Quantitative biology is an emerging field that attracts intensive research interests.
Pattern formation is a widely studied topic both in biology and physics.
Scientists have been trying to figure out the basic principles behind the fascinating
patterns in the nature. It’s still difficult to lift the complex veil on the
underling mechanisms, especially in biology, although lots of the achievements
have been achieved. The new developments in synthetic biology provide a different
approach to study the natural systems, test the theories, and develop
new ones. Biological systems have many unique features different from physics
and chemistry, such as growth and active movement. In this project, a link
between cell density and cell motility is established through cell-cell signaling.
The genetic engineered Escherichia coli cell regulates its motility by sensing
the local cell density. The regulation of cell motility by cell density leads to
sequential and periodical stripe patterns when the cells grow and expand on a
semi-solid agar plate. This synthetic stripe pattern formation system is quantitative
studied by quantitative measurements, mathematical modeling and
theoretical analysis.
To characterize the stripe pattern, two novel methods have been developed
to quantify the key parameters, including cell growth, spatiotemporal cell density
profile and cell density-dependent motility, besides the standard molecular
biological measurements.
To better understand the underlying principle of the stripe pattern formation,
a quantitative model is developed based on the experiments. The detailed
dynamic process is studied by computer simulation. Besides, the model predicts
that the number of stripes can be tuned by varying the parameters in
the system. This has been tested by quantitatively modulation of the basal
expression level of a single gene in the genetic circuit.
Moreover, theoretical analysis of a simplified model provides us a clear picture
of the stripe formation process. The steady state traveling wave solution
is obtained, which leads to an analytic ansatz that can determine the phase
boundary between the stripe and the no-stripe phases.
This study does not only provide a quantitative understanding about the
novel mechanism of stripe pattern formation, but also sets an good example
of quantitative studies in biology. The techniques, methods and knowledge
gleaned here may be applied in various interdisciplinary fields. / published_or_final_version / Physics / Doctoral / Doctor of Philosophy
| Identifer | oai:union.ndltd.org:HKU/oai:hub.hku.hk:10722/167218 |
| Date | January 2012 |
| Creators | Fu, Xiongfei., 傅雄飞. |
| Contributors | Zhang, F, Huang, J |
| Publisher | The University of Hong Kong (Pokfulam, Hong Kong) |
| Source Sets | Hong Kong University Theses |
| Language | English |
| Detected Language | English |
| Type | PG_Thesis |
| Source | http://hub.hku.hk/bib/B48199424 |
| Rights | The author retains all proprietary rights, (such as patent rights) and the right to use in future works., Creative Commons: Attribution 3.0 Hong Kong License |
| Relation | HKU Theses Online (HKUTO) |
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