Integrative Biology Commons^™

Feeling Blue: The Effects Of Blue Light Exposure On Reproduction And Physiology In Drosophila Melanogaster, Laura Hampel

Theses and Dissertations (Comprehensive)

Blue light, the wavelengths ranging from ~400-500 nm, is emitted from the sun and more recently, by artificial lights including those in technology. In humans, prolonged exposure to blue light has been consistently linked to circadian rhythm disruption and retinal damage, and has also been associated with changes in neurodegeneration, aging, mortality, and oxidative stress in model organisms. This thesis explores the multifaceted effects of blue light exposure through two independent but complementary approaches. An initial rapid review of the current state of knowledge on blue light induced oxidative stress in humans was conducted. This revealed that the most studied …

Regulation Of Intracellular Sorting Of The Bruno Protein In Drosophila Flight Muscles, Travis Main

Master's Theses

Understanding mechanisms of intracellular sorting is a fundamental inquiry of cell biology. We used the B-body and protein Bruno (Bru) as a model to study the formation of nuclear domains that are membraneless organelles inside the cell nucleus. Specifically, we sought to identify protein sequences that regulate Bru's affinity to B-bodies and protein aggregation. We generated various Bru mutants and subsequently tested them in vivo using fluorescence microscopy. We found that the protein solubility of Bru is determined through an interplay of RNA recognition motifs (RRMs) and intrinsically disordered regions (IDRs). Using truncation analysis, we identified a 31-amino acid region …

Late Embryogenesis Abundant Proteins And Mitochondrial Membranes From An Animal Extremophile: Insights Into Severe Water Stress, John Marcus Anderson

LSU Doctoral Dissertations

This dissertation focuses on two major topics germane to mechanisms by which animals tolerate extreme water stress. First, the impact of transgenic expression of late embryogenesis abundant proteins (LEA) on water stress tolerance of the fruit fly Drosophila melanogaster was investigated. The overall aim was to extend current understanding of the protective properties of LEA proteins documented with isolated cells to a desiccation-sensitive organism during exposure to drying and hyperosmotic stress. Four lines of D. melanogaster were created that expressed transgenes encoding selected LEA proteins originally identified in embryos of the extremophile Artemia franciscana. After 80% tissue water loss, …

Investigation Into The Akirin Subcellular Localization And Developmental Interactions, Riley Wildeman

Master of Science in Integrative Biology Theses

Akirin is a highly conserved nuclear protein ubiquitously expressed in nonfungal eukaryotic species and is known to be involved in many biological processes such as embryonic muscle patterning and innate immune function. Akirin functionality is essential for the prevention of disease and developmental defects. This investigation focused on both the subcellular localization of Akirin based on a putative nuclear localization signal and the genetic interaction between Akirin and the Nucleosome Remodeling Deacetylase (NuRD) complex. Through transfection of Drosophila S2 cells with Akirin mutant constructs we were able to visualize the localization patterns of Akirin and how the patterns relate to …

Drosophila Model To Study Muscle Atrophy, Aaron Aghai

Master of Science in Integrative Biology Theses

Muscle atrophy (MA) is a phenomenon of muscle mass loss due to accelerated protein degradation in muscle fibers. Some pathological conditions, such as chronic inflammation or cancer, induce accelerated MA, which complicates medical treatment, hampers recovery of fragile patients, and ultimately can be the cause of a patient’s death. To gain better control over MA, more information is required about the whole spectrum of genetic factors that can influence MA.

Drosophila provides an excellent platform for genetic screening, although it has somewhat limited utility for MA research since insect muscles lack the level of plasticity found in mammalian muscles. We …

The Functional Conservation Of Frazzled In Insects, Benjamin Wadsworth

Graduate Theses and Dissertations

Axons in the developing embryo receive and react to signals that direct their growth to reach target tissues at specified locations. The signal pathways that direct midline crossing of axons during embryonic development have been comprehensively examined in the past years using the Drosophila ventral nerve cord or the spinal cord as a model system. A number of these signaling mechanisms are conserved, however disparities have been found between species in general strategy or the molecular signals controlling the response of axons to guidance cues.

The Netrin-Frazzled pathway has been shown to aid in midline crossing of axons in the …

The Effects Of A Ketone Body On Synaptic Transmission, Alexandra Elizabeth Stanback

Theses and Dissertations--Biology

The ketogenic diet is commonly used to control epilepsy, especially in cases when medications cannot. The diet typically consists of high fat, low carb, and adequate protein and produces a metabolite called acetoacetate. Seizure activity is characterized by glutamate excitotoxicity and therefore glutamate regulation is a point of research for control of these disorders. Acetoacetate is heavily implicated as the primary molecule responsible for decreasing glutamate in the synapse; it is believed that acetoacetate interferes with the transport of glutamate into the synaptic vesicles. The effects on synaptic transmission at glutamatergic synapses was studied in relation to the ketogenic diet …

Achilles Is A Circadian Clock-Controlled Gene That Regulates The Immune System And Its Rhythmicity In Drosophila, Jiajia Li

Dissertations

Circadian clock is a transcriptional/translational feedback loop that drives the rhythmic expression of downstream mRNAs. Termed “clock-controlled genes,” these molecular outputs of the circadian clock orchestrate cellular, metabolic, and behavioral rhythms. As part of our on-going work to characterize key upstream regulators of circadian mRNA expression, we have identified a novel clock-controlled gene in Drosophila melanogaster, Achilles (Achl), which is rhythmic at the mRNA level in the brain and represses expression of immune response genes, especially anti-microbial peptides in the immune system. Achl knock-down in the brain dramatically elevates expression of crucial immune response genes, including IM1 …

Akirin-Mediated Gene Regulation During Cardiac Development, Austin M. Howard

Master of Science in Integrative Biology Theses

The highly conserved nuclear protein Akirin was previously identified as a cofactor that modulates Twist transcription factor activity during muscle development in Drosophila melanogaster. Akirin mediates an interaction between the Twist transcription factor and the multisubunit Brahma SWI/SNF-class chromatin remodeling complex at control elements of the Dmef2 locus to maintain optimal myogenic gene expression levels. Therefore, Akirin represents a class of novel secondary cofactors that work with transcription machinery to link transcription factor output with chromatin remodeling machinery to facilitate gene expression. Previous work establishes that Twist and Akirin also interact at Twist-responsive control elements of the tinman gene, …