Sawai Satoshi, Thomason Peter A, Cox Edward C
Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA.
Nature. 2005 Jan 20;433(7023):323-6. doi: 10.1038/nature03228.
Nutrient-deprived Dictyostelium amoebae aggregate to form a multicellular structure by chemotaxis, moving towards propagating waves of cyclic AMP that are relayed from cell to cell. Organizing centres are not formed by founder cells, but are dynamic entities consisting of cores of outwardly rotating spiral waves that self-organize in a homogeneous cell population. Spiral waves are ubiquitously observed in chemical reactions as well as in biological systems. Although feedback control of spiral waves in spatially extended chemical reactions has been demonstrated in recent years, the mechanism by which control is achieved in living systems is unknown. Here we show that mutants of the cyclic AMP/protein kinase A pathway show periodic signalling, but fail to organize coherent long-range wave territories, owing to the appearance of numerous spiral cores. A theoretical model suggests that autoregulation of cell excitability mediated by protein kinase A acts to optimize the number of signalling centres.
营养匮乏的盘基网柄菌变形虫通过趋化作用聚集形成多细胞结构，朝着细胞间传递的环状单磷酸腺苷（cAMP）传播波移动。组织中心不是由创始细胞形成的，而是由向外旋转的螺旋波核心组成的动态实体，这些核心在均匀的细胞群体中自我组织。螺旋波在化学反应以及生物系统中普遍存在。尽管近年来已经证明了在空间扩展的化学反应中对螺旋波的反馈控制，但在生物系统中实现控制的机制尚不清楚。在这里，我们表明，环状单磷酸腺苷/蛋白激酶A途径的突变体显示出周期性信号，但由于出现大量螺旋核心，无法组织连贯的长程波区域。一个理论模型表明，由蛋白激酶A介导的细胞兴奋性的自动调节作用是优化信号中心的数量。
