Bonner J T
Department of Ecology and Evolutionary Biology, Princeton University, Princeton. NJ 08544, USA.
Proc Natl Acad Sci U S A. 1998 Aug 4;95(16):9355-9. doi: 10.1073/pnas.95.16.9355.
In the development of the cellular slime mold Dictyostelium discoideum there is a stage in which the aggregated amoebae form a migrating slug that moves forward in a polar fashion, showing sensitive orientation to environmental cues, as well as early signs of differentiation into anterior prestalk and posterior prespore cells. Heretofore it has been difficult to follow the movement of the individual cells within the slug, but a new method is described in which small, flat (one cell thick) slugs are produced in a glass-mineral oil interface where one can follow the movement of all the cells. Observations of time-lapse videos reveal the following facts about slug migration: (i) While the posterior cells move straight forward, the anterior cells swirl about rapidly in a chaotic fashion. (ii) Turning involves shifting the high point of these hyperactive cells. (iii) Both the anterior and the posterior cells move forward on their own power as the slug moves forward. (iv) There are no visible regular oscillations within the slug. (v) The number of prestalk and prespore cells is proportional for a range of sizes of these mini-slugs. All of these observations on thin slugs are consistent with what one finds in normal, three-dimensional slugs.
在细胞黏菌盘基网柄菌的发育过程中，有一个阶段，聚集的变形虫会形成一个迁移的蛞蝓体，它以极性方式向前移动，对环境线索表现出敏感的定向能力，同时也有分化为前部柄细胞和后部孢子前体细胞的早期迹象。迄今为止，追踪蛞蝓体内单个细胞的运动一直很困难，但本文描述了一种新方法，即在玻璃 - 矿物油界面中产生小而扁平（单细胞厚）的蛞蝓体，在那里可以追踪所有细胞的运动。对延时视频的观察揭示了关于蛞蝓迁移的以下事实：（i）后部细胞向前直线移动时，前部细胞以混乱的方式快速旋转。（ii）转向涉及这些活跃过度的细胞的高点移动。（iii）当蛞蝓体向前移动时，前部和后部细胞都依靠自身的力量向前移动。（iv）蛞蝓体内没有可见的规则振荡。（v）对于这些小型蛞蝓体的一系列大小，柄细胞和孢子前体细胞的数量是成比例的。所有这些关于薄蛞蝓体的观察结果与在正常的三维蛞蝓体中发现的情况一致。
