In vivo anomalous diffusion and weak ergodicity breaking of lipid granules

TL;DR

This study combines microscopy data and analytical models to reveal that lipid granules in living yeast cells exhibit anomalous diffusion, including subdiffusion and fractional Brownian motion, with weak ergodicity breaking at short times.

Contribution

It provides experimental evidence and analytical characterization of anomalous diffusion and weak ergodicity breaking in lipid granules within living cells.

Findings

Granules show subdiffusion at short times consistent with continuous time random walk theory.

Weak ergodicity breaking causes a turnover between two scaling regimes.

At longer times, granule motion aligns with fractional Brownian motion.

Abstract

Combining extensive single particle tracking microscopy data of endogenous lipid granules in living fission yeast cells with analytical results we show evidence for anomalous diffusion and weak ergodicity breaking. Namely we demonstrate that at short times the granules perform subdiffusion according to the laws of continuous time random walk theory. The associated violation of ergodicity leads to a characteristic turnover between two scaling regimes of the time averaged mean squared displacement. At longer times the granule motion is consistent with fractional Brownian motion.