Life Sciences Commons^™

The Y-Chromosome's Role In Sexually Dimorphic Evolution And Mother's Curse Compensation, Tobias Nielsen

Electronic Theses and Dissertations, 2020-

The Y-chromosome and mitochondria (containing mtDNA) appear entirely dissimilar, the former being a sex chromosome found in the nucleus and the latter an organelle with thousands of copies in the cytoplasm. However, both experience uniparental inheritance, with Y-chromosomes being patrilineal and mitochondria matrilineal. This leads to various other similarities including haploidy, high mutation rates, and limited or lack of genetic recombination. Moreover, the low number of protein-coding genes contained on both led to the belief that neither contributes significantly to the adaptive evolution of complex traits. However, recent studies show the Y-chromosome and mitochondria both influence roughly 10% of male …

Investigating Biometrics Of Perimyotis Subflavus In Traditional And Nontraditional Hibernacula In The Southeastern United States As It Relates To Susceptibility To White-Nose Syndrome., Makayla Ferrari

Master of Science in Integrative Biology Theses

Perimyotis subflavus, or tricolored bat, populations have declined significantly since the emergence of white-nose syndrome (WNS) and has been proposed for listing as “endangered” under the United States Endangered Species Act. Traditionally, bats use caves as hibernacula, but as anthropogenic impacts have increased so has the use of manmade structures like culverts and bridges for roosting by several bat species. The internal environment of these anthropogenic structures is influenced by external temperature and humidity differently than caves and may influence P. subflavus winter activity, and thus susceptibility to WNS. One of the most significant differences in P. subflavus roosting behavior …

Caribbean Reef-Building Coral-Symbiodiniaceae Network: Identifying Symbioses Critical For System Stability In A Changing Climate, Shaman Patel

All HCAS Student Capstones, Theses, and Dissertations

Increasing global ocean temperatures and frequency of marine heatwaves pose dire consequences for coral reefs. High temperatures often lead to disruptions in coral symbiosis resulting in coral bleaching, increasing the mortality of corals. However, corals can potentially avoid bleaching peril by associating with thermally tolerant symbionts. Here we provide a tool for understanding symbiosis network stability of Caribbean reef-building corals. We created a network of Caribbean hermatypic corals and their associated Symbiodiniaceae phylotypes. A bleaching model was applied to this network to test for resilience and robustness (R50) to thermal stress. It was also layered with trait data for coral …

Environmental Sensitivity Of Maternal And Offspring Phenotype In The Green Anole (Anolis Carolinensis) Lizard, Jamie Marks

University of New Orleans Theses and Dissertations

Animals dynamically invest their acquired energetic resources into fitness-related traits, and life-history trade-offs occur when limited resources are invested in a given trait at the expense of another. The phenotypic effects of life history trade-offs are well documented, but the mechanisms facilitating these trade-offs are poorly understood. One such mechanism is the insulin/insulin-like signaling (IIS) network, and specifically its two primary hormones: insulin-like growth factor 1 (IGF1) and insulin-like growth factor 2 (IGF2). IGF1 is well-characterized but IGF2 is severely understudied, though it is present in nearly all amniotes and sometimes expressed at higher levels than IGF1 in adulthood. I …

Ankyrin Dependent Mitochondrial Function And Bioenergetics In The Heart, Janani Subramaniam, Janani Subramaniam

Dissertations & Theses (Open Access)

ANK2 mutations in patients are associated with numerous arrhythmias, cardiomyopathies, and other heart defects. In the heart, AnkB, the protein encoded by ANK2, clusters relevant ion channels and cell adhesion molecules in several important domains; however, its role at Mitochondria Associated ER/SR Membranes (MAMs) has yet to be investigated. MAMs are crucial to mitochondrial function and metabolism and are signaling hubs implicated in various cardiac pathologies. Among several functions, these sites mediate the direct transfer of calcium from the ER/SR to the mitochondria to modulate ATP synthesis. Given that mitochondrial function and energy production are paramount to cardiovascular heath, …

Importance Of The Microhabitat And Microclimate Conditions In The Northern Gray-Cheeked Salamander (Plethodon Montanus) Across An Elevation Gradient, Trevor Chapman

Electronic Theses and Dissertations

The southern Appalachian Mountains have among the highest salamander diversity in the world, largely due to local speciation in the family Plethodontidae. Plethodontid salamanders (i.e., lungless salamanders) are particularly sensitive to habitat climate conditions due to their reliance on cutaneous respiration, and their immediate environmental conditions (microhabitat) likely influence their dispersion and activity more than the large-scale atmospheric conditions. The Northern Gray-cheeked salamander (Plethodon montanus) is restricted to high elevations in the Appalachian Mountains. Our goal was to investigate the relationship between P. montanus and its microhabitat by examining behavioral preference for climatic conditions, characterizing the microclimate with …

Venomic Characterization Of A Medically Relevant Rear-Fanged Snake, Conophis Lineatus (Dipsadidae: Xenodontinae), From Middle America, Tristan Schramer

All Theses

Most traditional research on snake venoms has focused on front-fanged snake families (Viperidae, Elapidae, and Atractaspididae). However, venom is now generally accepted as being a much more broadly possessed trait within snakes, including species traditionally considered harmless. Unfortunately, due to historical inertia and methodological challenges, the toxin repertoires of non-front-fanged snake families (e.g., Colubridae, Dipsadidae, and Natricidae) have been heavily neglected despite the knowledge of numerous species capable of inflicting medically relevant envenomations. Integrating proteomic data for validation, we perform a de novo assembly and analysis of the Duvernoy’s venom gland transcriptome of the Central American Road Guarder (Dipsadidae: Xenodontinae: …

Influence Of Plant Density On Rainfall Interception By Spartina Alterniflora, Hannah K. Longaberger

Honors College Theses

Abstract

Spartina alterniflora is an abundant plant in eastern US and Gulf coast salt marshes; it is important in maintaining a diverse ecosystem. Salt marshes are impacted by rainstorms, which may affect erosion events. This project examined the partitioning of rainfall on single plants of various sizes and on central plants within different canopy densities of S. alterniflora. By calculating the rain stemflow (SF), throughfall (TF), and water adhered to the stem in S. alterniflora, we gained insight to rainfall partitioning with different plant features. My research found no statistically significant relationship between different plant features and SF, TF, …

Larval Fish Export In Response To Varying Compensating Gate Discharge At The Sault Rapids, St. Marys River, Signe F.K. Vandrunen

All NMU Master's Theses

The St. Marys River (SMR) forms the border between Michigan, USA and Ontario, Canada connecting lakes Superior and Huron. Discharge is controlled by a compensating gate system upstream of the SMR rapids. Because spring and summer discharge fluctuates widely, resource managers required information on how flow variability influences larval fish drift. I estimated annual larval fish export in relation to variable discharge during 2018-2021 and compared results to published habitat model predictions. Mean discharge and water temperature were lowest in 2021 and highest in 2019. Water warming rates during high discharge differed from low discharge trends. Across years, I identified …

Constraints Of The Imagination: How Phenotypes Are Shaped Through Genetics, The Environment, And Development, Michelle Gilbert

Doctoral Dissertations

Phenotypic constraints are ubiquitous throughout nature, being found throughout all stages of life and at multiple different biological levels including cellular, genetic, environmental, behavioral, evolutionary, and developmental. These constraints have shaped, not only the natural world, but the way that we perceive what is possible, or impossible, an observation made clear by François Jacob in his 1977 paper “Evolution and Tinkering”. This is reflected in the literature, repeatedly, by the regular occurrence of densely packed visualization of phenotypic space that seemingly always have large areas that go unoccupied. Despite constrained regions of space being observable across countless taxa, identifying the …

Effects Of Mass Death On Community Structure And Ecosystem Function, Abby Kimpton Jones

Theses and Dissertations

Death and decomposition are natural processes that are generally well-understood. However, large events of death, such as mass mortality events (MMEs) are increasing in frequency and their impacts on the ecosystem are largely unknown. These events may have both bottom-up effects from increased nutrient input as well as top-down effects from loss of an ecological functional group by the affected population. Different functional MMEs may result in different top-down effects, creating cascading effects. In Chapter 1, I test the hypothesis that scavenger and herbivore simulated MMEs generate novel bottom-up and top-down effects. Results indicate that MMEs have a significant effect …

Chemically Induced Phytoextraction Of Lead (Pb) Contaminated Soil By Switchgrass (Panicum Virgatum L.), Assisted With Bap And Nta Applications, Genna Hart

Master of Science in Integrative Biology Theses

The accumulation of lead (Pb) deposits in soil is a growing global concern. Phytoextraction of Pb-contaminated soil can be enhanced by soil chelation to increase the bioavailability of Pb. In the initial study nitrilotriacetic acid (NTA) 5mM, the alkylpolyglucoside (APG) Triton X-100 (2%), and nano-silica were applied to switchgrass (Panicum virgatum L.) growing in 5L pots of Pb-contaminated soil. The second experiment used 10mM NTA, the alkylpolyglycoside Triton X-100 (2%), foliar application of the plant growth regulator 6-benzylaminopurine (BAP) twice per week, Triple-12® nutrients, and Infuse™ a soil fungicide which were applied to switchgrass Plants were grown in a controlled …

Heavy Metal Distribution Across Three Georgia Estuaries Using Coastal Sharks As Sentinel Species, Allyson Stiles

Master of Science in Integrative Biology Theses

Estuaries are transitional environments that play key roles in coastal ecosystem functioning by providing essential habitats to ecologically important plant and animal species. Estuaries are exposed to a number of anthropogenic impacts, including heavy metal contamination from human activities. However, few studies have examined heavy metal distribution within Georgia’s estuaries and how intact salt marsh ecosystems could play a role in filtering and sequestering contaminants, such as Mercury (Hg). This thesis examined blood total mercury (THg) concentrations of four coastal shark species and concentrations of five heavy metals (Hg, As, Cr, Cu, and Pb) within the water and sediments of …

The Effects On Soil Fungal Community Of Excluding Select Above-Ground Herbaceous Species In A Montane Longleaf Pine Savanna Restoration Area, Sean Davis

Master of Science in Integrative Biology Theses

Due to anthropogenic pressures, by the 1990s longleaf pine forests were at 3% its peak area. Restoration is difficult as vegetation communities constitute a mosaic across the longleaf range. Hence, vegetation description is important wherever longleaf pine communities exist. Vegetation strongly associates with specific soil fungi operational taxonomic units (OTUs) and description of longleaf pine ecosystems are incomplete without description of microbial taxa.

My goals were to begin describing soil fungal communities of the longleaf pine at Sheffield Wildlife Management Area (SWMA) and describe changes to the fungal community after the removal of dominant plants in a longleaf savanna. I …

Assessing The Indigenous Arbuscular Mycorrhizal Fungi (Amf) Community Associated With Sea Oats Along The Georgia Coast At Jekyll And Tybee Islands, Kylie Stover

Master of Science in Integrative Biology Theses

Coastal sand dunes are fragile ecosystems that serve as natural defenses to protect the adjacent mainland by absorbing the impacts and energy from severe storms. Different efforts have been taken to restore coastal sand dunes, focusing on foredunes. However, there are many strategies involved with coastal restoration and one superior technique has not been found to be the best. Arbuscular mycorrhizal fungi (AMF) supply a range of limiting nutrients (N, P, Fe, and Zn) to the host plant while improving dune stability. This study aimed to assess and compare the diversity of the indigenous AMF community associated with sea oats …

What I Talk About When I Talk About Integration Of Single-Cell Data, Yang Xu

Doctoral Dissertations

Over the past decade, single-cell technologies evolved from profiling hundreds of cells to millions of cells, and emerged from a single modality of data to cover multiple views at single-cell resolution, including genome, epigenome, transcriptome, and so on. With advance of these single-cell technologies, the booming of multimodal single-cell data creates a valuable resource for us to understand cellular heterogeneity and molecular mechanism at a comprehensive level. However, the large-scale multimodal single-cell data also presents a huge computational challenge for insightful integrative analysis. Here, I will lay out problems in data integration that single-cell research community is interested in and …

Regional-Scale Climate-Induced Variation In Ant Physiology And Morphology, Daniel E. Murphy

Biology Theses

The biology of ectotherms such as insects is influenced by ambient thermal conditions. Ants are a ubiquitous and ecologically important group of insects and are well-established as bioindicators of thermal conditions. Ants are sensitive to the thermal extremes that vary with latitude, elevation, and land use, and these thermal gradients influence their spatial and temporal distributions. As a result, ants have evolved physiological and morphological thermal adaptations in response to the thermal environment of their habitats. These adaptations include increased physiological and morphological tolerance for temperature extremes. In Western New York (WNY), temperatures are temporally and spatially heterogeneous, changing with …

Chromosome Number Evolution, Phylogeography, And The Effects Of Climate Change On Species Distributions In Polyploid Plant Systems, Courtney H. Babin

University of New Orleans Theses and Dissertations

Polyploidy, a term used to describe organisms with cells having more than two paired sets of chromosomes, is a significant driver of diversification among land plants. Over a century of research has advanced our understanding of polyploidization in some taxa, but polyploid organisms remain understudied. In this dissertation, I investigate chromosome number evolution, phylogeographic structure, genetic differentiation, and the effects of climate change on ploidy level distribution using polyploid plant systems. In the first chapter, I inferred a molecular phylogeny of Allium, an economically important genus that includes cultivated crops and ornamentals, to investigate evolutionary transitions in chromosome number …

Evaluating The Impact Of Intersecting Research And Outreach Marine Science Programs On Elementary And Undergraduate Students, Randi J. Sims

All Theses

Climate change is one of the most destructive forces our ocean is currently experiencing. Despite this, many students are not taught the basics of climate change science and ocean literacy in public school systems. My work seeks to combat these deficits through educational experiences in marine science for undergraduate and local elementary students through three studies incorporating marine-science based research and outreach. (1) Through undergraduate marine science research and outreach, students enrolled for long durations or with positive mentorship increased their conceptual understanding of marine science concepts, altered their attitudes towards climate change and science, and were more likely to …

Non-Photic Mechanisms Of Entrainment In Bmal1 Deficient Conditions, Jamie Tran

Dissertations & Theses (Open Access)

Maintaining our internal circadian (i.e. 24 -hour) clock is imperative to our daily biological and mental well-being. Large epidemiological studies have shown that disruptions of our circadian rhythms can lead to poor mental health, metabolic diseases, and various types of cancer. Various external cues that have become a part of the modern times such as electricity, shift -work, rapid travel across various time zones, easier access to nutritionally unbalanced food items, and various rigid social demands have deleterious effects on our internal clock, and generally reduce robustness of the circadian clock. The two following projects aim to examine two fundamental …

Patterns Of Evolutionary Conservation And Divergence In The Short-Term Hyposalinity Stress Response Of A Euryhaline Diatom, Skeletonema Marinoi, Kathryn Judy

Graduate Theses and Dissertations

Survival under fluctuating environmental conditions, such as those increasing in frequency and magnitude under environmental change, requires a successful response to stress. Interspecific differences in stress responses may result in differential survival of species, even within a lineage. Diatoms may constitute one such lineage, as salinity tolerance among extant species is diverse, and the observation of frequent historic habitat transitions between marine and freshwater environments indicates that diatoms successfully mitigated (low) salinity stress in the past, followed by adaptation and diversification over evolutionary time scales. To understand to what extent the diatom hypoosmotic stress response consists of conserved and variable …

Haplotype-Informed Allelic Imbalance Detection From Rna In Cancer, Zuhal Ozcan

Dissertations & Theses (Open Access)

Comprehensive genomic and transcriptomic characterization of tumors has uncovered enrichment for distinct aneuploidy and expression patterns, demonstrating the utility of molecular based classification of cancers and their subtypes. Existing cohorts with transcriptomic profiling from next-generation sequencing contain an untapped potential to also relate genomics with rich clinical phenotypes. Yet, derivation of somatic copy number and expression profiles from analyses of RNA has remained elusive. Further, DNA analysis in these cohorts is not always feasible due to limited tissue availability or financial constraints. Here, we present a statistical approach that overcomes these challenges using haplotype information to aid detection of somatic …

Connecting Above- And Belowground Effects Of Climate Warming On Bumble Bee Health, Francis Mullan

Master of Science in Integrative Biology Theses

Climate warming has been identified as one of the primary factors causing worldwide pollinator declines. One of the most at-risk groups of pollinators is bumble bees (Bombus spp.). Bumble bees are common, widespread, and key pollinators of a wide range of crops and wild plants. Although studies have examined the thermal physiological traits of individual bumble bees to understand how they may be impacted by climate warming, little to no studies have examined how climate warming may impact whole bumble bee colonies both in their ability to thermoregulate their nest for their brood or in their ability to forage …

Ant Cuticle Microsculpture: Diversity, Classification, Evolution, And Function, John Paul Hellenbrand

Master of Science in Integrative Biology Theses

My thesis covers the intricacies of ant microsculpture diversity, classification, evolution and function. To do this, the thesis is organized into two chapters. The first chapter is a review of ant cuticle and microsculpture diversity as well as including analyses examining the evolution and lability of microsculpture traits. I then review the literature for functional hypotheses related to ant microsculpture. The second chapter explores the relationship of microsculpture and important morphological, physiological, and ecological traits to evaluate support for functional hypotheses.

The Evolution Of Honeycomb, Grace Cope

Master of Science in Integrative Biology Theses

The regular cells of honeycomb nests have fascinated scholars and mathematicians for millennia. In 36BC, the Roman scholar Marcus Terentius Varro first proposed the “honeycomb conjecture,” in which he postulated that bees build their comb using hexagons because it is the shape that requires the least amount of material to divide space into equal portions. Since this time, honeycomb has been used by engineers in applications that range from skyscraper supports to impact absorbers inside the feet of the lunar lander during the first moon missions, but mysteries remain about the biological origins of honeycomb and the mechanical properties of …

The Effect Of Breathing Patterns Common To Competitive Swimming On Gas Exchange And Muscle Deoxygenation During Heavy-Intensity Fartlek Exercise, Kevin J. Grossman

Electronic Thesis and Dissertation Repository

The purpose of this study was to compare the respiratory and muscle deoxygenation (HHb) responses of regulated breathing versus free-breathing, during continuous exercise (CONLD) and intermittent 5s breath holds (BH) (CONLD-BH), intermittent 5s sprint (FLK) and combined 5s BH and sprint (FLK-BH) followed by 25s of free-breathing. Oxygen uptake(V̇O₂)was unchanged between CONLD (2.12±0.35L/min) and CONLD-BH (2.15±0.42L/min; p=0.116), and FLK (2.24±0.40L/min) and FLK-BH (2.20±0.45L/min; p=0.861). Δ[Hb_tot]: CONLD (3.3±1.6µM) > CONLD-BH (-2.5±1.2µM; ∆177%; p<0.001), but unchanged between FLK (2.0±1.6µM) and FLK-BH (0.82±1.4µM; p=0.979). Δ[HHb]: CONLD (7.3±1.8µM) > CONLD-BH (7.0±2.0µM; ∆4%; p=0.011), and FLK (6.7±1.8µM) < FLK-BH (8.7±2.4µM; p<0.001). It is suggested that the unchanged V̇O₂ between CONLD and CONLD-BH was supported by increased deoxygenation, reflected by decreased ∆[Hb_tot] and blunted …

Studying Tissue Specific Diversity Of Splicing Regulator Muscleblind, Davron Hanley

Master of Science in Integrative Biology Theses

The muscleblind (mbl) family of RNA-binding proteins regulates alternative splicing, determining mRNA transcript composition for various types of tissue, and has been implicated in myotonic dystrophy. The mbl gene is subject to alternative splicing in Drosophila, leading to multiple isoforms, and has several paralogs in humans. Mbl proteins vary significantly in length, although the significance of such diversity and the role of specific isoforms have not been fully explored. Using immunofluorescence microscopy and polyclonal serum, we analyzed Mbl protein expression across adult Drosophila tissues. Mbl was detected in various locations, including the brain, gonads, muscle, and gut epithelium. Skeletal muscles …

Sodium Mediates Developmentally Plastic Responses In Plants And Herbivores, Luis Santiago-Rosario

LSU Doctoral Dissertations

Sodium plays a crucial role in organismal performance, trophic-level interactions, and eco-evolutionary dynamics. For plants, sodium impacts osmoregulation, growth, and water uptake. For animals, sodium is essential influencing osmoregulatory processes, muscle and neural development, and blood regulation. My dissertation aims to disentangle why sodium mismatch affects resource-consumer interactions and its influence on morphological and behavioral plasticity. First, I identified how sodium impacts plant performance and sodium accumulation strategies. I initially focused my research on understanding how increasing substrate sodium affects plant growth and tissue sodium accumulation strategies in controlled settings using a systematic review approach. I found that saltier plants …

A Review Of Current Methods In Avian Dietary Analysis And Their Integrated Application To Characterize The Trophic Niche Of Louisiana Waterthrush (Parkesia Motacilla)., Brandon Hoenig

Electronic Theses and Dissertations

Characterizing a species’ dietary composition presents an avenue to understand many facets of its ecological niche and can provide essential information for the species’ long-term conservation. To date, the vast majority of diet studies have relied on direct identification of prey during foraging observations or from diet samples to characterize the dietary habits of birds. However, advancements in laboratory-based approaches have revolutionized the field of trophic ecology by allowing researchers to indirectly infer dietary habits with higher resolution across greater time scales. Here, I apply two of these laboratory-based techniques, namely DNA metabarcoding and stable isotope analysis, to characterize the …

Physiological Costs Of Total Cholesterol In European Starlings Across An Urban To Rural Gradient, Courtney Linkous

Master of Science in Integrative Biology Theses

Urban areas—characterized by high human densities and associated buildings and impermeable surfaces—are increasing globally and represents a leading threat to wildlife that is drastically altering the natural resources they are accustomed to. Prior studies suggest that living in urban habitats can cause wildlife to show increased cholesterol levels; in biomedical research, elevated cholesterol is linked to disease, but the consequence of elevated cholesterol in wildlife remains unclear. We measured total cholesterol in European starlings (Sturnus vulgaris)—an urban adapted species—across an urban and a rural site. We ask: (1) do urban starlings have elevated cholesterol, (2) does elevated cholesterol …