CoSy lunch seminar 28/01/2020

Abstract: A number of recent studies have shown that natural selection occurs not only on genes (on genetic variation), but also at the level of gene expression (on heritable phenotypic variation). Emergent gene expression can be defined as the selective upregulation of a fitness conferring gene when a cell population is placed in a stressful environment.  One of the clearest example of this phenomena is concerning the expression of the HisC gene in E. Coli after cells are placed in a histidine deprived environment. The HisC enzyme plays a crucial role in the synthesis of Histidine, an essential amino acid required for cell growth.   In this talk, I will present a minimal mathematical model of HisC expression that links stochastic gene expression to cell growth and partitioning/dilution. I will then go on to present the minimal ingredients required for emergent gene expression to take place. I will end by changing contexts and present a similar model of MGMT expression in glioblastoma cells which may explain a possible mechanism by which chemotherapy resistance can develop in the absence of genetic mutations.