Electrical engineering

Physics

Cytoskeleton

Cell

Neuroscience

Biological system

Cell polarity

Biology

Gene

Centrosome

Biophysics

Engineering

Coupling (piping)

Voltage

Pattern formation

Metallurgy

Materials science

Programming language

Cell cortex

Polarity (international relations)

Cell cycle

Computer science

Quantum mechanics

Positive feedback

Genetics

Biochemistry

Robustness (evolution)

Negative feedback

Turing

Nature Physics

Spontaneous pattern formation in Turing systems relies on feedback. But patterns in cells and tissues seldom form spontaneously—instead they are controlled by regulatory biochemical interactions that provide molecular guiding cues. The relationship between these guiding cues and feedback in controlled biological pattern formation remains unclear. Here, we explore this relationship during cell-polarity establishment in the one-cell-stage Caenorhabditis elegans embryo. We quantify the strength of two feedback systems that operate during polarity establishment: feedback between polarity proteins and the actomyosin cortex, and mutual antagonism among polarity proteins. We characterize how these feedback systems are modulated by guiding cues from the centrosome, an organelle regulating cell cycle progression. By coupling a mass-conserved Turing-like reaction–diffusion system for polarity proteins to an active-gel description of the actomyosin cortex, we reveal a transition point beyond which feedback ensures self-organized polarization, even when cues are removed. Notably, the system switches from a guide-dominated to a feedback-dominated regime well beyond this transition point, which ensures robustness. Together, these results reveal a general criterion for controlling biological pattern-forming systems: feedback remains subcritical to avoid unstable behaviour, and molecular guiding cues drive the system beyond a transition point for pattern formation. A study of how single C. elegans cells establish the polarity required for cell division reveals a general principle for pattern formation in living systems controlled by biochemical cues.

Guiding self-organized pattern formation in cell polarity establishment