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Epigenetics Of Stress Adaptation In Arabidopsis: The Case Of Histone Modifications, Behnaz Najafi Majdabadi Farahani

Electronic Thesis and Dissertation Repository

Changes in the epigenetic status of plants, which contribute to changes in gene expression, in response to abiotic stress are well documented. However, their stability and transmission to subsequent generations, and their incorporation into plant stress adaptation are still a matter for debate. Using chromatin immuno-precipitation and Next Generation Sequencing (ChIP-seq), we compared genome wide enrichment of two histone marks, H3K9ac and H3K4me2, in the progeny of salt stressed and control Arabidopsis plants. Data showed less enrichment of the H3K9ac in the chromatin of the progeny of salt stressed plants, but no changes were detected in the enrichment of the …

The Effect Of Glycan Linked To Cationic Peanut Peroxidase On Its Activity, Maha M. Al-Subaie

Electronic Thesis and Dissertation Repository

The roles of heme-, calcium- and glycan moieties on the peanut peroxidase enzyme activity have been previously studied. While the 3-D protein structure is known and some information about the glycan chain is known, due to uneven distribution of the 5 glycans, only a partial understanding of the furthest sugar groups on the 16 glycan chain was available. Now, having used gel-filtration column chromatography followed by lectin affinity column work, I showed that there is a rich array of galactose there. Moreover, I determined that not too many of the sugars are removed in the culture period of 14 days. …

Exploring The Neural Basis Of Top-Down Guided Action In Macaque Monkeys, Jessica M. Phillips

Electronic Thesis and Dissertation Repository

To thoroughly characterize any brain mechanism requires an appropriate animal model for invasive studies. An invaluable model system used toward a comprehension of cognitive neurophysiology is the macaque monkey. It is important to delineate similarities and limitations for this model in relation to the human brain and cognition. In this thesis, we have thus conducted three experiments to investigate putative generalizations between monkeys and humans regarding the neural processes associated with top-down action control in monkeys.

Our daily behaviour is largely comprised of automatic routine actions. The frequent repetition of certain behaviours in response to particular contexts can give rise …

Awareness Of Physical Activity Levels And Sedentary Behaviour: An Assessment Of Awareness Of Physical Activity Levels And Sedentary Behaviour Among Parents And Children, Tripat Simran Kaur Grewal

Electronic Thesis and Dissertation Repository

The purpose of this study was to assess awareness of physical activity and sedentary behaviour among parents and children aged 10-13 years. Associations between awareness and factors including age, BMI, gender, and obesity status were also examined. A total of 53 parent-child dyads participated in the study. Agreement between parent and child subjective measures (self-report) and objectively measured physical activity was examined to determine awareness. Most parents (87%) and children (83%) overestimated child moderate-vigorous physical activity (MVPA) beyond 30 minutes/day. The majority of parents (87%) and children (85%) also underestimated child sedentary behaviour by at least 3 hours/day. Older children …

Circadian Rhythms In Reward And Underlying Neural Circuits, Ricardo M. Baltazar

Electronic Thesis and Dissertation Repository

Studies suggest that the circadian timing system exerts an important influence on responses to rewarding stimuli. Diurnal rhythms in the rewarding value of amphetamine and mating behavior were observed, but differed in the pattern of their timing. Daily fluctuations in reward were correlated with oscillations in mesolimbic dopaminergic activity in both the nucleus accumbens (NAc) and ventral tegmental area (VTA), with a peak in NAc coinciding with the peak of sex reward, while the peak in the VTA associated with the peak in amphetamine reward. Also, rhythmic expression of the marker of neural activation, cFos, was observed in NAc, medial …

Functional Characterization Of The Hua2 Gene Family In Arabidopsis Thaliana, Preetam Janakirama

Electronic Thesis and Dissertation Repository

HUA2 encodes a key developmental regulatory protein implicated in the coordination of induction and the maintenance of floral state in Arabidopsis. To gain further insight into the function of HUA2, I have conducted a series of studies aimed at elucidating the molecular function(s) of its individual domains. I show that the PWWP, RPR and CT-proline rich domains within HUA2 are required for the proper regulation of the flowering time phenotype. I also establish that HUA2 interacts with characterized splicing factors (FCA, AtPRP40, RBP45 and UBP1) through its CT-proline rich domain. In addition, I examine the overlap in function between HUA2 …

Small Mammal Foraging And Population Responses To Northern Conifer Mast, Nikhil Lobo

Electronic Thesis and Dissertation Repository

Conifer seeds are a component of the diet of many rodents, and post-dispersal seed predation by rodents is often implicated as a critical constraint on the regeneration of coniferous forests. However, little is known about the effects of conifer seed availability on individual rodents and their populations. The over-arching goal of this dissertation was to investigate the effects and implications of conifer seed production on the foraging and population dynamics of northern small mammals. The predominant conifer study species were white spruce (Picea glauca) and subalpine fir (Abies lasiocarpa), and the main rodents examined were the …

Sunergos1, A Lotus Japonicus Gene Required For Proper Accommodation Of Rhizobial Infection, Hwi Joong Yoon

Electronic Thesis and Dissertation Repository

Here, I characterize a symbiotic mutant of Lotus japonicus, called sunergos1 (suner1), which originated from a har1-1 suppressor screen. I have shown that suner1 supports epidermal infection by rhizobia and initiates nodule primordia organogenesis as in wild-type. However, the infection process is temporarily stalled, such that infection threads fail to ramify within the root cortex and timely release of bacteria inside the nodule primordia cells does not occur. This symbiotic defect is ephemeral and with additional time, functional nodules are formed. Using a combined approach involving map-based cloning and next-generation sequencing, I have shown that the suner1 …

Subcellular Analysis Of The Disulfide Proteome In P66shc Expressing Nerve Cells, Tyler Cann

Electronic Thesis and Dissertation Repository

The longevity associated protein p66Shc has been suggested to regulate organismal lifespan through initiation of apoptotic pathways. Following stress-induced translocation into the mitochondria, p66Shc promotes increased reactive oxygen species (ROS) production and triggers poorly defined downstream signaling events that lead to decreased cell viability. Protein disulfide bonding has recently emerged as aROSdependent post-translational modification that regulates protein function and signaling processes. Using the mouse hippocampal HT-22 cell line, I sought to determine the changes in the disulfide proteome associated with p66Shc mediatedROSproduction. Through Redox 2D-SDSPAGEanalysis of mitochondrial and cytosolic extracts, redox sensitive proteins altered by p66Shc mediatedROSformation were identified. Of …

Investigating The Functional Significance Of Evolutionarily Conserved Protein Motifs Of The Drosophila Melanogaster Hox Protein, Sex Combs Reduced, Lovesha Sivanantharajah

Electronic Thesis and Dissertation Repository

Bilaterans share a common anterior-posterior (A-P) axis that is patterned by the Homeotic selector (Hox) genes. In Drosophila melanogaster, Hox gene expression in spatially restricted domains along the A-P axis of the embryo determines segmental identity. Identifying the genetic mechanisms of HOX control of development is essential for understanding body patterning in animals. I identified and characterized the role of evolutionarily conserved protein domains of the HOX protein, Sex combs reduced (SCR), in protein function. SCR is required for establishing the identity of both the labial and prothoracic segments. To identify regions of functional importance, 15 Scr …