Biology Commons^™

Characterization And Analysis Of The Avian Epidermal Differentiation Complex And Implications In Feather Evolution, Anthony Chastine Davis

Theses and Dissertations

Since the most recent major mass-extinction event ~65 million years ago, birds have expanded to now occupy a wide range of habitats and exhibit diverse lifestyles. A major reason for this evolutionary success is the mechanical resilience and diversity of their epidermal appendages such as feathers, scales, and beaks. The diversity of these appendages, specifically feathers has played a critical role in their evolutionary success. The feathers of birds vary substantially across different species, as well as at different life stages and anatomical locations on an individual bird. Several of the genetic elements involved in the development and structure of …

Using Genetic Diversity To Differentiate Mosquito Populations, Rachel Christine Malampy

Theses and Dissertations

Experiment 1: Little is known about Aedes aegypti females sharing oviposition sites. We examined four different oviposition sites in McAllen, TX. A mitochondrial gene was used to analyze the variation within the oviposition site to understand how many egg-laying females are sharing oviposition sites. These results will aid in the understanding of Aedes. aegypti oviposition behavior and contribute to more effective mosquito control techniques.

Experiment 2: Mosquito flight patterns and movement from habitat to habitat can drastically influence the spread of diseases. The anthropophilic Aedes aegypti mosquito has historically been identified as having a very limited flight range. Studies also …

Proteomics Of The Egg Cell Membrane Of The Sea Star Patiria Miniata, Emily Wiseman

Theses and Dissertations

The conception of life, the creation of a genetically distinct being, is an event that has fascinated humanity for ages. It was only recently, at the turn of the 20th century, that the field of reproduction research reached an age of molecular mechanics, and with that, an onslaught of difficulties were encountered. The egg is a unique cell type because it contains a number of mRNA transcripts that do not express proteins necessary for the initial moments of gamete interaction or egg activation. Instead, these RNAs are stored in the egg for expression during early embryonic development. Coupled with the …

Elucidating The Role Of The High Aliphatic Glucosinolate ( Hag ) Genes In Pennycress ( Thlaspi Arvense L. ) Glucosinolate Production, Dalton Williams

Theses and Dissertations

Pennycress (Thlaspi arvense L.) is a Brassica species being developed into an oilseed-producing winter cash cover crop. Similar to its relatives, rapeseed (Brassica napus L.) and camelina (Camelina sativa L.), pennycress seeds produce high levels of oil and protein (~34% oil and ~19% protein dry weight). For pennycress to be economically viable and environmentally sustainable as a crop, both the oil and seed meal must be utilized. Pennycress like other Brassicaceae, produces high levels of glucosinolates in the seed coat. Glucosinolates taste bitter and can be metabolized by the enzyme, myrosinase, into toxic isothiocyanates, nitriles, and epithionitriles. Seed meal containing …

Pvt1 Exon 9 A Regulator Of Claudin Expression In Triple Negative Breast Cancer, Fayola Levine

Theses and Dissertations

Claudin low triple negative breast cancer (TNBC) has the worst clinical outcomes in comparison to other breast cancer subtypes. The underlying molecular mechanisms associated with the aberrant expression of claudins are not well understood. The transcript from PVT1 exon 9 is a regulator of claudin expression, and migration, in TNBC.

Cytotoxic Analysis Of Old Drugs: New Drugs For Alzheimer’S Disease, Sebastian Yumiseba

Theses and Dissertations

Microglia are the resident immune cells of the CNS and constitute about 10% of all cells in the CNS. They have a vital role in Alzheimer’s pathogenesis as either cytotoxic or neuroprotective. Recent efforts are being put into repurposing drugs to target the microglia to treat Alzheimer’s disease.

Laying-Sequence Variation In Yolk Carotenoids Of Eastern Bluebirds, Jessica Barkhouse

Theses and Dissertations

Carotenoids are naturally occurring, fat-soluble pigments that play an important role in the embryonic development of songbirds. Female songbirds use different strategies to allocate these important maternal resources to their eggs. Little research has been done on whether North American songbirds exhibit laying sequence patterns in their allocation of carotenoids. We studied the laying-sequence variation in yolk carotenoids and egg metrics of nine full clutches of Eastern Bluebirds (Sialia sialis) in Columbus, Georgia. I predicted that Eastern Bluebirds would exhibit a brood reduction strategy, with the first-laid eggs containing a higher concentration of carotenoids than the last-laid eggs. …

Estimating Taxonomic Diversity Using Centrum Growth Profiles And Stinger Morphology Of 36 Million Year Old Stingrays From North Dakota, Persia S. Tillman

Theses and Dissertations

Stingrays are a diverse and popular group of vertebrates; however, nothing is known about the relationships between growth biology and climate change. Freshwater stingrays once inhabit the United States and Canada during very warm times in the geologic record. No stingray material has been recorded from the northern part of the United States for the last 33 million years. The Earth’s climate cooled from 50 to 33 million year ago when many warm adapted organisms were relegated to warmer, southern latitudes in North America. Today, freshwater stingrays only inhabit subtropical and tropical environments. We are interested in the freshwater stingrays …

Earliest Known Material Of Amia, Bowfin, From The Sentinel Butte Formation (Paleocene), Medora, North Dakota, Abby Grace Moore

Theses and Dissertations

Amia calva is an icon in the field of comparative osteology, yet we have a poor understanding of the evolution of the genus because many fossil amiid bones have gone unidentified. Here we identify new material of the genus, Amia, with evidence of two unidentified species. Previously, the oldest known material identifiable as Amia cf. A. pattersoni, was a specimen from the Paleocene epoch of Alberta, Canada approximately 58 million years in age. Fossils of the two unidentified species of Amia were found in the Sentinel Butte Formation, a geologic formation of Paleocene age (~ 60 million years …

Exploring Interactions Of Phyllosphere Epiphytes With Plant Pathogenic Bacteria Pseudomonas And Xanthomonas On Tomato, Ashley D. Turner

Theses and Dissertations

Recent studies have indicated the importance of resident microflora of plants in contributing towards overall plant health. Among difference components of the plant microbiome, Methylobacterium and Sphingomonas have been recognized as common residents of the phyllosphere for many host plants, however their role in disease control needs to be further investigated. The purpose of this study was to conduct experiments investigating the effectiveness of phyllosphere Methylobacterium and Sphingomonas isolated from red clover against common tomato phyllosphere bacterial pathogens, Pseudomonas syringae pv. tomato and Xanthomonas perforans. Additionally, this study uses X. perforans wild-type and X. perforans type VI secretion system …

Comparing Novel And Traditional Sampling Methodologies To Analyze The Population Status Of The Rio Grande Cooter (Pseudemys Gorzugi), Amy P. Bogolin

Theses and Dissertations

The Rio Grande Cooter, Pseudemys gorzugi, is an understudied aquatic turtle species of conservation concern in the Rio Grande, Pecos, and Devils river systems. Traditional sampling methodologies for aquatic turtle species face numerous challenges, but novel sampling methodologies, such as drone-based surveys and environmental DNA analysis, may address these issues. This study compared novel sampling methodologies to traditional sampling methodologies in mean detections and identifications of aquatic turtle species, developed and implemented an environmental DNA assay to detect P. gorzugi, and characterized P. gorzugi habitat. Following an introductory chapter, each task is addressed by chapter and formatted to …

Lipid Analysis, Fluorescence Microscopy And Flow Cytometry As Tools To Evaluate Microalgae For Potential Biofuel Production, Giovanina Aimee Hinojosa

Theses and Dissertations

Petroleum-based crude oil is nonrenewable and toxic to the environment, leading to a need for a more efficient and environmentally effective replacement. Microalgae produce lipids which can be converted to recyclable biofuels; therefore, research in lipid production by algae is becoming important for an economic and environmental sustainability. Microalgae can re-absorb atmospheric CO2 and have rapid growth, thereby lowering greenhouse gasses (GHGs) emission, renewability, and simple growth requirements.

Nannochloris sp. is a marine microalga that is amenable for lipid production because there is little research on it so this study will focus on using flow cytometry, fluorescence microscopy and other …

The Effects Of Salvia Hispanica On Biochemical Markers Related To Immune System, Hormone Regulation, And Lumbar Vertebrae In Postmenopausal Rat Model, Daisy M. Mendez

Theses and Dissertations

In women, with age and menopause there is increase in body weight and decreased immunity and bone mass. Due to severe side effects of currently available drugs for obesity and bone loss, new therapies with less side effects are sought after and alternative medications are becoming more popular. Recently, Salvia hispanica (SH), a herbal supplement is implicated in losing body weight. Currently, there is no information on how SH modulates obesity or bone health. In this study, effects of SH seed extract was investigated in a postmenopausal rat model on certain hormones, immune markers, and fourth lumbar vertebrae. The highest …

Organizational Effects Of Exogenous Corticosterone On Vocal Development In A Wild Parrot, Rory Eggleston

Theses and Dissertations

Songbirds learn songs during a plastic phase in vocal development, similar to human vocal babbling. Research has focused on male song learning, a process influenced by gonadal steroids. Like humans, parrots are very plastic vocal learners and both sexes learn vocalizations throughout life. It is unclear how the endocrine system mediates environmental information with developing phenotypes in parrots. Corticosterone (CORT) is a sex-neutral hormone that can affect cognitive development, but its role in vocal development has not been experimentally tested in wild parrots. I quantified vocal babbling from nestling Green-rumped Parrotlets (Forpus passerinus) recorded in Venezuela. Nestlings received oral CORT-oil …

Effects Of Arbuscular Mycorrhizal Fungi (Amf) On Growth And Herbivore Defenses In Sorghum Sudangrass (Sorghum X Drummondii), Jasleen Kaur

Theses and Dissertations

Chapter 2: In this chapter we have examined the role of trichomes in plant stress biology, reviewed the studies on herbivore X trichome interactions, and their role in plant defences. Ultimately, we have proposed new areas of research for future work.

Chapter 3: In this chapter, we examined whether AMF has cascading effects on insect community dynamics through attraction/repulsion of beneficial and damaging insects using Sorghum-sudangrass (Sorghum x drummondii), either inoculated with commercial AMF mix or left as control in lab and field experiments. Our results suggest positive effects of AMF on plant growth, and a lower initial incidence of …

Characteristics And Spatial Heterogeneity Of Prescribed Fire Behavior In North Dakota Grasslands, Megan Elizabeth Zopfi

Theses and Dissertations

Fire is a critical physical and chemical process required to sustain many grassland ecosystems. In North America, observations of grassland fire behavior in warm-season, southern grasslands are commonly used in fire behavior modeling efforts across the Great Plains. However, grasslands of the northern Great Plains contain a greater component of cool-season vegetation that may generate different fire behavior. To further our understanding of prescribed fire behavior in North Dakota grasslands, we quantified fuel, weather, and fire behavior characteristics associated with 27 prescribed fires conducted across three sites in North Dakota. We sampled 27 points on each fire arranged into a …

Investigating The Localization Of Foxo Transcription Factors In Glioblastoma, Leetoria Hinojosa

Theses and Dissertations

The Phosphatidylinositol 3 Kinase (PI3K) pathway is an essential intracellular signaling pathway that regulates cellular growth, survival, and fate. Canonically, the activation of this pathway removes forkhead box subfamily O transcription factors (FOXO -1, -3, and -4) from the nucleus. However, in cancer cells such as glioblastoma multiforme, FOXO factors are at least in part nuclear despite the activation of the PI3K pathway. Previous research indicated that FOXO3 localization was not affected when the pathway was inhibited in breast cancer cells, which challenged the conventional paradigms for FOXO factor regulation. Therefore, we were interested in investigating the nuclear localization of …

Symbiosis And Immunity At The Tri-Kingdom Interface, Stephen Alexander Lazar

Theses and Dissertations

The rise in global sea-surface temperatures drastically and adversely impacts coral reefs worldwide through coral bleaching, diseases, and subsequent coral mortality. Corals become bleached by the expulsion of endo-symbiotic dinoflagellates, which reduces host pigmentation. Coral bleaching can also lead to enhanced disease prevalence immediately after thermal-stress and during the associated re-uptake of symbiotic dinoflagellates. This aspect has yet to be thoroughly investigated. A model system is necessary to study the relationships between symbiosis and disease that has sufficient flexibility to include a variety of host symbionts as well as pathogens. For this dissertation project, Exaiptasia pallida was investigated as a …

Megafaunal Extinction In The Neotropics: A Landscape Approach, Angela Rozas Davila

Theses and Dissertations

A 20 million years reign of large terrestrial mammals, known as megafauna (animals over 45 kg), came to an end during the Pleistocene-Holocene transition. Particularly apparent in the Americas, the sudden extinction of Pleistocene megafauna has no equivalent in the fossil record as it only targeted large terrestrial animals. Early hypotheses explaining this extinction focused on climatic forcing and anthropogenic interactions, which included extensive hunting and/or landscape transformation. More recently, a third plausible explanation of megafaunal extinction has been the combined effects of climate-change and human influences; commonly referred to as the ‘synergistic effect of climate-humans’ hypothesis. The study of …

Identifying And Characterizing Transgenic Lines That Drive Gene Expression In The Adult Fat Body Of The Drosophila Melanogaster, Michael Edward Meyerink

Theses and Dissertations

Adult Drosophila Melanogaster is a powerful model organism in genetic studies and has high tissue and gene homology to humans. Like humans, Drosophila tissues communicate in order to respond to physiological stimuli, such as diet, aging, and disease. The fat body, homologous to human adipocytes and hepatocytes, functions as both an endocrine and energy storage organ; and has been shown to play a critical role in many metabolic processes. The aim of this study is to characterize differences in fat body gene expression to ultimately identify if there are subpopulations of adipocytes with different functions related to fat body communication …

Natural Product Berbamine Enhances The Efficacy Of Doxorubicin Treatment For Triple Negative Breast Cancer, Jake Tyler

Theses and Dissertations

According to breast cancer statistics, 279,100 new cases are expected in the United States in 2020 (Siegel et al., 2020). Triple negative breast cancer (TNBC) is the most aggressive subtype of breast cancer with a significantly shorter median overall survival compared to other subtypes of breast cancer. Unlike hormone-positive or HER2-positve breast cancers with effective hormonal or targeted therapies available, there has been very little clinical success from targeted therapies for TNBC. Doxorubicin (Dox) is one of the most used chemotherapy drugs. The only limitation of Dox treatment is its cytotoxicity. Berbamine dihydrochloride (BBM) is a natural benzylisoquinoline alkaloid that …

Morphological Changes In The Visual Sensory System Of Congeneric Fishes Inhabiting Clear And Turbid Aquatic Environments, Habeeb Mohsin Hammadi Alsudani

Theses and Dissertations

This study examined the histological aspects of the visual system of six species of fish. Menidia extensa and Fundulus waccamensis are found in Lake Waccamaw, which is a unique aquatic environment of the Atlantic coastal plain characterized by low turbidity, higher pH and clarity. Menidia beryllina, Menidia menidia, Fundulus diaphanus and Fundulus heteroclitus are found in the Waccamaw River, which is characterized by high turbidity. These species have undergone morphological changes likely related to inhabiting two ecological systems that differ in their environmental characteristics. We tested the hypothesis that fish modify their visual system to adapt to various environments.

The …

Reconsidering Undergraduate Anatomy And Physiology Curriculum, Eric Michael Walsh

Theses and Dissertations

In the past 50 years several convergent factors have spurred unprecedented change in anatomy and physiology (A&P) instruction. An explosion of biomedical knowledge, an increased demand for students well-versed in A&P, and decreased resources for the course has provoked a vast array of research. However, most studies employ one of three strategies to enact change: testing the effectiveness of new pedagogies, exploring the utility of new technologies, or documenting learning in new contexts. By comparison, a much smaller body of research focuses on changing the A&P curriculum to improve student learning. To address this gap, the musculoskeletal curriculum for an …

Investigating The Patterns And Mechanisms Of Alternative Splicing Of Cav1.3 In The Mouse., Samuel Sabzanov

Theses and Dissertations

AL-type voltage-gated calcium channel Cav1.3 contains a pore-forming α-1 subunit that is encoded by Cacna1d, a gene which has been shown to undergo alternative splicing (AS). Mutations in CACNA1D have been associated with neurological diseases such as spontaneous seizure disorder and epilepsy. Previous studies have shown that AS of the C-terminus of Cav1.3 results in a truncated variant of exon 42 (E42) that, when compared to the full-length exon, lowers the voltage threshold needed to activate the calcium channel. Therefore, AS of the a1-subunit can modulate the physiological properties of Cav1.3. As a lower voltage threshold of calcium channels increases …

Bioenergetic Modulation Of Retinal Progenitor Cell Glycolysis To Drive Invasion For Photoreceptor Replacement, Jei Espinal

Theses and Dissertations

Given the limited regenerative capacity of the mammalian retina, cell-replacement strategies are necessary. To replace photoreceptors lost to disease or trauma and restore visual function, laboratories throughout the world are researching photoreceptors replacement strategies using subretinal transplantation of retinal progenitor cells (RPCs). A major obstacle to the advancement of photoreceptor cell-replacement strategies includes low rates of invasion and integration of transplanted cells into the host retina. Currently, there is a limited understanding of how RPC glycolysis may facilitate invasion. To further understand RPC glycolysis-driven invasion, the current investigation involved the bioenergetic modulation RPCs for glycolysis analysis and invasion modeling. The …

Sinorhizobium Meliloti Changes Motility Phenotypes In The Presence Of Serum, Eris K. Bisal

Theses and Dissertations

Sinorhizobium meliloti is a nitrogen-fixing flagellated soil bacterium that engages in a mutual symbiotic relationship with the legume Medicago sativa. Using its flagella, S. meliloti is chemotactic in response to varying environmental cues thereby directed to a target, which is typically the root hairs of M. sativa. Lu et al, 2012 suggested that a signal from the plant can switch S. meliloti from a free-living flagellated microbe to a host-invading non-flagellated microbe, although this signal has not been identified. This switch is thought to occur inside curled root hairs of the plant, and after becoming non-flagellated, S. …

Synaptic Plasticity In A Visual Cortical Region Induced By Early-Deafness, John M. Kay

Theses and Dissertations

When organisms learn and adapt to their environment or lose a sensory modality, neurons in the brain undergo a cellular process called ‘plasticity.’ This thesis explores the loss of a non- visual system (early deafness) and how it can affect visual plasticity. To examine this question, Golgi-stained cortical neurons were studied from the visual region PLLS from early-deaf cats and their hearing controls. Dendritic spine density and dendritic spine diameter are well-known indicators of synaptic plasticity and these neuronal features were measured using light microscopic techniques and Neurolucida. Within the visual PLLS, the mean spine density for the deaf cats …

The Functional Importance Of Methyl Cpg Binding Domain Proteins 2 And 3 In Regulating Fetal Hemoglobin Expression In Human Adult Erythroid Cells, Alexander Azzo

Theses and Dissertations

Humans undergo two developmental switches in the predominantly expressed β-like globin chain during embryogenesis and fetal development. The first switch from embryonic (ε) to fetal (γ) occurs around week 5 of embryonic development, while the second switch from fetal to adult (β) globin occurs shortly after birth. By adulthood, fetal hemoglobin represents only 1-2% of total hemoglobin in the blood. As sufficiently elevated levels of fetal hemoglobin are beneficial for improving clinical outcomes in sickle cell disease and β-thalassemia, the mechanisms that enforce silencing of fetal hemoglobin expression postnatally are of great clinical significance. The methyl-CpG binding domain protein MBD2 …

The Influence Of Breeding Density On Female Aggression, Parental Care, And Ornamentation In A Secondary-Cavity Nesting Warbler, Elsa B. Chen

Theses and Dissertations

Tradeoffs between individual survival and reproductive success associated with aggressive behaviors are a driving force of evolution, but these tradeoffs are often overlooked for aggressive conspecific interactions between females. For avian males, it is well documented that more aggressive individuals tend to provide less parental care. In the few studies that address this in females, the tradeoffs seem to be more context-dependent, varying due to factors such as predation pressure and habitat quality. The relationship between female ornamentation and aggression is similarly understudied, but evidence suggests that both aggression and ornamentation are important traits involved in social selection – the …

A Study On The Mechanism Of Clp290 Restoration Of Kcc2 And Neuroprotection After Traumatic Brain Injury, Ekaterina Stepanova

Theses and Dissertations

The research of this thesis investigated the mechanism of action for the therapeutic compound CLP290, which our laboratory has previously demonstrated to reverse degradation of the protein potassium-chloride co-transporter 2 (KCC2) and restore neuronal function following modeled traumatic brain injury (TBI) in the rat. The loss of membranous KCC2 from the plasma membrane after TBI worsens the excitation/inhibition imbalance common in neurotrauma. Addressed here were the specific aims to: 1) assess that CLP290 treatment restores the functional oligomeric form of KCC2 to the neuronal plasma membrane as necessary to provide chloride homeostasis; 2) investigate the signaling mechanism by which CLP290 …