Molecular Biotechnology Programme
Uppsala University School of Engineering
UPTEC X 08 043 Date of issue 2008-11-11 Author
Mats Walldén
Title (English)
Synchrony in replication initiation
Title (Swedish) Abstract
Regulation of chromosomal replication initiation in Escherichia coli has been studied extensively.
Observations indicate that initiation occurs synchronously once every cell generation, in contrast to plasmids which initiate asynchronously independently of the cell cycle. In order to assess how a cyclic process such as initiation may be regulated a synchronous plasmid model, consisting of nonlinear ordinary differential equation, was devised. In this study the regulation and synchrony of initiation in this model is characterized in terms of the distribution of sensitivity to signals along the cycle. The model is also extended to include an additional regulatory circuit and the effects of doing so are
characterized in the light of the original model. The results indicate that synchronous initiation requires temporally distinct cycle coordinates and a sensitivity distribution that offers high sensitivity coinciding with the regulatory events. The extended model results in a loss of sensitivity. This loss however is rescued by additional factors that allow the system to be adequately regulated and initiate in synchrony.
The methods include a partial analytical treatment complemented by numerical integration in MATLAB.
Keywords
Replication Initiation, Synchrony, Copy Number Control
Supervisors
Måns Ehrenberg
Institute for Cell and Molecular Biology, Uppsala University
Scientific reviewer
Johan Elf
Institute for Cell and Molecular Biology, Uppsala University
Project name Sponsors
Language
English
Security
ISSN 1401-2138 Classification
Supplementary bibliographical information Pages 34
Biology Education Centre Biomedical Center Husargatan 3 Uppsala Box 592 S-75124 Uppsala Tel +46 (0)18 4710000 Fax +46 (0)18 555217
