Publication Date


Document Type


First Advisor

Hill, Stuart A.

Degree Name

B.S. (Bachelor of Science)

Legacy Department

Department of Biological Sciences


The role of the RecBCD recombination pathway in PilE variation in Neisseria gonorrhoeae is debatable and dependent on the strain studied. In the MSI 1 strain, recB mutants were assessed for recombination/repair by assessing their ability to repair double-chain breaks. The MSI 1 recB mutants were found to be highly susceptible to these DNA double-chain break treatments and were severely impaired for growth; recB growth suppressor mutants arose at high frequencies. When the recombination/repair capacity of MSI 1 were compared to other strains (FA1090 and P9), innate difference were observed between each as FA1090 and P9 rec bacteria had pronounced recombination/repair defects. Moreover, MSI 1 recB mutants present a more robust phenotype than the other strains. Additionally, MSI 1 recB mutants are also shown to be defective for pilE/pilS recombination. pilE/pilS recombination is also shown to proceed with gonococci that carry an inverted pilE locus. From this study, an innovative RecBCD-mediated double-chain-break repair model for PilE antigenic variation is proposed.


Includes bibliographical references.


29 unnumbered pages




Northern Illinois University

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