<p> Leaf senescence is the final stage of leaf development where older leaves undergo an active degenerative process. This highly coordinated event is characterized by a cascade of differential gene expression resulting in senescence upregulated and senescence downregulated genes. Cytosine methylation, a mechanism of epigenetic control, has been shown to play a role in regulating gene expression. Gene body cytosine methylation is correlated with transcriptional activation while promoter cytosine methylation is correlated with transcriptional repression. Evidence from previous work suggests CG methylation (<sup>m</sup>CG) in promoter regions plays a role in repressing gene expression and that a correlation between demethylation and mRNA induction is most likely within 500 bp up- and downstream of TSSs. The purpose of this study is to investigate the correlation between promoter cytosine methylation and transcriptional repression by identifying potential cytosine methylation-regulated senescence upregulated genes (CMR-SURGs). Four candidate CMR-SURGs were identified from previously generated RNA-seq data and an online cytosine methylome. We hypothesized that the four CMR-SURGs would display a correlation between mRNA induction and loss of promoter <sup> m</sup>CG. mRNA expression was measured by real-time qPCR, and cytosine methylation was quantified by bisulfite treatment of genomic DNA followed by PCR, cloning, and sequencing of PCR products. These data however, showed that only <i>UGT78D1</i> displayed a negative correlation between promoter cytosine methylation and age-related mRNA induction.</p><p>
| Identifer | oai:union.ndltd.org:PROQUEST/oai:pqdtoai.proquest.com:10600929 |
| Date | 04 October 2017 |
| Creators | To, Kevin S. |
| Publisher | California State University, Long Beach |
| Source Sets | ProQuest.com |
| Language | English |
| Detected Language | English |
| Type | thesis |
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