Anticipation of periodic events influences cell motility in amoeba proteus.

All migrating cells (both single-cell organisms and as part of multicellular organisms) sense environmental conditions and respond to physical and molecular cues by changing the direction and speed of cellular movement. Adaptive behaviors enable motile cells to thrive in dynamic environments. A study with slime mold suggested an ability to anticipate dry and cold periods. However, experimental evidence for anticipation in other single-cell organisms is lacking. Here, we investigated whether Amoeba proteus can anticipate unfavourable periodic stimuli. Amoeba proteus react to blue light (405 nm) by reducing their streaming speed in response to each stimulation. As expected, after four periodic blue light stimulations A. proteus presented spontaneous in-phase reduction in streaming speed at the time point when the next stimulation would have occurred. Our results corroborate the claim that single cells are able to anticipate periodic environmental cues and change their behaviour in anticipation of these cues. These findings may have implications for the interpretation of cellular processes in vitro and in vivo even in complex multicellular systems.