮生长分解为早熟分化的基底层下的聚焦增殖带。脊形成作为一组波从局部信号环境和手指的解剖学复杂性定义的可变起始点传播而发生，这些波的传播和相遇决定了形成的图案类型。依靠在空间不同位置触发的动态模式系统生成人类指纹模式的特征类型和无休止的变化。