Interfaces in tissues are ubiquitous, both between tissue and environment as well as between populations of different Inline - Skates - JuniorIntermediate cell types.The propagation of an interface can be driven mechanically.Computer simulations of growing tissues are employed to study the stability of the interface between two tissues on a substrate.From a mechanical perspective, the dynamics and stability of this system is controlled mainly by four parameters of the respective tissues: (i) the homeostatic stress (ii) cell motility (iii) tissue viscosity and (iv) substrate friction.
For propagation driven by a difference in homeostatic stress, the interface is stable for tissues which differ in their substrate friction even for very large differences of homeostatic stress; however, it becomes unstable above a critical stress difference when the tissue with the larger homeostatic stress has a higher viscosity.A small difference in directed bulk motility between the two tissues suffices to result in propagation with a stable interface, even for otherwise identical tissues.Larger differences in motility force, however, result in a finite-wavelength instability of the interface.Interestingly, the instability is apparently bound by nonlinear effects and the amplitude of Grater the interface undulations only grows to a finite value in time.