Physiology Commons^™

Organizational Effects Of Defeminizing Toxicants: Lessons Learned From An Environmental Sentinel Organism, The Fathead Minnow., Jonathan Ali

Theses & Dissertations

Endocrine disrupting compounds (EDCs) are chemicals that interfere with hormone function and are increasingly detected in aquatic environments, where they elicit adverse effects from exposed organisms. The toxicological effects of EDCs can be described as either activational (reversible) or organizational (irreversible), where the latter are associated with adverse outcomes in reproductive performance of adult fish. However, few studies have investigated the organizational impacts of anti-estrogenic or “defeminizing” EDCs, e.g. agrichemicals or pharmacological agents, in an environmentally-relevant or “sentinel” species. The objective of this study was to investigate the impacts of early-life EDC-initiated changes in estrogenic gene expression on organizational effects …

Insights Into The Therapeutic Potential Of Salt Inducible Kinase 1: A Novel Mechanism Of Metabolic Control, Randi Fitzgibbon

Dissertations and Theses (Open Access)

Salt inducible kinase 1 (SIK1) has been considered a stress-inducible kinase since it was first cloned in 1999. Continued efforts since this time have been dedicated to characterizing the structure and function of SIK1. Such research has laid the ground work for our understanding of SIK1 action and regulation in tissue and stimuli dependent manners. The fundamental findings of this dissertation continue in this tradition and include investigations of SIK1 regulatory mechanisms in skeletal muscle cells, the cellular and physiological effects of SIK1 loss of function in vitro and in vivo, and intracellular metabolic and mitochondrial regulation by this …

Associative Learning Contributes To The Increased Water Intake Observed After Daily Injections Of Angiotensin Ii, Maggie Postolache, Jessica Santollo, Derek Daniels

Biology Faculty Publications

Daily injections of angiotensin II (AngII) cause a progressive increase of water intake that resembles a classically ascribed non-associative sensitization. Consistent with the presumption that the observed increase in intake was sensitization, we hypothesized that it resulted from a pharmacological interaction between AngII and its receptor. To test this hypothesis, and remove the influence of drinking itself, we implemented a delay in water access after injection of AngII (icv) on four consecutive ‘induction days,’ and then measured intake on the next day (‘test day’) when rats were allowed to drink immediately after AngII. The delay in water access effectively reduced …

Effects Of Winter And Summer Thermal Variability Regimes On Growth And Metabolism In Brook Trout (Salvelinus Fontinalis), Spenser Chicoine

All NMU Master's Theses

Brook trout (Salvelinus fontinalis) is a cold-water species with a narrow range of thermal tolerance. Climate change projections show that in addition to increases in average temperatures worldwide, daily thermal variability is increasing. Such conditions could prove challenging for brook trout and other ectotherms that are adapted to small temperature ranges. This research investigates how the growth and metabolic capacities of brook trout respond to long-term exposure to thermal variation. Groups of fish were reared under three thermal regimes: constant baily temperature, a 4°C daily range, and an 8°C daily range in a controlled lab setting. This was …

There’S More Than One Way To Climb A Tree: Limb Length And Microhabitat Use In Lizards With Toe Pads, Travis J. Hagey, Scott Hart, Matthew Vickers, Luke J. Harmon, Lin Schwarzkopf

Biology

Ecomorphology links microhabitat and morphology. By comparing ecomorphological associations across clades, we can investigate the extent to which evolution can produce similar solutions in response to similar challenges. While Anolis lizards represent a well-studied example of repeated convergent evolution, very few studies have investigated the ecomorphology of geckos. Similar to anoles, gekkonid lizards have independently evolved adhesive toe pads and many species are scansorial. We quantified gecko and anole limb length and microhabitat use, finding that geckos tend to have shorter limbs than anoles. Combining these measurements with microhabitat observations of geckos in Queensland, Australia, we observed geckos using similar …

Proteomic Analysis Of The Crustacean Molting Gland (Y-Organ) Over The Course Of The Molt Cycle, Talia B. Head

Master's Theses

Molting in crustaceans is a highly complex physiological process involving negative regulation by two paired endocrine glands, the X-organ/sinus gland complex (XO/SG) and the Y-organ (YO). The XO/SG complex is responsible for making molt-inhibiting hormone (MIH) which negatively regulates synthesis of the molting hormones, ecdysteroids, by the YO. Analysis of gene expression in the XOs and YOs has led to the development of a proposed molecular signaling pathway which regulates ecdysteroidogenesis and subsequent molting in crustaceans. In this study, changes in protein abundance in the YO were characterized over the course of a molt cycle (intermolt, early premolt, mid premolt, …

Designing An Authentic Behavioral Research Experience In The Classroom Using Siamese Fighting Fish, Betta Splendens, Gianne Souza, Ronald M. Coleman

STAR Program Research Presentations

Recently there have been major shifts in biology education towards emphasizing the teaching of the scientific process to more closely reflect actual scientific practices. Authentic research experiences require the development of many higher order cognitive skills. Creating an authentic research experience that appropriately scaffolds the development of these complex skills while engaging individual student motivation remains challenging in classroom settings. Some common challenges include limited time available for working with large numbers of students, cramped working areas, and limited funding and materials resources. Using the Siamese Fighting Fish, Betta splendens, we have created an economically viable authentic animal behavioral …

The Chondrocyte Channelome: A Novel Ion Channel Candidate In The Pathogenesis Of Pectus Deformities, Anthony J. Asmar

Biological Sciences Theses & Dissertations

Costal cartilage is a type of rod-like hyaline cartilage connecting the ribs to the sternum. The chest wall deformities pectus excavatum (PE) and pectus carinatum (PC) involve displacement of the sternum causing a depression or protrusion of the chest. There is little knowledge about costal cartilage and pectus deformities with much of its understanding based on assumptions from articular cartilage. Chondrocytes are subjected to a constantly changing environment with fluctuations in pH and osmolarity. Ion channels detect these changes and in turn regulate proliferation, differentiation, and extracellular matrix production. Using ion channel qPCR arrays, we produced expression profiles for normal, …

Tempo And Mode Of Performance Evolution Across Multiple Independent Origins Of Adhesive Toe Pads In Lizards, Travis J. Hagey, Josef C. Uyeda, Kristen E. Crandell, Jorn A. Cheney, Kellar Autumn, Luke J. Harmon

Biology

Understanding macroevolutionary dynamics of trait evolution is an important endeavor in evolutionary biology. Ecological opportunity can liberate a trait as it diversifies through trait space, while genetic and selective constraints can limit diversification. While many studies have examined the dynamics of morphological traits, diverse morphological traits may yield the same or similar performance and as performance is often more proximately the target of selection, examining only morphology may give an incomplete understanding of evolutionary dynamics. Here, we ask whether convergent evolution of pad-bearing lizards has followed similar evolutionary dynamics, or whether independent origins are accompanied by unique constraints and selective …

The Interaction Of Scale And Temperature In Elastically Powered Movements, Jeffrey P. Olberding

USF Tampa Graduate Theses and Dissertations

For many animals, rapid movements place high power demands on underlying muscles. Storage of muscle energy in elastic structures and the subsequent rapid release of that energy can effectively amplify muscle power. Elastic recoil can also confer thermal robustness to performance in behaviors occurring at variable temperatures. Muscle contractile performance tends to decrease at lower temperatures, but elastic recoil is less affected by temperature. Here I examine the impacts of temperature and scale in systems using elastic recoil and I explore possible interactive effects on movement performance.

I explored the role that muscle contractile properties play in the differences in …

Costs Of Group Locomotion: How Infant-Carrying And Group Members Mediate Walking Speed Decisions In North American And East African Populations, Leah M. Bouterse

Honors Projects

A major portion of humans’ activity-based energy expenditure is taken up by locomotion, particularly walking. Humans can offset the energetic expenditure of walking in numerous ways, both evolutionary (such as changes in body shape) and culturally. Behaviorally, people can choose to walk in a variety of ways, including alone or with a group, carrying loads, and walking quickly or more slowly. All of these behaviors have energetic outcomes and as such can be important windows into how populations and groups adjust to different constraints. While sex differences in speed of paired walkers have been established by others, the dynamics of …

Hibernator And Non-Hibernator Responses To Acute Changes In Water Intake, Sydni S. Andruskiewicz

All College Thesis Program, 2016-2019

Hibernating animals undergo dramatic changes in metabolic rates during torpor. One of most notable changes in these animals is the ability to maintain blood pressure and perfuse certain organs. Consequentially, blood perfusion to the kidneys is greatly decreased and the ability to concentrate urine halts. However, about once a week, torpor is interrupted and the animal becomes active to rewarm itself about once a week. This activity induces rapid regeneration of the extracellular osmotic gradient of the kidney, and allows urine to be concentrated. Nonetheless, regaining the extracellular osmotic gradient creates a potentially fatal consequence to the kidney cells. To …

Factors Influencing Induction Of Desiccation Tolerance In Bryophytes: Redefining Fundamental Aspects Of The Organism’S Relationship With The Environment In Xeric Habitats, Joshua Lee Greenwood

UNLV Theses, Dissertations, Professional Papers, and Capstones

If one wishes to understand the ecological role, range, habitat preferences, selective pressures, reproduction, response to climate change, and the potential for survival under climactic change, range expansion and range contraction for species and populations of bryophytes, an understanding of their survival of the desiccated state, is essential. In order to further our understanding of desiccation tolerance in mosses, three projects were undertaken. The first of these investigated the nature of desiccation tolerance in mosses, specifically if desiccation tolerance can be induced; thereby providing a desiccation tolerant phenotype in a moss species generally considered desiccation sensitive (Physcomitrella patens, the model …

High-Fat Feeding Does Not Disrupt Daily Rhythms In Female Mice Because Of Protection By Ovarian Hormones, Brian T. Palmisano, John M. Stafford, Julie S. Pendergast

Biology Faculty Publications

Obesity in women is increased by the loss of circulating estrogen after menopause. Shift work, which disrupts circadian rhythms, also increases the risk for obesity. It is not known whether ovarian hormones interact with the circadian system to protect females from obesity. During high-fat feeding, male C57BL/6J mice develop profound obesity and disruption of daily rhythms. Since C57BL/6J female mice did not develop diet-induced obesity (during 8 weeks of high-fat feeding), we first determined if daily rhythms in female mice were resistant to disruption from high-fat diet. We fed female PERIOD2:LUCIFERASE mice 45% high-fat diet for 1 week and measured …

Blubber Transciptome Response To Acute Stress Axis Activation Involves Transient Charges In Adipogenesis And Lipolysis In Fast-Adapted Marine Mammal, J. I. Khudyakov, C. D. Champagne, L. M. Meneghetti, D. E. Crocker

Biological Sciences Faculty Publications

Stress can compromise an animal's ability to conserve metabolic stores and participate in energy-demanding activities that are critical for fitness. Understanding how wild animals, especially those already experiencing physiological extremes (e.g. fasting), regulate stress responses is critical for evaluating the impacts of anthropogenic disturbance on physiology and fitness, key challenges for conservation. However, studies of stress in wildlife are often limited to baseline endocrine measurements and few have investigated stress effects in fasting-adapted species. We examined downstream molecular consequences of hypothalamic-pituitary-adrenal (HPA) axis activation by exogenous adrenocorticotropic hormone (ACTH) in blubber of northern elephant seals due to the ease of …

Mitochondria Mediate Cell Membrane Repair And Contribute To Duchenne Muscular Dystrophy., Maria C Vila, Sree Rayavarapu, Marshall W Hogarth, Jack H Van Der Meulen, Adam Horn, Aurelia Defour, Shin'ichi Takeda, Kristy J. Brown, Yetrib Hathout, Kanneboyina Nagaraju, Jyoti K. Jaiswal

Genomics and Precision Medicine Faculty Publications

Dystrophin deficiency is the genetic basis for Duchenne muscular dystrophy (DMD), but the cellular basis of progressive myofiber death in DMD is not fully understood. Using two dystrophin-deficient mdx mouse models, we find that the mitochondrial dysfunction is among the earliest cellular deficits of mdx muscles. Mitochondria in dystrophic myofibers also respond poorly to sarcolemmal injury. These mitochondrial deficits reduce the ability of dystrophic muscle cell membranes to repair and are associated with a compensatory increase in dysferlin-mediated membrane repair proteins. Dysferlin deficit in mdx mice further compromises myofiber cell membrane repair and enhances the muscle pathology at an asymptomatic …

Hovering In The Heat: Effects Of Environmental Temperature On Heat Regulation In Foraging Hummingbirds, Don R. Powers, Kathleen M. Langland, Susan M. Wethington, Sean D. Powers, Catherine H. Graham, Bret W. Tobalske

Faculty Publications - Department of Biological & Molecular Science

At high temperature (greater than 40°C) endotherms experience reduced passive heat dissipation (radiation, conduction and convection) and increased reliance on evaporative heat loss. High temperatures challenge flying birds due to heat produced by wing muscles. Hummingbirds depend on flight for foraging, yet inhabit hot regions. We used infrared thermography to explore how lower passive heat dissipation during flight impacts body-heat management in broad-billed (Cynanthus latirostris, 3.0 g), black-chinned (Archilochus alexandri, 3.0 g), Rivoli’s (Eugenes fulgens, 7.5 g) and blue-throated (Lampornis clemenciae, 8.0 g) hummingbirds in southeastern Arizona and calliope hummingbirds (Selasphorus calliope, 2.6 g) in Montana. Thermal gradients driving passive …

Transient Alt Activation Protects Human Primary Cells From Chromosome Instability Induced By Low Chronic Oxidative Stress, Elisa Coluzzi, Rossella Buonsante, Stefano Leone, Anthony J. Asmar, Kelley L. Miller, Daniela Cimini, Antonella Sgura

Bioelectrics Publications

Cells are often subjected to the effect of reactive oxygen species (ROS) as a result of both intracellular metabolism and exposure to exogenous factors. ROS-dependent oxidative stress can induce 8-oxodG within the GGG triplet found in the G-rich human telomeric sequence (TTAGGG), making telomeres highly susceptible to ROS-induced oxidative damage. Telomeres are nucleoprotein complexes that protect the ends of linear chromosomes and their dysfunction is believed to affect a wide range of cellular and/or organismal processes. Acute oxidative stress was shown to affect telomere integrity, but how prolonged low level oxidative stress, which may be more physiologically relevant, affects telomeres …

Synaptotagmin C2b Ca2+-Binding Loops Impose Distinct Exocytosis Phenotypes, Michael W. Schmidtke

Wayne State University Theses

Regulated exocytosis from chromaffin cells in the adrenal medulla plays a critical role in maintaining organismal homeostasis. In the absence of stress, these cells release physiologically relevant substances into the blood stream only in limited quantities, whereas stressful conditions result in a rapid deluge of signaling molecules used, for example, to increase heart rate and pain tolerance. Although the cellular mechanisms governing the switch from low-level to stress-induced secretion are not well understood, recent evidence has implicated the exocytotic Ca2+-sensing protein Synaptotagmin (Syt) in this role.

Two isoforms of Syt are expressed in chromaffin cells (Syt-1 and Syt-7), and each …

Testing The Optomotor Response In Sepia Bandensis, Lauren E. Thompson

Honors College Theses

Cephalopods (octopus, squid, and cuttlefish) have commonly been used as models to test visual function and camouflage due to their similarity in eye morphology with humans and because of their readily observable changes in body color in response to visual stimuli. Most studies have used a single species, Sepia officinalis, to make broad conclusions about camouflage and vision. However, these generalizations may not be applicable to all species. Here, I have examined visual function of the dwarf cuttlefish (Sepia bandensis), which differs from S. officinalis in habitat, geographic range, and size. Using the optomotor response, I quantified …

The Effect Of Cold On The Physiology Of Drosophila Larva Heart And On Synaptic Transmission At Crayfish Neuromuscular Junctions, Yuechen Zhu

Theses and Dissertations--Biology

Ectothermic animals are susceptible to temperature changes such as cold shock with seasons. To survive through a cold shock, ectotherms have developed unique strategies. My interest is focusing on the physiological function of during cold shock and prolonged cold exposure in the fruit fly (Drosophila melanogaster) and crayfish (Procambarus clarkii). I used Drosophila melanogaster as a model system to investigate cardiac function in response to modulators (serotonin, acetylcholine, octopamine, dopamine and a cocktail of modulators) in acute cold shock and chronic cold shock conditions as possible mechanism to regulate heart rate in the cold. To examine if the dampened heart …

Influence Of Topography And Moisture And Nutrient Availability On Green Alder Function On The Low Arctic Tundra, Nt, Katherine Louise Black Ms., Jennifer Lynn Baltzer Dr.

Theses and Dissertations (Comprehensive)

The Arctic has warmed by at least 3^°C over the past 50 years and this rapid warming is expected to continue. Climate warming is driving the proliferation of shrubs across the tundra biome with implications for energy balance, climate, hydrology, nutrient cycling, and biodiversity. Changes in tundra plant water use attributable to shrub expansion are predicted to increase evapotranspirative water loss which may amplify local warming and reduce run-off. However, little is known about the extent to which shrubs will enhance evapotranspirative water loss in these systems. Direct measures of shrub water use are needed to accurately predict …

Examining The Combined Effects Of Dissolved Oxygen, Temperature, And Body Size On The Physiological Responses Of A Model Macrobenthic Polychaete Species, Capitella Teleta, Kelsey Burns Gillam

Dissertations

While the scientific community is in consensus that coastal systems are threatened by climate change, few climate change studies test the effects of more than one variable directly related to climate change. The dissolved oxygen (DO) levels of the ocean are currently subject to both global warming and eutrophication; 94% of all hypoxia zones are expected to experience >2°C increase by 2035. This dissertation aims to examine how a model organism responds to simultaneous thermal and DO stress involving four levels of DO (100%, 70%, 50%, and 20%) saturation and three temperatures (15°C, 20°C, and 25°C).

The polychaete, Capitella teleta …

The Elasmobranch-Microbe Relationship: Trimethylamine N-Oxide Synthesis, Urea Hydrolysis, And Microbe-Osmolyte Interactions In The Atlantic Stingray, Dasyatis Sabina, Kaitlin Kelly Doucette

Master's Theses

The elasmobranch osmoregulatory strategy is predicated on the accumulation of nitrogenous compounds, primarily urea and trimethylamine n¬-oxide (TMAO). Despite the abundance of these plasma osmolytes, it is notable that elasmobranchs appear to lack urease and TMA oxidase (Tmase), enzymes that scavenge urea-nitrogen and synthesize TMAO, respectively. However, urease and Tmase are found in many species of bacteria. Therefore, I hypothesized that intestinal bacteria are responsible for urease and Tmase activity in elasmobranchs. Absent dietary nitrogen sources, I evaluated the effects of reduced intestinal microbiota on osmoregulation in Atlantic stingray (Dasyatis sabina) in vivo. D. sabina were given …

Effect Of Oxygen-Limiting Tidal Conditions On Muscle Metabolism And Structure In The Giant Acorn Barnacle, Balanus Nubilus, Katie O. Grady

Master's Theses

Crustacean muscle fibers are some of the largest cells in the animal kingdom, with fiber diameters in the giant acorn barnacle (Balanus nubilus) exceeding 3 mm. Sessile animals with extreme muscle sizes and that live in the hypoxia-inducing intertidal zone – like B. nubilus – represent ideal models for probing the effects of oxygen limitation on muscle cells. We investigated changes in metabolism and structure of B. nubilus muscle in response to: normoxic immersion, anoxic immersion, or air emersion, for acute (6h) or chronic (6h exposures twice daily for 2wks) time periods. Following exposure, we immediately measured hemolymph …

Design Of Novel Ion Channel Modulators, Vladimir Yarov-Yarovoy

Science Seminar Series

Function and modulation of neuronal sodium channels are critical for the neuromodulation of electrical excitability and synaptic transmission in neurons - the basis for many aspects of signal transduction, learning, memory and physiological regulation. Mutations in neuronal voltage-gated sodium channel genes are responsible for various human neurological disorders. Furthermore, human neuronal voltage-gated sodium channels are primary targets of therapeutic drugs used as local anesthetics and for treatment of neurological and cardiac disorders. Yarov-Yarovoy's lab is working on rational design of novel therapeutically useful blockers of voltage-gated sodium channels for treatment of pain and epilepsy. Serious, chronic pain affects at least …

Understanding Adipocyte Dynamics Through Mathematical Modeling, Katrina Johnson, Fred Adler

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

Abiotic Factors Contributing To The Survival Of Three Tick Species In Southeastern Virginia, Amblyomma Americanum (Lone Star Tick), Dermacentor Variabilis (American Dog Tick), And Amblyomma Maculatum (Gulf Coast Tick), Lindsey A. Bidder

Biological Sciences Theses & Dissertations

Amblyomma americanum, Amblyomma maculatum, and Dermacentor variabilis are hard-bodied ticks in the Hampton Roads area of southeastern Virginia. This study consisted of two field projects focused on these tick species. To estimate the off-host survival of local tick species, a capture-mark-recapture (CMR) study was performed. An environmental survival study was performed to quantify the ability of these three tick species to survive in situ. Four field sites were used in the Hampton Roads region covering a variety of habitat types and vegetation; specifically two drier, upland field sites and two flood-prone sites. CMR was conducted from May through …

Sperm Morphometrics, Spermatogenesis, And Testicular Cycle Of The Rough Greensnake (Opheodrys Aestivus), John Douglas Konvalina

Student Theses and Dissertations

Spermatogenesis in ophidians is understudied, with little information on the rough greensnake, Opheodrys aestivus available. A cell wheel showing the chronological development of germ cell stages for this species was constructed. Sperm morphometrics were completed and compared with those of Nerodia rhombifer, the diamondback watersnake. Both species had similar sperm head length, while Opheodrys aestivus had significantly longer total sperm length. Total sperm length was positively correlated (r = 0.997, p < 0.001) with sperm tail length. Seminiferous tubule diameter and seminiferous tubule epithelial height were measured from Arkansas (AR) specimens and compared with those of Alabama (AL) specimens and AR measurements were found to be significantly greater in length. Future studies of O. aestivus need to investigate the testicular cycle in other parts of its geographic distribution to see if the monthly pattern is consistent and sperm morphometrics should be examined for other species within the family Colubridae.

Maternal Sleep Loss During Fetal Development Alters Offspring Endocrine Responses To Stress Throughout Life, Audrey Brown

Mahurin Honors College Capstone Experience/Thesis Projects

The hypothalamic-pituitary-adrenal (HPA) axis releases glucocorticoids, including corticosterone (CORT), in response to stress. CORT then negatively feeds back to inhibit its own production by binding to glucocorticoid receptors (GRs) in the hypothalamus and pituitary gland. The HPA axis is subject to “programming” by abnormal stimuli during early development, which may permanently alter how the HPA axis responds to stress. These altered responses have been linked to an increased risk for human psychiatric and metabolic disorders in later life, but the mechanism by which this happens is not fully understood. This study tests the hypothesis that changes to GR expression patterns …