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dc.contributor.advisorBonham-Smith, Peta C.en_US
dc.creatorMcIntosh, Kerri Brynen_US
dc.date.accessioned2005-11-22T13:58:48Zen_US
dc.date.accessioned2013-01-04T05:09:01Z
dc.date.available2006-11-24T08:00:00Zen_US
dc.date.available2013-01-04T05:09:01Z
dc.date.created2005-11en_US
dc.date.issued2005-11-09en_US
dc.date.submittedNovember 2005en_US
dc.identifier.urihttp://hdl.handle.net/10388/etd-11222005-135848en_US
dc.description.abstractRPL23a is one of the ~80 ribosomal proteins (r-proteins) of the cytoplasmic ribosome in the model plant Arabidopsis thaliana. The objectives of this research were to establish Arabidopsis RPL23a as a functional r-protein, characterize expression patterns for the two genes (RPL23aA and B) encoding RPL23a using reverse transcription PCR (RT-PCR), and identify regulatory elements controlling the expression of RPL23aA and B. Complementation of a yeast l25 mutant with AtRPL23aA demonstrated that AtRPL23aA can fulfill all the essential functions of L25 in vivo. A survey of various Arabidopsis tissue types showed that, while RPL23aA and B expression patterns both showed increased transcript abundance in mitotically active tissues, RPL23aB transcript levels were generally lower than those of RPL23aA and responded differently to abiotic stresses. In order to determine cis regulatory elements controlling RPL23aA and B expression, the 5’ regulatory region (RR) of each gene was characterized via plants carrying a series of 5’ RR deletion fragments upstream of a reporter. Transcript start sites and 5’ untranslated regions (UTRs) for both RPL23aA and B were also characterized using primer extension, and transcripts from 5’ deletion transgenics were amplified using RT-PCR. No correlation was observed between putative cis-acting elements and the expression patterns from the RPL23aA and B deletion transgenics, although a 102 bp sequence in the RPL23aB 5’ RR was found to contain pollen-specific elements. 5’ leader introns were found in each RPL23a gene, and amplification of transgene transcripts from deletion series plants indicated the importance of post-transcriptional and translational regulation in RPL23aA and B expression. This thesis work is the first demonstration of a plant RPL23a protein as a functional member of the L23/L25 (L23p) conserved r-protein family, and is one of the few in-depth studies of the regulation of r-protein genes in plants. While the majority of previous research on plant r-protein gene expression has focused solely on transcript levels, I show herein that post-transcriptional mechanisms have a critical role in regulating these genes, and thus plant r-protein genes more strongly resemble their mammalian counterparts than those of yeast in terms of structure and regulation.en_US
dc.language.isoen_USen_US
dc.subjectregulatory regionen_US
dc.subjectyeast complemetationen_US
dc.subjectribosomeen_US
dc.subjectribosomal proteinen_US
dc.subjectArabidopsisen_US
dc.subjectgene expressionen_US
dc.titleCharacterization of the two genes encoding cytoplasmic ribosomal protein L23a in Arabidopsis thalianaen_US
thesis.degree.departmentBiologyen_US
thesis.degree.disciplineBiologyen_US
thesis.degree.grantorUniversity of Saskatchewanen_US
thesis.degree.levelDoctoralen_US
thesis.degree.nameDoctor of Philosophy (Ph.D.)en_US
dc.type.materialtexten_US
dc.type.genreThesisen_US
dc.contributor.committeeMemberRoesler, William J.en_US
dc.contributor.committeeMemberMessier, Françoisen_US
dc.contributor.committeeMemberKaminskyj, Susan G. W.en_US
dc.contributor.committeeMemberDavis, Arthur R.en_US
dc.contributor.committeeMemberBailey-Serres, Juliaen_US


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