Influence of spatial resolution and single cell identification on bacteria cell cycle observations

Abstract

Accurate description of bacterial dynamics is an important factor for understanding the bacterial cell cycle. Traditionally direct observation of cell cycle dynamics using light microscopy has been restricted by the diraction limit. In recent years a number of super-resolution techniques have been developed allowing to overcome these limitations. However, time-lapse imaging of single cells is challenging due to photobleaching from prolonged illumination and cell movement between images. In addition, some dyes used in these techniques require the bacteria to be fxed prior to microscopy. This thesis explores the possibilities to reconstruct a pseudo-temporal trajectory from static images of cell populations and compares them to lower resolution single cell time lapse microscopy. Results indicate that pseudo-temporal reconstruction can provide a good approximation of the average development trajectories provided a suffcient number of cells in each cell cycle phase is available for analysis.