Temporal ordering of migration increments carries directional memory under MYO10 depletion and collagen exposure

Abstract

A cell track contains not only a set of movements but also an order. We asked whether that order reveals behaviour that speed, endpoint displacement, and conventional persistence measures miss. For each trajectory, we compared the recorded sequence with an exact reference in which the same displacement steps were rearranged; the observed-minus-reference difference quantifies persistence created by step order. In 48,134 MCF10DCIS.com trajectories, most of a reproducible MYO10-collagen interaction in directional persistence disappeared when temporal order was removed. In 131 single MCF10A haptotaxis tracks, widening the fibronectin pattern did not produce a resolved global increase in order; it shifted short- timescale organization from the gradient axis toward lateral movement, with an intrinsic lateral-order difference of 0.2176 (95% hierarchical interval 0.1274-0.3171). In MDA-MB-231 cells migrating toward EGF, PFKL-N702T produced fewer up-gradient steps and shorter up-gradient runs while the mean-speed difference remained unresolved. These directional effects remained after comparisons balanced for measured speed and duration, whereas three cue-independent serial-order measures showed no reduction larger than a locked 0.10-SD margin at the track level. Across independent endothelial, epithelial, and cancer-cell archives, the same calculation distinguished sustained, short-lived, and sign-reversing regimes; a stationary angular hidden-state model failed all eight frozen long-lag targets. Temporal order therefore separates three biological questions: how much a cell moves, whether it continues moving persistently, and whether that persistence remains aligned with an environmental cue. We provide a documented workflow that calculates these readouts from standard x-y tracking tables. Impact statementThe order of otherwise similar migration steps reveals whether cells merely continue moving or sustain commitment to an environmental cue.