Shoji Hiroto, Mochizuki Atsushi, Iwasa Yoh, Hirata Masashi, Watanabe Tsuyoshi, Hioki Syozo, Kondo Shigeru
Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka, Japan.
Dev Dyn. 2003 Apr;226(4):627-33. doi: 10.1002/dvdy.10277.
The formation of stripe patterns in animal skin has been explained by the reaction-diffusion (RD) system, a hypothetical chemical reaction proposed by A. Turing. Although animal stripes usually have directionality, the RD model alone cannot explain how the direction is specified. To investigate the mechanism regulating the direction of stripes, we studied stripe pattern formation in two species of Genicanthus during sexual conversion. These species share almost identical morphologic properties, except for their stripe direction. In both species, spots transiently arise at random positions and then combine and rearrange to form directional stripes. Computational analysis has shown that diffusion anisotropy is very effective at specifying the direction of stripes formed by the RD system. Model simulations reproduce the transient dynamics of directional pattern formation observed in fish as well as the resulting stripes. In cases where the magnitude and direction of diffusion anisotropy of the substances are identical, the resulting stripes are not directional. However, if they differ, stripes become directional. As only a small difference in anisotropy is required for this effect, any kind of structure with directional conformation might cause a marked change in stripe direction. Scales are the most likely candidate structure for generating anisotropic interactions in skin.
动物皮肤条纹图案的形成已由反应扩散（RD）系统解释，这是A. 图灵提出的一种假设性化学反应。尽管动物条纹通常具有方向性，但仅RD模型无法解释方向是如何确定的。为了研究调节条纹方向的机制，我们研究了两种角蝶鱼在性转变过程中的条纹图案形成。除了条纹方向外，这些物种具有几乎相同的形态特征。在这两个物种中，斑点会在随机位置短暂出现，然后合并并重新排列形成定向条纹。计算分析表明，扩散各向异性在确定由RD系统形成的条纹方向方面非常有效。模型模拟再现了在鱼类中观察到的定向图案形成的瞬态动力学以及由此产生的条纹。在物质扩散各向异性的大小和方向相同的情况下，产生的条纹没有方向性。然而，如果它们不同，条纹就会变得有方向性。由于这种效应只需要各向异性有很小的差异，任何具有定向构象的结构都可能导致条纹方向发生显著变化。鳞片是皮肤中产生各向异性相互作用最有可能的候选结构。
