Biology Commons^™

From Chaos To Clockwork: Investigating The Role Of Circadian Genes In Metabolic Development Of 2nd And 3rd Instar Drosophila Larvae, Elliott R. Ruegsegger, Stephanie Hood, Amy Poe

Biological Sciences Undergraduate Honors Theses

Circadian clocks regulate daily physiological and metabolic rhythms across many organisms. In Drosophila melanogaster, the molecular clock involving period (per) and timeless regulates gene expression across 24-hour cycles. Circadian rhythms are well characterized in adult, mature organisms, but their emergence during early developmental stages remain poorly understood. In D. melanogaster, the circadian regulation of sleep and feeding rhythms emerges during the 3rd instar larval stage. This suggests that the circadian regulation of metabolism may also arise during this stage. Further, the metabolic consequences of circadian clock disruptions during this developmentally rich period remain unclear. This research aimed to …

A Series Of Investigations On The L. Cornutus Host System And Bivesiculid Sp. Cercariae, Briana K. Zaffiro

All HCAS Student Capstones, Theses, and Dissertations

Rising global temperatures are likely modulating parasite-host interactions, yet the direction and magnitude of these changes remain uncertain. Rarely are these interactions viewed from both a host and parasite perspective. Using both CT_max, or Critical Thermal Maximum, and Clark-type polarographic oxygen microelectrodes, the physiological metabolic effects are investigated. CT_max is examined in Common Shiners, Luxilis cornutus, and is shown to be modulated by parasitism: uninfected fish had the highest CT_max average of 37.0°C, whereas heavily infected fish had decreased CT_max averaging 35°C. Prior to the parasite metabolic investigation, a suitable medium was determined, as …

Energy Management And Water Balance In Migrating Hummingbirds, Shayne R. Halter

Biology ETDs

Small body size and rapid metabolism make annual migrations challenging for North American hummingbirds. Many of these birds make annual journeys of over 10,000 km. During migrations, hummingbirds use stopover sites, where they remain for several days to accumulate body fat. At these stopovers, they often encounter uncertainties in food resources, competition, and weather. To save energy, hummingbirds sometimes enter nocturnal torpor. My dissertation uses respirometry data, lipid measurements from Quantitative Magnetic Resonance, and feather hydrogen stable isotopes to understand how energy levels, migration patterns, torpor use, and water balance interact in four species of migrating hummingbirds. I discovered lipid …

Pfas And Western Diet Effects On Adolescent Rat Feeding And Metabolism, Whesli Kim

Theses and Dissertations from DePaul University

Per- and polyfluoroalkyl substances (PFAS) are a class of widespread persistent organic pollutants associated with metabolic and neural dysfunction in humans. These processes are also affected by Western diet high sugar high fat contents. However, interacting effects of PFAS exposure and Western diet on metabolic regulation and feeding behavior have not been tested. Exposure to PFAS is high during sensitive gestational and neonatal periods of development. Adolescence is a key period where nutritional demands shift, eating habits are established, and gonadal hormones change. This study tests the hypothesis that early life exposure to PFOS alters adolescent metabolic function and feeding …

Mitochondria Dynamics In Microglia During Health, Inflammation, And Aging, Alicia Nicole Pietramale

Dartmouth College Ph.D Dissertations

Microglia continually surveil the brain, allowing for rapid detection of tissue damage or infection. Microglial metabolism is linked to tissue homeostasis, yet how mitochondria are subcellularly partitioned in microglia and dynamically reorganize during surveillance, injury responses, and phagocytic engulfment in the intact brain has remained unclear. In this dissertation, I combine intravital imaging, ultrastructural analyses, and metabolic and cytoskeletal markers to investigate how mitochondrial organization relates to microglial function across health, inflammation, and aging.

I first show that microglial processes diverge in their mitochondrial content, with some containing multiple mitochondria while others are completely void. This heterogeneous partitioning is conserved …

Love In The Fast Lane: Rapid Physiological Senescence At Sexual Maturity In Male Colorado Brown Tarantulas (Aphonopelma Hentzi), Spencer Poscente

Master's Theses and Doctoral Dissertations

Sexual dimorphism in longevity represents a striking example of natural selection favoring reproductive success over survival: in Colorado brown tarantulas (Aphonopelma hentzi), females live over two decades while males survive just months after reaching sexual maturity. I collected sexually mature males at three time points (August, September, October) across two years and quantified metabolic rates, locomotor performance, and survival under controlled laboratory conditions. This thesis comprises two articles examining complementary dimensions of that decline: metabolic senescence and locomotor performance. Open-flow respirometry revealed significant seasonal shifts: minimum metabolic rate increased through October, and metabolic scope peaked in September before declining. Survival …

Impact Of S-Phase Kinase Protien 2 Blockades On Hematopoetic Stem Cell Metabolism, Nicole Elmaraghy

Electronic Theses, Projects, and Dissertations

Hematopoietic stem and progenitor cells (HSPCs) quiescence is vital for the success of bone marrow transplantation, as it preserves long term self- renewal and prevents premature exhaustion (Takubo et al., 2013; Wilson et al., 2008). However, bone marrow transplant (BMT) failure remains a clinical challenge, often due to lack of long-term engraftment and insufficient stress reliance. Both of these characteristics are tightly linked to disrupted stem cell quiescence and metabolic imbalance (Anso et al., 2017; Vannini et al., 2016). One key player is S-phase kinase protein (SKP2), an E3 ubiquitin ligase that targets cell cycle inhibitors, like p27, for proteosome …

Improved Autofluorescence Lifetime Decay Analysis For Identification Of Cellular Autofluorescence Biomarkers For Label-Free, Single-Cell Assessment Of Mitochondrial Membrane Potential, Olivia Isabel Kolenc

Graduate Theses and Dissertations

Optical imaging of metabolism using the autofluorescence of the metabolic cofactors NADH, NADPH, and FAD has a wide range of sensitivities and the capability to collect a great deal of metabolic information. Multiphoton microscopy (MPM) is a non-invasive, label-free optical imaging technique capable of performing fluorescence lifetime imaging (FLIM) using time correlated single photon counting (TCSPC). However, autofluorescence FLIM presents a challenge in collecting sufficient photons to provide adequate signal to noise ratios (SNR) for analysis. Additionally, the specificity of autofluorescence biomarkers of metabolism has not been well-defined. Contextualizing these autofluorescence measures using established functional biomarkers can improve interpretability of …

Understanding Loss Of Beta-Cell Identity And Progression Of Diabetes In Polygenic Mouse Models Of T2dm, Sumitkumar Patel

Arts & Sciences Graduate Student Theses and Dissertations

Type 2 diabetes (T2DM) is caused by the complex interaction of multiple genes and environmental factors. T2DM is characterized by hyperglycemia, insulin resistance in peripheral tissues and impaired insulin secretion by the pancreas. While the decline in insulin production and secretion was previously attributed to apoptosis of insulin-producing β-cells, recent studies indicate that β cell apoptosis rates are relatively low in diabetes. In this dissertation, I investigated β-cell failure in diabetes using KK and KKAy mouse models of polygenic T2DM, which spontaneously develop hyperglycemia, glucose intolerance, glucosuria, impaired insulin secretion and insulin resistance. I found that β-cell failure in KK …

Metabolic Responses Of Adipose-Derived Stem Cells In Collagen I Hydrogels, Caroline R. King

Biological Sciences Undergraduate Honors Theses

Peripheral nerve injury affects approximately 44 in 1 million people in the United States every year and can lead to incomplete nerve recovery and loss of motor and sensory function. A significant amount of energy is required for nerve injury repair. A lack of energy allocation to the injury site hinders repair. Current treatments include hollow nerve guidance conduits, decellularized nerve grafts, and autografts. However, they are limited by factors such as donor site morbidity and sustained immunosuppressive treatments. Using three-dimensional collagen I hydrogels laden with adipose-derived stem cells (ASCs) can assist in neural regeneration. Three-dimensional collagen scaffolds aim to …

The Role Of Ucp2 In Pancreatic Cancer Metabolism And Its Potential As A Radiosensitizer, Emily Rieff

Dissertations and Theses (Open Access)

Uncoupling protein 2 (UCP2) is a mitochondrial protein that regulates the flow of protons down the gradient established by the electron transport chain (ETC) without generating ATP, thus uncoupling the proton gradient from ATP generation. In tumors, specifically pancreatic cancer (PDAC), the ETC is highly stimulated to generate the copious ATP needed by the tumor to grow. However, extended ETC use increases reactive oxygen species (ROS), and if left unchecked, results in cell death. To evade this, PDAC employs antioxidant strategies, including upregulating UCP2 in tumor cells. In addition to its uncoupling function, UCP2 indirectly controls ROS levels by maintaining …

Murine Studies On Ketogenic Modulation Of Metabolism And Epigenetics In Olfaction- Based Learning, Lps Inflammatory Response, And Sex Dimorphisms In Dietary Response, Sara E. H. Moss

USF Tampa Graduate Theses and Dissertations

Ketogenic diets are well-established therapeutic interventions for epilepsy, with documented neuroprotective effects arising from their metabolic, antioxidant and anti-inflammatory properties. Beyond epilepsy, ketogenic therapies are under investigation for various conditions including Alzheimer disease, cancer, diabetes, and cardiovascular disease. These diets suppress insulin levels and shift metabolic physiology toward fat and ketone body metabolism. This elevates circulating levels of ketone bodies, namely beta-hydroxybutyrate, acetoacetate, and acetone, which serve as both energy substrates and signaling molecules. The state of elevated ketone bodies (ketosis) can be achieved with various formulations of a ketogenic diet as well as exogenous ketone supplementation, though the signaling …

Hydrolysis Of The Acetyl-Coa Allosteric Activator By Staphylococcus Aureus Pyruvate Carboxylase, Amanda J. Laseke, Jeremy R. Lohman, Martin St. Maurice

Biological Sciences Faculty Research and Publications

Pyruvate carboxylase (PC) catalyzes the carboxylation of pyruvate to oxaloacetate which serves as an important anaplerotic reaction to replenish citric acid cycle intermediates. In most organisms, the PC-catalyzed reaction is allosterically activated by acetyl-coenzyme A. It has previously been reported that vertebrate PC can catalyze the hydrolysis of acetyl-CoA, offering a potential means for the enzyme to attenuate its allosteric activation. However, in the years since this initial report, there has been no further investigation of this phenomenon. The allosteric binding site for acetyl-CoA is now well characterized, enabling more detailed studies on acetyl-CoA hydrolysis at the allosteric site. Here, …

Circadian And Age-Related Variations Of Amino Acids Levels In Drosophila Brains: Correlations And Descriptive Dimensions, Sandrine Parrot, Jacob Crehan, Chloé Aman, Philippe De Deurwaerdère, Matthew S. Thimgan, Laurent Seugnet

Biological Sciences Faculty Research & Creative Works

A comprehensive view of whole-brain amino acid levels holds the potential to provide valuable insights into the brain's state, given the mutual interconnections through metabolism, food intake, and neurotransmission. We tested this concept by evaluating free amino acid levels in single Drosophila brains across 24 h and at two different ages. A large proportion of these amino acids displayed time-of-day variations, and a subset exhibited age-dependent variations. Cross-correlation analysis of the data sets confirmed broad time-of-day and age dependent interconnections between amino acids. Factor Analysis of Mixed Data revealed further data structuration along key amino acids. For example, 50% of …

Cellular Responses Of Astrangia Poculata (Ellis And Solander, 1786) And Its Symbiont To Experimental Heat Stress, Tyler E. Harman, Daniel Barshis, Briana Hauff Salas, Kevin B. Strychar

Biological Sciences Faculty Publications

Climate change has had devastating effects on tropical coral reefs; however, much less is known regarding how heat stress affects temperate coral. This research focuses on Astrangia poculata (Ellis and Solander, 1786) collected from Narragansett Bay, RI, during the summer and winter seasons and understanding the effect of experimental thermal extremes (i.e., 26 °C) on seasonally different populations. Photosynthetic efficiency (Fv/Fm), symbiont density (via an inverse relationship with pixel intensity), and oxidative stress via reactive oxygen species (ROS) concentrations were measured on symbiotic and aposymbiotic A. poculata. Higher Fv/Fm rates were observed in summer- vs. winter-collected corals (p ≤ …

Anoxia And Re-Oxygenation At Colder Temperatures In Goldfish (Carassius Auratus): Effects On Oxidative Stress And Metabolites, Matthew E. Trzcinski

Theses and Dissertations (Comprehensive)

Under the ice of ponds and lakes, goldfish (Carassius auratus) can survive weeks of anoxia at low temperatures by conserving ATP and by reducing their metabolic rate and relying on liver glycogen stores to meet their ATP demands using glycolysis. The following period of re-oxygenation is also known to be damaging in most vertebrates because it can lead to the generation of reactive oxygen species (ROS) that can cause oxidative damage to lipids, proteins and nucleic acids. Anoxia tolerant vertebrates such as the goldfish and crucian carp (Carassius carassius) accumulate reduced molecules with anoxia, overwhelming the …

Accurate Body Weight Class Prediction From Mirna And Gene Expression In Blood And Saliva Samples, Kimberly Lettner

Master of Science in Forensic Science Directed Research Projects

miRNA interference on protein abundance related to glucose uptake and lipid production has been evaluated in biomedical research and linked to metabolic disorders like severe obesity. The direct regulation of protein abundance caused by miRNAs on a person’s metabolism can lead to an increased weight and overall size. Body size, measured by BMI, provides additional physical descriptions that can be combined with hair color, eye color, age, and skin pigment to aid investigations of unidentified remains or unknown suspects not found in a database. The purpose of this project was to evaluate the miRNA expression of target biomarkers in dried …

Comparing Metabolism And Hypoxia Tolerance Of Native And Non-Native Florida Freshwater Fishes In Climate Change Scenarios, Benjamin A. Share

All HCAS Student Capstones, Theses, and Dissertations

As climate change brings rising water temperatures and lower dissolved oxygen (DO) concentrations to freshwater bodies, it has become increasingly important to understand how this will affect ecosystems with established non-native or invasive species. Fishes of the family Cichlidae are the most pervasive non-native fishes in the Everglades and may increase their range further north under a changing climate. To better understand potential invasibility and competition with native fishes, the metabolism and hypoxia tolerance of non-native Blue Tilapia Oreochromis aureus was compared to native Bluegill Lepomis macrochirus when acclimated across a range of seasonal and projected temperatures. Intermittent-flow respirometry was …

The Anti-Diabetic Drug Metformin Disrupts Feeding And Sleeping Behaviors In Drosophila Melanogaster, Lucas Fitzgerald

The Cardinal Edge

Dimethylbiguanide, also known as metformin, is the single most prescribed oral treatment for non-insulin dependent diabetes mellitus, or type 2 diabetes, in western countries. The primary mechanism of action that metformin acts through is the activation of AMP kinase, an important regulator of energy homeostasis. While the anti-diabetic effects of metformin are well documented, its effects on feeding and sleeping behaviors are not well characterized. Using the model organism Drosophila melanogaster, the mean daily quantity of food consumed was measured and compared between groups treated with several dosages of metformin. Feeding interactions such as meal frequency and length were …

Life, Death And Energy: What Does Nature Select?, James H. Brown, Chen Hou, Charles A.S. Hall, Joseph R. Burger

Biological Sciences Faculty Research & Creative Works

Evolutionary biology is poised for a third major synthesis. The first presented Darwin's evidence from natural history. The second incorporated genetic mechanisms. The third will be based on energy and biophysical processes. It should include the equal fitness paradigm (EFP), which quantifies how organisms convert biomass into surviving offspring. Natural selection tends to maximize energetic fitness, formula presented, where formula presented is mass-specific rate of cohort biomass production, formula presented is generation time, formula presented is fraction of cohort production that is passed to surviving offspring, and formula presented is energy density of biomas. At steady state, parents replace themselves …

Insulin-Independent Regulation Of Type 1 Diabetes Via Large Brown Adipocyte-Secreted Proteins And The Novel Glucagon Regulator, Nidogen2, Jeongmin Lee

Arts & Sciences Graduate Student Theses and Dissertations

Current treatments for type 1 diabetes (T1D) focus on insulin replacement. We demonstrate the therapeutic potential of a secreted protein fraction from embryonic brown adipose tissue (BAT), independent of insulin. The large molecular weight secreted fraction mediates insulin receptor-dependent recovery of euglycemia in a T1D animal model, nonobese diabetic (NOD) mice, by suppressing glucagon secretion. This fraction also promotes white adipocyte differentiation and browning, maintains healthy BAT, and enhances glucose uptake in adipose tissue, skeletal muscle, and liver. From this fraction, we identify nidogen-2 as a critical BAT-secreted protein that reverses hyperglycemia in NOD mice, inhibits glucagon secretion from pancreatic …

The Anti-Diabetic Drug Metformin Disrupts Feeding And Sleeping Behaviors In Drosophila Melanogaster., Lucas Fitzgerald

College of Arts & Sciences Senior Theses

Dimethylbiguanide, also known as metformin, is the single most prescribed oral treatment for non-insulin dependent diabetes mellitus, or type 2 diabetes, in Western countries. The primary mechanism of action that metformin acts through is the activation of AMP kinase, an important regulator of energy homeostasis. While the anti-diabetic effects of metformin are well documented, its effects on feeding and sleeping behaviors are not well characterized. Using the model organism Drosophila melanogaster, the mean daily quantity of food consumed was measured and compared between groups treated with several dosages of metformin. Feeding interactions such as meal frequency and length were …

Avian Extraembryonic Membranes Respond To Yolk Corticosterone Early In Development, Emily P. Harders, Mitch Agustin, Ryan T. Paitz

Faculty Publications – Biological Sciences

During times of maternal stress, developing embryos can be exposed to elevated levels of glucocorticoids which can affect development and permanently alter offspring phenotype. In placental species, the placenta mediates fetal exposure to maternal glucocorticoids via metabolism, yet the placenta itself responds to glucocorticoids to regulate offspring growth and development. In oviparous species, maternal glucocorticoids can be deposited into the egg yolk and are metabolized early in development. This metabolism is mediated by the extraembryonic membranes, but it is unknown if the extraembryonic membranes also respond to maternal glucocorticoids in a way comparable to the placenta. In this study, we …

Identification Of Mimas, A Multifunctional Mega-Assembly Integrating Metabolic And Respiratory Biogenesis Factors Of Mitochondria, Rosemary A. Stuart

Biological Sciences Faculty Research and Publications

The mitochondrial inner membrane plays central roles in bioenergetics and metabolism and contains several established membrane protein complexes. Here, we report the identification of a mega-complex of the inner membrane, termed mitochondrial multifunctional assembly (MIMAS). Its large size of 3 MDa explains why MIMAS has escaped detection in the analysis of mitochondria so far. MIMAS combines proteins of diverse functions from respiratory chain assembly to metabolite transport, dehydrogenases, and lipid biosynthesis but not the large established supercomplexes of the respiratory chain, ATP synthase, or prohibitin scaffold. MIMAS integrity depends on the non-bilayer phospholipid phosphatidylethanolamine, in contrast to respiratory supercomplexes whose …

Linking Microbial Community Assembly In Flowers With Function Under Diverse Environmental Conditions: A Case Study Involving Erwinia Amylovora, Christopher Skylar Mcdaniel

All Graduate Theses and Dissertations, Fall 2023 to Present

Fire blight, a devastating disease of pome fruit trees caused by the bacterium Erwinia amylovora, can cause millions of dollars in losses for producers each year around the globe. Management approaches that involve use of antibiotics, such as streptomycin, can be effective; although concerns exist over pollinator and crop health when using them regularly. Recently, there have been developments that allow for biological agents such as microbes to curtail fire blight infection. These agents work by competing with Erwinia for resources or space, producing antibacterial compounds, or even killing Erwinia cells on contact. Unfortunately, these agents do not yet …

Dfcp1 Regulates Lipid Droplet Catabolism In An Ntpase-Dependent Manner, Victoria Anne Ismail

Arts & Sciences Graduate Student Theses and Dissertations

Lipid Droplets (LDs) are lipid storage organelles that can be readily tapped to resupply cells with energy or lipid building blocks, and, therefore, play a central role in cellular metabolism. It has emerged that Double FYVE Domain Containing Protein 1 (DFCP1), which has routinely been used as a marker for early autophagy, is an LD-associated protein and is implicated in establishing contacts between the endoplasmic reticulum (ER) and LDs, but little is known about DFCP1’s function or how it influences either autophagy or LD metabolism. Here, we show that DFCP1 contains a novel NTPase domain that regulates its assembly onto …

Obesity And Renal Cell Carcinoma: Biological Mechanisms And Perspectives, Neha Venkatesh, Alberto Martini, Jennifer L Mcquade, Pavlos Msaouel, Andrew W Hahn

Faculty, Staff and Student Publications

Obesity, defined by body mass index (BMI), is an established risk factor for specific renal cell carcinoma (RCC) subtypes such as clear cell RCC, the most common RCC histology. Many studies have identified an association between obesity and improved survival after diagnosis of RCC, a potential "obesity paradox." Clinically, there is uncertainty whether improved outcomes observed after diagnosis are driven by stage, type of treatment received, or artifacts of longitudinal changes in weight and body composition. The biological mechanisms underlying obesity's influence on RCC are not fully established, but multiomic and mechanistic studies suggest an impact on tumor metabolism, particularly …

A New Frontier For Fat: Dietary Palmitic Acid Induces Innate Immune Memory, Amy L. Seufert, Brooke A. Napier

Biology Faculty Publications and Presentations

Dietary saturated fats have recently been appreciated for their ability to modify innate immune cell function, including monocytes, macrophages, and neutrophils. Many dietary saturated fatty acids (SFAs) embark on a unique pathway through the lymphatics following digestion, and this makes them intriguing candidates for inflammatory regulation during homeostasis and disease. Specifically, palmitic acid (PA) and diets enriched in PA have recently been implicated in driving innate immune memory in mice. PA has been shown to induce long-lasting hyper-inflammatory capacity against secondary microbial stimuli in vitro and in vivo, and PA-enriched diets alter the developmental trajectory of stem cell progenitors in …

Rna Virus-Mediated Changes In Organismal Oxygen Consumption Rate In Young And Old Drosophila Melanogaster Males, Eli Hagedorn, Dean Bunnell, Beate Henschel, Daniel Smith Jr, Stephanie Dickinson, Andrew Brown, Maria De Luca, Ashley Turner, Stanislava Chtarbanova

Research, Publications & Creative Work

Aging is accompanied by increased susceptibility to infections including with viral pathogens resulting in higher morbidity and mortality among the elderly. Significant changes in host metabolism can take place following virus infection. Efficient immune responses are energetically costly, and viruses divert host molecular resources to promote their own replication. Virus-induced metabolic reprogramming could impact infection outcomes, however, how this is affected by aging and impacts organismal survival remains poorly understood. RNA virus infection of Drosophila melanogaster with Flock House virus (FHV) is an effective model to study antiviral responses with age, where older flies die faster than younger flies due …

Changes In Metal-Chelating Metabolites Induced By Drought And A Root Microbiome In Wheat, Anne J. Anderson, Joshua M. Hortin, Astrid R. Jacobson, David W. Britt, Joan E. Mclean

Biological Engineering Faculty Publications

The essential metals Cu, Zn, and Fe are involved in many activities required for normal and stress responses in plants and their microbiomes. This paper focuses on how drought and microbial root colonization influence shoot and rhizosphere metabolites with metal-chelation properties. Wheat seedlings, with and without a pseudomonad microbiome, were grown with normal watering or under water-deficit conditions. At harvest, metal-chelating metabolites (amino acids, low molecular weight organic acids (LMWOAs), phenolic acids, and the wheat siderophore) were assessed in shoots and rhizosphere solutions. Shoots accumulated amino acids with drought, but metabolites changed little due to microbial colonization, whereas the active …