GBCB Seminar (Genetics, Bioinformatics & Computational Biology)
Speaker: Shenghua Li, PhD candidate in GBCB
Advisor: Dr. John Tyson, Biology Dept at VT
Title: Quantitative Modeling of the Asymmetric Cell Division Cycle in Caulobacter crescentus
Abstract: Caulobacter crescentus is an important model organism for studying the regulation of cell growth and division and cellular differentiation in prokaryotes. Caulobacter undergoes asymmetric division producing two progeny cells with identical genome but different developmental programs: the "swarmer" cell is flagellated and motile, and the "stalked" cell is sessile (attached to a surface by its stalk and holdfast). Only stalked cells undergo chromosome replication and cell division. A swarmer cells must shed its flagellum and grow a stalk before it can enter the replication-division cycle. Based on published experimental evidence, we propose a molecular mechanism for cell cycle control in this bacterium. Our quantitative model predicts detailed temporal dynamics of regulatory gene expression during the cell cycle and differentiation process of wild-type cells (both stalked cells and swarmer cells) as well as several mutant strains. Our model presents a unified view of temporal and spatial regulation of protein activities during the asymmetric cell division cycle of Caulobacter. It helps to interpret phenotypes of known mutants and predict novel ones. The model can serve as a starting point for investigating the regulation of cell division and differentiation in other genera of alpha-proteobacteria, such as Brucella and Rhizobium, because recent experimental data suggest that these alpha-proteobacteria share similar genetic mechanisms for cell cycle control.
Ausmees, N., and Jacobs-Wagner, C. (2003). Spatial and temporal control of differentiation and cell cycle progression in Caulobacter crescentus. AnnuRevMicrobiol 57, 225-247....Good Review on molecular biology of Caulobacter.
Brazhnik, P., and Tyson, J.J. (2006). Cell cycle control in bacteria and yeast: a case of convergent evolution? Cell Cycle 5, 522-529...Core mechanism proposed for cell division cycle control in Caulobacter.
Sible, J.C., and Tyson, J.J. (2007). Mathematical modeling as a tool for investigating cell cycle control networks. Methods 41, 238-247...Good review on mathematical methods used for quantitative modeling of cellular dynamics.
Seminar is open to the public, all are welcome to attend.
Light refreshments before seminar from 3:15-3:55; seminar starts promptly at 4pm and lasts until 5pm.