Theses and Dissertations - UTB/UTPA

Date of Award


Document Type


Degree Name

Master of Science (MS)



First Advisor

Dr. Erin Schuenzel

Second Advisor

Dr. Robert Dearth

Third Advisor

Dr. Matthew Terry


The relationship between a pathogen and its host is a constant interaction; as the host evolves defense mechanisms to protect itself from the pathogen, the pathogen will evolve in order to evade them. During this evolutionary process, the genomes of bacterial pathogens can change due to different selection pressures exerted by the immune system of their respective hosts. This study aimed to determine how differences in selection pressures affect the evolution of plant and vertebrate pathogens. The focus of this study was to analyze population level changes in conserved genes, as well as species level changes in the Type III Secretion System (T3SS) and in conserved genes of various pathogens. Results suggest that, at the population level, a difference in the life history of plant and vertebrate pathogens exists. At the species level, various genes are seemingly undergoing differential and/or positive selection regardless of the host.


Copyright 2014 Alejandro Cantu. All Rights Reserved.

Granting Institution

University of Texas-Pan American