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dc.contributor.authorPoirier, Lucen
dc.date2008-12-22 17:13:42.089
dc.date.accessioned2009-01-08T19:46:41Z
dc.date.available2009-01-08T19:46:41Z
dc.date.issued2009-01-08T19:46:41Z
dc.identifier.urihttp://hdl.handle.net/1974/1649
dc.descriptionThesis (Ph.D, Biology) -- Queen's University, 2008-12-22 17:13:42.089en
dc.description.abstractTwo common strategies used to identify specific genes that influence aging in Drosophila melanogaster are overexpression screens and candidate gene approaches. Both of these strategies rely on gene expression systems. A very popular gene expression system in Drosophila is the bipartite UAS/GAL4 system, where binding of GAL4 to a UAS sequence can direct the expression of a UAS-linked transgene in a pattern determined by GAL4. Although the UAS/GAL4 system allows for spatial regulation of transgene expression, it does not allow researchers to control when transgene expression will occur. This is an important consideration since aging research is primarily interested in identifying genes that influence aging during adulthood, therefore requiring that transgene expression be effectively blocked during pre-adult stages. Both the Gene-Switch and the Tet-Off/GAL80 systems are attempts to establish temporal control over GAL4 activity. The Gene-Switch system is based on a modified form of GAL4 whose transcriptional activity can be controlled through the antiprogestin molecule RU486. The Tet-Off/GAL80 system, where expression of GAL80 (a negative regulator of GAL4) is under the control of a tetracycline sensitive expression system, allows regulation of GAL4 activity through the antibiotic tetracycline. Characterization of these systems reveals that although neither system can completely repress leaky transgene expression, the Tet-Off/GAL80 system is much better at preventing unwanted transgene expression at most stages of the fly life cycle. Furthermore, comparison of muscle specific GAL4 and Gene-Switch strains revealed that upon treatment with their respective inducers, the Tet-Off/GAL80 system allows for GAL4 activity in the muscles, while the Gene-Switch system results in GAL4 activity in other tissues in addition to the muscles. In other characterized Gene-Switch strains, GAL4 activity is achieved only in a subset of the cells of the targeted tissue, suggesting that the Gene-Switch system may be ill-suited for aging studies. These findings, along with the fact that the Tet-Off/GAL80 but not the Gene-Switch system is compatible with the hundreds of characterized GAL4 lines presently available which allows transgene expression to be targeted to most tissues, indicate that the Tet-Off/GAL80 system is the best-suited for aging studies in Drosophila at present.en
dc.format.extent196275548 bytes
dc.format.mimetypeapplication/pdf
dc.language.isoengen
dc.relation.ispartofseriesCanadian thesesen
dc.rightsThis publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.en
dc.subjectTet-Off/GAL80en
dc.subjectInducible expression in agingen
dc.subjectDrosophila melanogasteren
dc.subjectGene-Switch linesen
dc.titleInducible gene expression systems for aging studies in Drosophila melanogasteren
dc.typethesisen
dc.description.degreePhDen
dc.contributor.supervisorSeroude, Laurenten
dc.contributor.departmentBiologyen
dc.degree.grantorQueen's University at Kingstonen


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