#5 · Systems biology

Adhesion, noise, and discretization shape collective and single-cell migration models

The common thread is minimal mechanical and stochastic modeling of individual cell behavior and its propagation to collective outcomes. A non-local advection-diffusion model of leader-follower migration finds that adhesion limits follower cohort size to the interaction lengthscale, well short of extended streams. A finite Voronoi model for nonconfluent tissues shows diverging detachment forces and time-step-dependent fracture artifacts. Stochastic simulation of individual Rho GTPase molecules indicates that intrinsic polarity noise from finite copy number can mask contact inhibition of locomotion. Phase-field modeling of Drosophila border cell cluster migration introduces a Tangential Interface Migration force driven by nurse cell contact. The new element is explicit tracing of molecular noise, numerical discretization, and rule-based exclusion to tissue-scale outcomes, though the items vary in system and scope, and the proliferation study addresses volume exclusion and cell cycle staging rather than migration.