Life Sciences Commons^™

Planting The Chalcone Reductase Family Tree: Identification And Characterization Of Chalcone Reductase Genes In Soybean, Caroline Julia Sepiol

Electronic Thesis and Dissertation Repository

Soybean (Glycine max [L.] Merr) is an important crop grown in Canada, generating $2.4 billion in sales. Though this number may be promising, soybean farmers lose about $50 million worth of yield annually due to root and stem rot disease caused by Phytophthora sojae. Many strategies have been developed to combat the infection; however, these methods are prohibitively expensive. A ‘cost effective’ approach to this problem is to select a trait naturally found in soybean that can increase resistance. One such trait is the increased production of root glyceollins. One of the key enzymes exclusively involved in glyceollin …

Characterizing The Neurotranscriptomic States In Alternative Stress Coping Styles, Ryan Y. Wong, Melissa S. Lamm, John Godwin

Biology Faculty Publications

Background: Animals experience stress in many contexts and often successfully cope. Individuals exhibiting the proactive versus reactive stress coping styles display qualitatively different behavioral and neuroendocrine responses to stressors. The predisposition to exhibiting a particular coping style is due to genetic and environmental factors. In this study we explore the neurotranscriptomic and gene network biases that are associated with differences between zebrafish (Danio rerio) lines selected for proactive and reactive coping styles and reared in a common garden environment.

Results: Using RNA-sequencing we quantified the basal transcriptomes from the brains of wild-derived zebrafish lines selectively bred to exhibit the proactive …

Aversive Stimuli Drive Drug Seeking In A State Of Low Dopamine Tone, Robert C. Twining, Daniel S. Wheeler, Amanda L. Ebben, Andre J. Jacobsen, Mykel A. Robble, John R. Mantsch, Robert A. Wheeler

Biological Sciences Faculty Research and Publications

Background

Stressors negatively impact emotional state and drive drug seeking, in part, by modulating the activity of the mesolimbic dopamine system. Unfortunately, the rapid regulation of dopamine signaling by the aversive stimuli that cause drug seeking is not well characterized. In a series of experiments, we scrutinized the subsecond regulation of dopamine signaling by the aversive stimulus, quinine, and tested its ability to cause cocaine seeking. Additionally, we examined the midbrain regulation of both dopamine signaling and cocaine seeking by the stress-sensitive peptide, corticotropin releasing factor (CRF).

Methods

Combining fast-scan cyclic voltammetry with behavioral pharmacology, we examined the effect of …

The Effects Of Hpa Axis Genetic Variation And Early Life Stress On Cortisol Levels In Preschool Age Children And On Amygdala And Hippocampus Volumes, Reactivity, And Connectivity At School Age, David Pagliaccio

Arts & Sciences Electronic Theses and Dissertations

Internalizing psychopathology has been linked to increased cortisol reactivity and alterations in limbic brain structure and function, yet the mechanisms underlying these alterations are unclear. One key hypothesis is that stress plays a major causal role in these mechanisms. Animal studies find that chronic stress or glucocorticoid administration lead to alterations in hippocampal and amygdala structure and function. Relatedly, life stress is a major risk factors for depression while candidate gene studies have related variation in hypothalamic-pituitary-adrenal (HPA) axis genes to increased prevalence and severity of depression. The present work tested the hypothesis that genetic profile scores combining variance across …

Seasonal Variation In Corticosterone, Stress Responses, And Physiology In The Northern Cardinal Cardinalis Cardinalis, Benjamin Matthew Duckworth

Master's Theses

Seasonal regulation of the adrenocortical response (e.g., ‘stress response’) appears to be ubiquitous in mid- to high-latitude vertebrates. Northern Cardinals (Cardinalis cardinalis) are a Temperate dwelling passerine of Tropical-descent with a wide species range (tropics to Northern Temperate zones). This species encounters a wide variety of environmental conditions and strong seasonality, however corticosterone (CORT, the main adrenal stress hormone) has not been studied with regards to changes in seasonal levels. I initially analyzed samples from cardinals collected between 2007-2011 from the Lake Thoreau Environmental Research and Educational Center (Hattiesburg, Mississippi, USA). The data suggested seasonal differences of CORT, with higher …

Stressed Induced Changes In Karenia Brevis Ribosomal Rna, David Scott Jayroe

Master's Theses

Karenia brevis is a toxic marine dinoflagellate that causes harmful algal blooms (HABs), also known as red tides, in the Gulf of Mexico. These blooms are responsible for massive fish kills, shellfish bed contaminations, adverse human health effects, and vast economic loss. For these reasons, extensive research has gone into understanding the mechanisms and dynamics of bloom behavior by studying K. brevis in the field and in the lab. In order to understand higher order bloom behavior and dynamics it is imperative to understand K. brevis at the cellular level. In growing K. brevis in vitro under a variety of …

Functional Screening Of The Cronobacter Sakazakii Baa-894 Genome Reveals A Role For Prop (Esa_02131) In Carnitine Uptake, Audrey Feeney, Roy D. Sleator

Department of Biological Sciences Publications

Cronobacter sakazakii is a neonatal pathogen responsible for up to 80% of fatalities in infected infants. Low birth weight infants and neonates infected with C. sakazakii suffer necrotizing enterocolitis, bacteraemia and meningitis. The mode of transmission most often associated with infection is powdered infant formula (PIF) which, with an aw of ∼0.2, is too low to allow most microorganisms to persist. Survival of C. sakazakii in environments subject to extreme hyperosmotic stress has previously been attributed to the uptake of compatible solutes including proline and betaine. Herein, we report the construction and screening of a C. sakazakii genome bank and …

Effect Of Environmental Factors On Whole Plant Assimilate Partitioning And Associated Gene Expression, Donald Geiger, K. Koch, Wen-Jang Shieh

Donald R. Geiger

Partitioning of assimilated carbon among sink organs is a critical factor that controls the rate and pattern of plant growth. Time-course measurements of plant and organ growth rates are useful for determining how regulation of carbon partitioning controls plantgrowth. Measuring growth rates over a 24 h period reveals the current pattern of carbon partitioning that can be used to predict growth ratesof specific sinks. Comparison of growth rates among sinks under defined conditions can point out key factors that regulate partitioning ofrecently assimilated carbon among sinks. Internal control of carbonpartitioning by developmental programmes regulates the timing andsite of carbon distribution …

Restraint Stress Alters Pro-Inflammatory Cytokine Expression And Increases Superoxide Dismutase In The Rat Hypothalamus And Hippocampus, Kristina Isabel Barron

Open Access Theses & Dissertations

The impact of restraint stress on changes in cytokine expression and oxidative stress markers in hippocampal (Hipp) and hypothalamic (Hyp) regions of the brain, were assessed in a rat model. In addition, immune and inflammatory variables were assessed in peripheral blood. Male Wistar rats were acutely (30 min) or repeatedly (30 min/d for 14 consecutive days) exposed to a restraint stress, or maintained as non-stressed controls. At the time of sacrifice, whole blood and brain tissues enriched in Hyp or Hipp regions were collected; blood was collected with EDTA as an anticoagulant and centrifuged to yield plasma. All tissue samples …

Influence Of Stress On Substance Use: Age-Associated Variability In Molecular And Behavioral Outcomes, Christina Elizabeth D'Arcy

Open Access Theses & Dissertations

Stress introduces a number of neurological and neurohormonal changes in response to a number of stimuli, and can influence our relationship to rewarding experiences. As such, it holds the potential of promoting vulnerability to addiction to substances such as methamphetamine. While methamphetamine use and abuse has been steadily declining, the fact remains that it and closely related drugs are used in the treatment of conditions such as narcolepsy, weight loss, and attention deficit disorder. In an effort to develop better patient assessment metrics to aid the physician in deciding a course of treatment, we ask the following questions: Do chronic …

Gene Expression Noise In Stress Response As A Survival Strategy In Fluctuating Environments, Javier Garcia-Bernardo

Graduate College Dissertations and Theses

Populations of cells live in uncertain environments, where they encounter large variations in nutrients, oxygen and toxic compounds. In the fluctuating environment, cells can sense their surroundings and express proteins to protect themselves against harmful substances. However, if the stressor appears infrequently or abruptly, sensing can be too costly or too slow, and cells cannot rely solely on it. To hedge against the sudden appearance of a stressor, cell populations can also rely on phenotypic diversification through bet-hedging. In bet-hedging, cells exploit noise in gene expression or use multistable genetic networks to produce an heterogeneous distribution of resistance-conferring protein levels. …