Long-term cellular cargo tracking reveals intricate trafficking through active cytoskeletal networks

Abstract

A eukaryotic cell is a microscopic world within which efficient material transport is essential. To examine cargo transport in a crowded cellular environment, we tracked unlabeled cargos in directional motion in a massively parallel fashion using the interferometric scattering microscopy. Our label-free, cargo-tracing method revealed not only dynamic cargo transportation but also the fine architecture of the actively used cytoskeletal highways and the long-term evolution of the associated traffic at sub-diffraction resolution via a myriad of molecular strokes. Cargos experience a traffic jam, but they have an effective strategy to circumvent it: moving together in tandem or migrating collectively. All taken together, a cell is an incredibly complex and busy space where the principle and practice in transportation intriguingly parallel those of our macroscopic world.