Teleost fish of the genus Danio are excellent models to study the genetic and cellular bases of pigment pattern variation in vertebrates. The two sister species Danio rerio and Danio aesculapii show divergent patterns of horizontal stripes and vertical bars that are partly caused by the evolution of the potassium channel gene kcnj13. In D. rerio, kcnj13 is required in melanophores for interactions with xanthophores and iridophores, which cause location-specific pigment cell shapes and thereby influence colour pattern and contrast. Here, we show that cis-regulatory rather than protein coding changes underlie kcnj13 evolution between the two species. D. aesculapii express lower kcnj13 levels and exhibit low-contrast patterns similar to D. rerio mutants. Our results suggest that homotypic and heterotypic interactions between the pigment cells and their shapes diverged between species by quantitative changes in kcnj13 expression during pigment pattern diversification.

中文翻译：

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丹尼奥鱼色素模式多样化过程中钾通道基因 kcnj13 的顺式调控进化

Danio属的硬骨鱼是研究脊椎动物色素模式变异的遗传和细胞基础的优秀模型。斑马鱼和斑马鱼这两个姊妹物种显示出不同的水平条纹和垂直条纹图案，这部分是由钾通道基因kcnj13的进化引起的。在D. rerio中，黑色素细胞需要kcnj13才能与黄色细胞和虹彩细胞相互作用，这会导致特定位置的色素细胞形状，从而影响颜色模式和对比度。在这里，我们表明顺式调节而不是蛋白质编码变化是两个物种之间kcnj13进化的基础。D. aesculapii表达较低的kcnj13水平并表现出类似于D. rerio突变体的低对比度模式。我们的研究结果表明，在色素模式多样化过程中，通过kcnj13表达的定量变化，色素细胞及其形状之间的同型和异型相互作用在物种之间存在差异。