Jenny Wachter

Publication Date


Document Type


First Advisor

Hill, Stuart A.

Degree Name

Ph.D. (Doctor of Philosophy)

Legacy Department

Department of Biological Sciences


Neisseria gonorrhoeae--Molecular aspects; Diseases--Molecular aspects; Molecular genetics


Piliation is an essential virulence factor for the obligate human pathogen Neisseria gonorrhoeae. PilE polypeptide is the major protein subunit in the pilus organelle and engages in extensive antigenic variation due to recombination between pilE and a pilS locus. pilS were so-named as they are believed to be transcriptionally silent, in contrast to the pilE locus. Despite the importance of pilE in pathogenesis, little is known regarding its regulation. Therefore, through small transcriptome analysis, we have identified a trans-encoded sRNA that was demonstrated to up-regulate expression of pilE. Furthermore, through small transcriptome analysis, in conjunction with analysis of pilS recombinants, we have identified both sense and antisense RNAs originating from most, but not all, of the pilS gene copies. Focusing on a single locus, we identified by site-directed mutagenesis a sense and antisense promoter. Analysis of available whole transcriptomes also revealed the presence of pilS-specific sRNAs in other pathogenic Neisseria. However, despite the presence of non-canonical promoter elements, investigation of available pil gene sequences revealed the presence of strong selection pressures, which provide support for host immune system pressure driving sequence polymorphisms within these variable genes. Overall, this study reveals an added layer of complexity to the pilE virulence gene.


Advisors: Stuart A. Hill.||Committee members: Rangaswamy Meganathan; Wesley Swingley; Yanbin Yin; Shengde Zhou.||Includes bibliographical references.||Includes illustrations.


viii, 219 pages




Northern Illinois University

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