The Microsoft Research - University of Trento Centre seminar
Tue Sep 27, 2011 at 15:00
Meeting room A Piazza Manci, 17, Povo
Andre Sances Ribeiro
Recent evidence suggests that most RNA molecules exist in low copy numbers in Escherichia coli, since most genes are expressed one to a few times during the cell’s lifetime. Cellular phenotype relies not only on the mean numbers of these molecules, but also on the timing of production and the degree of fluctuations. Given their small numbers, small fluctuations in RNA levels likely have downstream effects on the phenotype. Bacteria may therefore have evolved mechanisms to stringently control stochasticity in the expression of some genes. We describe recent studies of the dynamics of a model of gene expression at the nucleotide and codon levels and characterize the role of transcription initiation and elongation kinetics on the dynamics of RNA and protein numbers. We also analyze, using the model, possible strategies for reducing stochasticity in these numbers. Finally, we report temporal measurements of mRNA production at the molecule level under the control of the lar promoter. From these, we characterize the underlying in vivo dynamics of transcription initiation and show evidence of a two rate-limiting steps mechanism limiting fluctuations in RNA numbers.
About the speaker
Andre Sances Ribeiro is Assist Professor, Computational Systems Biology Research Group, at Department of Signal Processing, Tampere University of Technology - Finland (http://www.cs.tut.fi/~sanchesr/).
Contact: Corrado Priami