PNAS：斑马鱼条纹源自细胞追逐游戏

细胞的追赶游戏可以帮助形成斑马鱼身上的标志性条纹。两种皮肤细胞——黑色素细胞和黄色素细胞之间的联系促使黑色素细胞移动，而黄色素细胞则对其穷追不舍。发育生物学家日前将研究报告在线发表于美国《国家科学院院刊》（PNAS）上。

研究人员的模型表明，这种相互作用导致色素细胞分离形成斑马鱼的不同颜色的条纹。为了了解细胞间的互动如何引起了条纹或者斑点皮肤，科学家找到了一种方法，可以将来自于斑马鱼尾翼的色素细胞在培养皿中进行培养。相同类型的色素细胞似乎并不会相互作用。不过，当黄色素细胞与黑色素细胞相互靠近时，黄色素细胞会移动去接触黑色素细胞。而黑色素细胞会因此后退，跑得更远。黄色素细胞则并不“气馁”，继续追随。

来自于斑马鱼突变体的细胞有着更宽、更模糊的条纹，它的细胞行为表现也不同。其黑色素细胞并不会远离黄色素细胞，黄色素细胞也不会热烈地追赶它们。研究人员称，该情况可以解释其条纹模糊的边界处，黄色素细胞与黑色素细胞的混合种群。

研究团队尚未观测发育中的斑马鱼的细胞运动，但是新研究也许能解释为何可生成细胞膜蛋白质的基因突变会导致产生不同的皮肤类型。它还能帮助解释其他动物（如斑马、猎豹、美洲豹或者斑点狗）的皮肤类型是如何形成的。

英文摘要推荐

Proceedings of the National Academy of the Sciences of the United States of America               doi: 10.1073/pnas.1315416111

In vitro analysis suggests that difference in cell movement during direct interaction can generate various pigment patterns in vivo

Hiroaki Yamanaka and Shigeru Kondo1

Pigment patterns of organisms have invoked strong interest from not only biologists but also， scientists in many other fields. Zebrafish is a useful model animal for studying the mechanism of pigment pattern formation. The zebrafish stripe pattern is primarily two types of pigment cells： melanophores and xanthophores. Previous studies have reported that interactions among these pigment cells are important for pattern formation. In the recent report， we found that the direct contact by xanthophores induces the membrane depolarization of melanophores. From analysis of jaguar mutants， it is suggested that the depolarization affects the movements of melanophores. To analyze the cell movement in detail， we established a unique in vitro system. It allowed us to find that WT xanthophores induced repulsive movement of melanophores through direct contact. The xanthophores also chased the melanophores. As a result， they showed run-and-chase movements. We also analyzed the cell movement of pigment cells from jaguar and leopard mutants， which have fuzzy stripes and spot patterns， respectively. jaguar cells showed inhibited run-and-chase movements， and leopard melanophores scarcely showed repulsive response. Furthermore， we paired mutant and WT cells and showed which of the melanophores and xanthophores have responsibility for the altered cell movements. These results suggested that there is a correspondence relationship between the cell movements and pigment patterns. The correspondence relationship highlighted the importance of the cell movements in the pattern formation and showed that our system is a quite useful system for future study in this field.