BPS2026 – From mazes to mingling: Transport and mixing in active mitochondrial networks

Mitochondria form a variety of dynamic architectures that range from physically interconnected networks of tubules to loosely associated populations of individual organelles that interact only transiently. These distinct structural states are thought to play a key functional role by controlling the mixing and homogenization of the mitochondrial population. We present a physical modeling framework to explore how network morphology, fusion-fission dynamics, and mitochondrial transport combine to define the rate of dispersion for mitochondrial material. Using simulations and analytic approximations, we identify the key parameter combinations that determine spreading rates in dynamic network morphologies. Network regimes relevant to distinct cell types will be discussed, including near-percolated networks in mammalian cells and actively transported mitochondria that merge into broadly distributed clusters in the dendritic trees of Drosophila sensory neurons. Integrating model predictions with live-cell imaging data from collaborating groups, our work highlights how the interplay of structure, dynamics, and transport, shapes mitochondrial heterogeneity in diverse cellular systems.