Sternfeld John, O'Mara Ryan
Department of Biological Sciences, State University of New York, Cortland, NY 13045, USA.
Dev Growth Differ. 2005 Jan;47(1):49-58. doi: 10.1111/j.1440-169x.2004.00778.x.
The Dictyostelium slug lays down curved marks in its slime sheath trail as it migrates across an agar substrate. These 'footprints' are caused by elevation of the slug anterior as it initiates a period of aerial migration and can be used as a measure of the slug's propensity for this behavior. A variety of factors have been found to affect the number of footprints created per distance migrated. Smaller slugs produce a higher incidence of footprints than larger slugs. Migration in the light and lower temperatures during migration increase footprint incidence. Activated charcoal reduces, while exogenous addition of ammonia increases, the incidence of footprints. Simulation of the three-dimensional (3D) environment of the soil suggests that aerial migration plays a role in the slug's movement through the cavities of its natural environment. A model proposes that aerial migration is initiated by a small group of continually changing prestalk cells that acts as a pacemaker and is moved around the circumference of the slug tip by the rotation of the prestalk cells. As this pacemaker reaches the upper surface of the slug it can initiate aerial migration.
盘基网柄菌蛞蝓在琼脂基质上迁移时，会在其黏液鞘痕迹中留下弯曲的印记。这些“足迹”是由蛞蝓前端在开始空中迁移阶段时的抬高所导致的，并且可以用作衡量蛞蝓这种行为倾向的指标。已发现多种因素会影响每迁移一段距离所产生的足迹数量。较小的蛞蝓比较大的蛞蝓产生足迹的发生率更高。在光照下迁移以及迁移过程中温度较低会增加足迹发生率。活性炭会降低足迹发生率，而外源添加氨则会增加足迹发生率。对土壤三维（3D）环境的模拟表明，空中迁移在蛞蝓在其自然环境的洞穴中移动时发挥作用。一个模型提出，空中迁移由一小群不断变化的前柄细胞启动，这些细胞充当起搏器，并通过前柄细胞的旋转在蛞蝓前端的圆周周围移动。当这个起搏器到达蛞蝓的上表面时，它就可以启动空中迁移。
