Laboratory of Artificial & Natural Evolution (LANE), Dept. of Genetics & Evolution, University of Geneva, Geneva, Switzerland.
SIB Swiss Institute of Bioinformatics, Geneva, Switzerland.
Nat Commun. 2021 Apr 23;12(1):2433. doi: 10.1038/s41467-021-22525-1.
We previously showed that the adult ocellated lizard skin colour pattern is effectively generated by a stochastic cellular automaton (CA) of skin scales. We additionally suggested that the canonical continuous 2D reaction-diffusion (RD) process of colour pattern development is transformed into this discrete CA by reduced diffusion coefficients at the borders of scales (justified by the corresponding thinning of the skin). Here, we use RD numerical simulations in 3D on realistic lizard skin geometries and demonstrate that skin thickness variation on its own is sufficient to cause scale-by-scale coloration and CA dynamics during RD patterning. In addition, we show that this phenomenon is robust to RD model variation. Finally, using dimensionality-reduction approaches on large networks of skin scales, we show that animal growth affects the scale-colour flipping dynamics by causing a substantial decrease of the relative length scale of the labyrinthine colour pattern of the lizard skin.
我们之前表明，成年眼斑蜥蜴的皮肤颜色图案是通过皮肤鳞片的随机元胞自动机（CA）有效地生成的。我们还提出，经典的连续二维反应-扩散（RD）颜色图案发展过程通过鳞片边界处扩散系数的降低转化为这种离散 CA（由皮肤的相应变薄证明）。在这里，我们在真实蜥蜴皮肤的几何形状上进行 3D 的 RD 数值模拟，并证明仅皮肤厚度的变化就足以导致 RD 图案形成过程中的鳞片尺度的着色和 CA 动力学。此外，我们表明这种现象对 RD 模型的变化具有鲁棒性。最后，通过对皮肤鳞片的大网络进行降维方法，我们表明动物生长通过导致蜥蜴皮肤的迷宫状颜色图案的相对长度尺度显著减小，从而影响鳞片颜色翻转的动力学。
