Signaling Delays Preclude Defects in Lateral Inhibition Patterning

Developmental biology is extraordinarily robust in its ability to self-organize exquisite spatio-temporal patterns despite an intrinsically noisy set of parts. Lateral inhibition is one mechanism commonly implicated in the formation of such precise emergent behavior. Models of lateral inhibition's patterning capabilities usually implicitly assume, however, that cells receive expression signals from their neighbors without delay. Here we explicitly investigate the effects of signaling delays as well as their relation to cis-interactions in lateral inhibition patterning. We find that rather than being a source of error, signaling delays counter-intuitively allow biology to ensure defect-free patterning, which together with cis-interactions can be both fast and robust to noise and parameter variation. This suggests that overlooking time delays in developmental signaling does not just ignore a potential source of error, but rather ignores a knob with which evolution may tune patterning robustness in general.