Summer 2008 Research Experience: I conducted research during the summer of 2008 in the laboratory of Dr. Tai-Pin Sung, Biology Dept., Duke University, Durham, NC.
Research title: Effects of Light and Diurnal Cycles on the Protein Levels of Endogenous RGA and RGA-LUC.
Abstract: Gibberellins (GA) play a major role in all stages of plant development. DELLA proteins are key repressors of GA signaling. Some of the earliest steps in GA signaling have been recently elucidated after identification of GID1 as the GA receptor. GID1 and DELLA-proteins form a complex in a GA-dependent manner. Formation of this complex facilitates interaction with the F-box protein SLY1 which targets DELLA proteins for degradation through the SCFSLY1-26S proteasome pathway. Disappearance of DELLA proteins induces all aspects of vegetative growth and development. Interestingly, during early seedling development, light, and GA play antagonistic roles. This is especially evident in the regulation of hypocotyl growth, where GA promotes hypocotyl elongation by inducing DELLA protein degradation and light induces phytochromes that restrict hypocotyl growth. The transcription factors PIFs are known to promote hypocotyl growth and are rapidly degraded when phytochromes are activated. Recent studies have shown that DELLA proteins inhibit PIFs by blocking their DNA binding domains. Since PIFs are controlled by circadian rhythms and light, we decided to test if DELLA proteins were also subject to similar regulation. We used the bioluminescence of a DELLA-luciferase (RGA-LUC) fusion protein and Western blot analyses to monitor the levels of endogenous RGA and RGA-LUC proteins in seedlings subjected to different light and dark regimes. Monitoring bioluminescence of the fusion protein revealed that internal rhythms and photoperception may both play a role in regulating the abundance of DELLA proteins. These results are partially supported by our Western blot analyses.
Learn more about this project here.
Previous Research Experience: I conducted research under the Summer Undergraduate Research Experience, SURE, at Winston Salem State University during the summer of 2007 with Dr. Brian K. Nordskog.
Research title: The Effect of a Ketogenic Diet on T-Type Calcium Channel Gene Expression in a Mouse Model of Ethanol Withdrawal.
Abstract: Low threshold (T-type) calcium channels participate in the generation of normal brain rhythms as well as abnormal rhythms associated with a range of neurological disorders including seizures associated with epilepsy and alcohol withdrawal. A high fat diet, also known as a ketogenic diet, has been developed to treat epileptic seizures in humans that do not respond to common pharmacological treatments. In this study, we investigated whether the ketogenic diet would prevent seizures in an animal model of alcohol withdrawal. Our approach included feeding six-week old male C57BI/6 mice a ketogenic diet continuously prior to and during nine rounds of ethanol exposure and withdrawal. Each round consisted of exposing mice to ethanol vapor for 16 hours followed by 8-hour ethanol withdrawal period. On the last day, mice were euthanized during the seventh hour of withdrawal. This time period corresponds to maximum handling-induced seizures reported in literature. Two brain areas (thalamus and cortex) involved in seizure generation were isolated. Total RNA was prepared from these tissues for T-type calcium channel gene expression analysis. Real time RTPCR was used to determine differences in T-Type calcium genes in either the thalamus or the cortex in mice fed a ketogenic diet or a normal chow diet. Thus, it is unlikely that the ketogenic diet will prevent seizures that occur during alcohol withdrawal.