PhD defence H.P. (Heta) Patel

Summary:

Cells are the basic unit of life and all the information required to build and maintain a cell is contained in its genetic material, DNA. The process of converting information from segments of DNA (genes) to proteins is called gene expression. Cells can modulate all steps of gene expression to precisely control when proteins are made and how many proteins are made, but the timing and magnitude of protein production can vary between genetically identical cells in the same environment. The heterogeneity is due to stochastic gene expression, in which genes can randomly switch between active and inactive states. Therefore, at any time, a gene will be active in one cell but inactive in another. This heterogeneity in gene expression, which allows cells to adapt, survive and evolve in everchanging environments, has been observed in living cells across all kingdoms of life. However, because the inner workings of a cell are incredibly dynamic, it is difficult to study and understand the nanoscale interactions of biological molecules that leads to the orchestrated activation and expression of specific genes. In this thesis, we use single-cell and single-molecule microscopy approaches in living cells to understand what drives heterogeneity in gene expression.