This thesis focuses on the analysis of the role of adhesion between substrate and cell and factors of Quorum sensing on the migration of Dictyostelium amoeba. Tools to automate the recordings of videomicroscopy and image analysis have been developed to work with very large samples of cells and toquantify cell migration. A microfluidic device for cell detachment in hydrodynamic flow combined witha motorized stage has allowed a statistical study of adhesion but also the dynamics of detachment. The analysis of the migration of Dictyostelium in non nutritive medium highlights the role of density on celldifferentiation and migration capacity. We observe the presence of a maximum speed of migration after6 hours of starvation. We show that the adhesion to glass is twice as low in deprivation buffer as inthe nutrient medium. The experiences of migration in growth medium revealed the presence of a factorof detection of density secreted by the cells and regulating their random migration. The diffusion coefficient, the persistence of the movement and morphology of cells vary depending on the concentrationof this factor. This factor does not affect cell adhesion but only the dynamics of detachment. Finally, the testing protocol developed allowed us to make a comparative study of migration by varying otherparameters such as surface or the chemical composition of experimental medium. This work concludesby outlining the possible role of adhesion to the migration of Dictyostelium in nutrient medium.
| Identifer | oai:union.ndltd.org:CCSD/oai:tel.archives-ouvertes.fr:tel-00846586 |
| Date | 09 December 2011 |
| Creators | Golé, Laurent |
| Publisher | Université Claude Bernard - Lyon I |
| Source Sets | CCSD theses-EN-ligne, France |
| Language | French |
| Detected Language | English |
| Type | PhD thesis |
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