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dc.contributor.authorHarry, Kathryn Heleneen_US
dc.date.accessioned2008-06-04en_US
dc.date.accessioned2014-03-14T21:35:41Z
dc.date.available2008-06-04en_US
dc.date.available2014-03-14T21:35:41Z
dc.date.issued2008-04-28en_US
dc.date.submitted2008-05-07en_US
dc.identifier.otheretd-05072008-115555en_US
dc.identifier.urihttp://hdl.handle.net/10919/42517
dc.description.abstractClostridium perfringens is a leading cause of food poisoning annually in the United States. Ingested C. perfringens vegetative cells respond to the acidic conditions of the stomach by initiating sporulation. The process of sporulation is essential in the formation of an enterotoxin (CPE) that is responsible for the symptoms of acute food poisoning. During sporulation, the cell must differentiate into the mother cell and the forespore. Studies in Bacillus subtilis have shown that gene expression during sporulation is compartmentalized, with different genes expressed in the mother cell and the forespore. The cell-specific RNA polymerase sigma factors coordinate the development of the differentiating cell. These sigma factors are Ï F, Ï E, Ï G, and Ï K. The C. perfringens cpe gene, encoding the enterotoxin CPE, is transcribed from three promoters, P1, P2, and P3. P2 and P3 were previously proposed to be Ï E-dependent, and P1 was proposed to be Ï K-dependent based on consensus recognition sequences. In this study, mutations were introduced into the sigE and sigK genes of C. perfringens. In the sigE and sigK mutants, promoter fusion assays indicated that there was no transcription of cpe in either mutant. We also determined through transcriptional analyses that Ï E-associated RNA polymerase and Ï K-associated RNA polymerase co-regulate the transcription of each other. RT-PCR analyses indicated that Ï K is a very early acting sigma factor. The evidence provided here shows that the regulation of sporulation in C. perfringens is not the same as it is in B. subtilis, as previously proposed.en_US
dc.publisherVirginia Techen_US
dc.relation.haspartHarryThesis.pdfen_US
dc.rightsI hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Virginia Tech or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.en_US
dc.subjectClostridium perfringensen_US
dc.subjectsporulationen_US
dc.subjectsigma factorsen_US
dc.subjectCPEen_US
dc.subjectfood poisoningen_US
dc.titleSporulation and enterotoxin regulation by sigma factors in Clostridium perfringensen_US
dc.typethesisen_US
dc.contributor.departmentBiologyen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
dc.contributor.committeechairMelville, Stephen B.en_US
dc.contributor.committeememberChen, Jiann-Shinen_US
dc.contributor.committeememberSchubot, Florian D.en_US
dc.contributor.committeememberYang, Zhaominen_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-05072008-115555/en_US


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