Macroscopic current generated by local division and apoptosis in a minimal model of tissue dynamics.

It has been known that the motion of self-propelled particles inside an asymmetric channel can be rectified to give rise to a macroscopic and unidirectional current. In this paper, we show that division and apoptosis process alone (which are ubiquitous in all living systems), without any self-propulsion, are sufficient to give rise to a macroscopic and unidirectional current in a similar channel. More specifically, we consider a minimal computational model of two-dimensional living tissues, with two active ingredients: local particle division and apoptosis, and we found a net steady state current along the channel. This mechanism is fundamentally different from that of self-propelled particles, since this requires the system to be dense. Finally, our results might have applications in tissue engineering such as controlling tissue growth via a geometrically non-uniform substrate.