An experimental investigation into the mechanisms of bacterial evolution

<p>This thesis studies the two fundamental mechanisms of bacterial evolution &mdash; horizontal gene transfer and spontaneous mutation, in the bacterium <em>Escherichia coli</em> through novel experimental assays and mathematical simulations. First, I will develop a growth assay utilizing the quantitative polymerase chain reaction (qPCR) to provide real-time enumeration of genetic marker abundance within bacterial populations. Second, I will focus on horizontal gene transfer in <em>E. coli</em> occurring through a process called conjugation. By fitting the qPCR data to a resource limited, logistic growth model, I will obtain estimated values of several key parameters governing the dynamics of DNA transfer through conjugation under two different conditions: i) in the absence of selection; ii) in the presence of negative selection pressure &mdash; bacteriophage infection. Last, I will investigate spontaneous mutation through qPCR assay of competition between wild-type and mutator phenotype <em>E. coli</em>. Mutator phenotype has an elevated mutation rate due to defects in DNA proofreading and repairing system. By introducing antibiotic selective pressure, I will examine the fixation probability of mutators competing with wild-type in novel environment. I also will utilize simulations to study the impact of three parameters on the fixation probability. </p>

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Physics

Grantor

The Graduate School and University Center of The City University of New York

Year dc:date.available

2014

Author dc:creator

• Wan, Zhenmao

Advisor dc:contributor.advisor

• Mark Hillery

• Biology
• Biophysics
• Physics
• Bacterial Evolution
• Horizontal Gene Transfer
• Population Dynamics
• Spontaneous Mutation

Repository record dc:identifier

https://academicworks.cuny.edu/gc_etds/125

OAI identifier oai:identifier

oai:academicworks.cuny.edu:gc_etds-1124