Four dimensional analysis of vesicle dynamics during directed cell migration

The phenomenon of directed cell migration is one of many fundamental biological processes required for the existence of almost all living organisms. Efficient cell migration relies on a highly coordinated spatio-temporal system of sub-cellular processes, many of which are governed by transportation carriers known as vesicles. This thesis focuses on methods for analysing the dynamics of vesicles during directed cell migration via imaging and image analysis. Vesicle dynamics can be visualised in live cells by fluorescence microscopy. Different fluorescence microscopy techniques are better suited for studying different aspects of vesicle dynamics. First, the concept of multi-modality microscopy is explored, which combines the benefits of multiple methods into the same analyses. Thorough characterisation of vesicle dynamics requires accurately estimating thousands of trajectories from microscopy image sequences often consisting of hundreds or thousands of images. A highly efficient probabilistic multiple particle tracking frameworks is presented, which outperforms many of the state-of-the-art methods, but with a drastically reduced processing time. Finally, live cell studies show that there is a high degree of polarity of vesicle traffic of vesicles associated with the clathrin mediated endocytosis and early endosome pathways during cell migration