Cellular Biophysics - Transport

Cellular Biophysics, Transport [131149]

  Dr. Matthew Daddysman, Dr. Toan Huynh 

How do objects move inside cells? What is the correct statistical description of this transport? How is transport in complex environments affected by the metabolic state of the cell and cell stimulation? Are the mechanisms of transport designed by evolution to do more than just get "stuff" from here to there and if so are cells optimized for robustness or other qualities? We are studying the dynamics of insulin-containing granule transport in beta cells, clusters thereof and in islets of Langerhans with a longer view to whether the diabetic disease phenotype is related to transport. We have found a new statistics, which combines continuous time random walks with fractional Brownian motion, that describes the granule (vesicle) transport in these cells. We are extending these single granule particle tracking measurements to the dynamics of microtubules in vivo. This is a challenging issue from both the image analysis/tracking perspective and also establishing the correct mechanical description of their string-like motion. As for the bacterial system, we apply chemical and optogenetic perturbations to the cells to change the cell state to understand how transport, as a nonequilibrium process, is altered.

(left) EGFP-labeled granules in a MIN6 cell (image size ~30x20μm) and (right) trajectories of granule motions from 300 frames in a movie.