Mitochondria are organelles that participate in many cellular processes. They also have the ability to dynamically change their shape, size and distribution according to the cell state. We analyze confocal microscopy images of mitochondria in Xenopus laevis melanophore living cells to explore different mechanical and morphological properties at the single-organelle level. We combine this experimental approach with theoretical modeling and numeric simulations to gain a deeper understanding of the underlying mechanisms.

First, we developed a 1D numerical model for the intracellular transport of flexible and elongated organelles like mitochondria. This work provided valuable insights into how unbalanced forces from different motor teams lead to deformations in transported organelles.

Then, we focused on understanding how the cytoskeleton dynamics and motor forces impact on mitochondrial morphology and organization. We performed several cell treatments that selectively affect different cytoskeletal  networks (microtubules, F-actin and vimentin filaments). These experiments allowed us to estimate, for the first time, the apparent persistence length of mitochondria, revealing that microtubules and F-actin have dual effects on these organelles’ shape fluctuations and mechanics.

Building on this, our more recent work consists of simulating the behavior of a filamentous mitochondrion using a worm-like chain model in a viscous medium with thermal noise. External forces were applied randomly along the filament to study how they influence the organelle's shape. Preliminary results suggest that active forces are necessary for the mitochondria to mimic the behaviors seen in living cells