Biology Commons^™

Roles Of Peroxisomes And Peroxisome-Derived Products In Controlling Plant Growth And Stress Responses, Elizabeth May Frick

Arts & Sciences Graduate Student Theses and Dissertations

The peroxisome is a vital organelle conserved through the entire eukaryotic lineage. In all examined species, peroxisomes are responsible for such essential processes as fatty acid beta-oxidation and metabolism of reactive oxygen species (ROS). In plants, peroxisomes have taken on additional specialized roles, such as production of some plant hormones and vitamins. In this work, I have uncovered novel factors regulating peroxisome number in model species Arabidopsis thaliana, and novel mechanisms governing how peroxisomes respond to salt stress. I discovered a role for Arabidopsis MAP KINASE17 (MPK17) as a negative regulator of peroxisome division that acts in the salt-stress response …

A Generalized Biophysical Model Of Transcription Factor Binding Specificity And Its Application On High-Throughput Selex Data, Shuxiang Ruan

Arts & Sciences Graduate Student Theses and Dissertations

The interaction between transcription factors (TFs) and DNA plays an important role in gene expression regulation. In the past, experiments on protein–DNA interactions could only identify a handful of sequences that a TF binds with high affinities. In recent years, several high-throughput experimental techniques, such as high-throughput SELEX (HT-SELEX), protein-binding microarrays (PBMs) and ChIP-seq, have been developed to estimate the relative binding affinities of large numbers of DNA sequences both in vitro and in vivo. The large volume of data generated by these techniques proved to be a challenge and prompted the development of novel motif discovery algorithms. These algorithms …

Longitudinal Cerebrospinal Fluid Biomarkers Of Alzheimer Disease: Movement Toward The Diagnosis, Prognosis And Staging Of Disease, Courtney Sutphen

Arts & Sciences Graduate Student Theses and Dissertations

Alzheimer’s disease (AD) is a devastating neurodegenerative disease that slowly claims the memories and experiences that comprise the life experiences of individuals that suffer from the disease. Despite a continually accelerating pace of research and discovery, a viable therapeutic intervention for AD has yet to be realized. There are a multitude of factors that may contribute to this difficulty including the challenge of separating the overall disease of Alzheimer’s from the clinically recognizable memory loss that occurs in what is now known to be the end-stage of the disease. Efforts to treat AD have increasingly turned toward very early disease …

Regulation Of Gene Expression By Rna Binding Proteins And Micrornas, Kyle Cottrell

Arts & Sciences Graduate Student Theses and Dissertations

Regulation of gene expression is essential to life. Post-transcriptional regulation of gene expression is a complex process with many inputs that lead to changes in localization, translation and stability of mRNAs. The translation and stability of many mRNAs is regulated by cis-elements, such as mRNA-structure or codon optimality; and by trans-acting factors such as RBPs and miRNAs. Here I report on the complex interactions between RBPs, miRNAs and characteristics of their target mRNAs in respect to effects on translation and RNA stability.Using a reporter based approach we studied modulation of microRNA-mediated repression by various mRNA characteristics. We observed the influence …

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 …

Role Of Transforming Growth Factor (Tgf) – Β Signaling In Craniofacial Development, Malignancies And Regeneration, Jingpeng Liu

Theses & Dissertations

The transforming growth factor (TGF) – β signaling pathway regulates a diversity of fundamental cellular processes such as cell growth and proliferation, cell differentiation, migration, apoptosis and other biological functions, both during embryogenesis and in adult tissue homeostasis. TGF-β is known to play a critical role in palatal development as in TGF-β knockout murine models, TGF-β deficiency causes cleft palate, a common craniofacial deformity in humans due to the abnormality of growth, elevation or fusion of the two palatal shelves. In order to investigate the mechanisms of how TGF-β regulates palatogenesis, we generated TGF-β3 knockout (-/-) murine models, performed systematic …

Influenza A Virus Genomic Reassortment And Packaging, Graham Devin Williams

Arts & Sciences Graduate Student Theses and Dissertations

Influenza A viruses (IAV) are a major human and environmental pathogen. IAV successfully infects a diverse host range and adaptation of new viral strains to humans may cause pandemic events with high morbidity and mortality. As a member of the Orthomyxoviridae family, IAV inherently possesses a segmented genome, which enables a process of segment transmission between viruses following cellular co-infection, a process termed reassortment. The high rate of IAV mutation and continued co-circulation of diverse viral strains in divergent host species leads to the persistent prospect for emergence of new IAV with pandemic potential. Therefore, it is of great importance …

Mechanism Of Gene Regulation By Coding Polya Tracks, Laura Lea Arthur

Arts & Sciences Graduate Student Theses and Dissertations

Regulation of gene expression is essential for cellular development and survival. The great variety and complexity of regulatory mechanisms underscores this fact. Messenger RNA stability and translational efficiency are often key determinants of gene expression. mRNA surveillance pathways, discovered for their role in degradation of aberrant mRNA, are now known to be instrumental in the regulation of physiologically correct mRNA stability. Thus, the study of cis elements in a transcript that can induce mRNA surveillance pathways has become an area of particular interest.Here I report on the mechanism of gene regulation by coding polyA tracks, defined as a sequence of …

The Regulation Of Extracellular Amyloid-Β Levels By Ionotropic Glutamatergic Transmission In An Alzheimer’S Disease Mouse Model, Jane Cecelia Hettinger

Arts & Sciences Graduate Student Theses and Dissertations

Brain extracellular concentration of the peptide amyloid-β (Aβ) is a major contributor to Alzheimer’s disease (AD) pathogenesis. High Aβ levels in the extracellular space precipitate aggregation of the peptide into soluble and insoluble toxic species. This process begins decades before cognitive impairment and triggers the cascade of pathology that eventually leads to AD. Synaptic activity is key to the regulation of extracellular Aβ levels. Presynaptic activity drives the production of Aβ, while postsynaptic receptor activation exhibits more nuanced regulation. For example, high levels of NMDA receptor (NMDA-R) activation have been shown to decrease Aβ production through the extracellular signal-regulated kinase …

Bridging The Translational Gap Between Rodent And Human Pain Research, Tayler Diane Sheahan

Arts & Sciences Graduate Student Theses and Dissertations

The treatment of chronic pain is an immense clinical and societal burden rooted in the ineffectiveness and adverse side effects of existing analgesics. Extensive efforts have been directed towards the development of novel pain therapies with maximal efficacy and minimal unwanted effects; however, putative therapeutic targets identified in preclinical rodent models rarely translate in clinical trials. The poor translational record of basic pain research findings has been attributed, in part, to the use of suboptimal rodent pain models and behavioral endpoints used to assess putative analgesics, as well as differences in the pharmacological profiles of rodents and humans. The work …

Regulation Of Early Zebrafish Embryogenesis By Calcium Signaling And Dachsous1b Cadherin, Jiakun Chen

Arts & Sciences Graduate Student Theses and Dissertations

Early animal embryogenesis entails a dynamic combination of embryonic cleavages, axial patterning, and gastrulation movements to shape a basic body plan. The underlying molecular signaling responsible for regulating this process remains poorly understood. In this thesis work, I first review recent progress in understanding of gastrulation movements in various model organisms brought by advances in imaging techniques. The externally developing and optically translucent zebrafish embryo is an ideal model organism to study vertebrate embryonic development by in vivo imaging. The objective of my thesis research is to leverage experimental advantages in the zebrafish model to uncover novel regulators and elucidate …

Analysis Of Argonaute-Small Rna-Transcription Factor Circuits Controlling Leaf Development, John Steen Hoyer

Arts & Sciences Graduate Student Theses and Dissertations

Experimental studies of plant development have yielded many insights into gene regulation, revealing interactions between core transcriptional and post-transcriptional regulatory pathways present in all land plants. This work describes a direct connection between the three main small RNA-transcription factor circuits controlling leaf shape dynamics in the reference plant Arabidopsis thaliana. We used a high-throughput yeast 1-hybrid platform to identify factors directly binding the promoter of the highly specialized ARGONAUTE7 silencing factor. Two groups of developmentally significant microRNA-targeted transcription factors were the clearest hits from these screens, but transgenic complementation analysis indicated that their binding sites make only a small contribution …

Mutational Analysis Of The Molluscum Contagiosum Virus Mc160 Protein, Henri Estanbouli

Seton Hall University Dissertations and Theses (ETDs)

The Molluscum Contagiosum Virus (MCV), belongs to a family of large DNA viruses called Poxviridae. MCV causes a common skin infection resulting in benign neoplasms. 122 million cases of MC were reported in 2010. The virus is not primarily lethal, though fatalities have occurred due to secondary bacterial infections. Even with the high volume of reported cases, MCV is very much understudied, and its pathogenicity is not well understood. Thus, with that in mind, a more in-depth understanding of the MCV-host interactions is a priority. Presumably during infection, MCV utilizes immune evasion molecules to inhibit activation of the host pro-inflammatory …

Comparison Of Bacterial And Archaeal Communities In The Subsurface Versus Surface: Implications For Nitrogen Cycling, Jason Cody Kimble 5059801155

Biology ETDs

Arid-land caves are thought to be extremely nitrogen-limited, but almost nothing is known about how microbes in subsurface arid-land environments obtain this essential element to meet cellular demand. The depth of caves beneath the surface may represent a critical factor affecting microbial nitrogen cycling in these environments. Percolation of water and nutrients from a precipitation pulse event would affect deep arid-land carbonate caves at a much slower rate. To obtain nitrogen in deep, carbonate caves, microorganisms could use fixed N in the host rock for assimilatory biochemical pathways or for a respiratory electron acceptor. However, the latter process leads to …

Vertebrate Body Size Jumps The Wright Way, Peter J. Wagner

School of Biological Sciences: Faculty Publications

Fossil data provide copious evidence that anatomical (morphological) change within individual lineages is not constant: short bursts of great change commonly separate long durations of little change (1, 2). Despite this, most models of morphological change assume that probabilities of morphological character change are the same from one generation to the next: even if rates change over time—such as in “Cambrian explosion” or “early burst” models, where high disparity among anatomies evolves early—then it is still assumed that fast rates of continuous character change gave way to slow rates of continuous change (3). In statistical parlance, early bursts usually are …

The Role Of Orphan Nuclear Receptor Dax-1 (Nr0b1) In Human Breast Cancer Cells: Expression, Proliferation And Metastasis, Erin Dishington

Master's Theses

The orphan nuclear hormone receptor DAX-1 (Dosage Sensitive Sex Reversal, Adrenal Hypoplasia Congenita on the X Chromosome, gene 1) plays an important role in the development of adrenal and gonadal tissues and functions as a global negative-regulator of steroidogenesis. In addition, it is known to be involved in several diseases including some cancers. Herein, we describe our examination of the role of DAX-1 in breast cancer, specifically its influence on proliferation and metastasis and its expression during progressive stages of disease. In an effort to understand how DAX-1 influences breast cancer cell proliferation and metastasis, we used MCF7 breast cancer …

Nitrogen Addition And Ecosystem Functioning: Both Species Abundances And Traits Alter Community Structure And Function, Anna R. Tatarko, Johannes M.H. Knops

School of Biological Sciences: Faculty Publications

Increased nutrient inputs can cause shifts in plant community composition and plant functional traits, both of which affect ecosystem function. We studied community- and species-level leaf functional trait changes in a full factorial nitrogen (N), phosphorus (P), and potassium (K) fertilization experiment in a semi-arid grassland. Nitrogen was the only nutrient addition to significantly affect leaf functional traits, and N addition increased community-weighted specific leaf area (SLA) by 19%, leaf chlorophyll content by 34%, height by 26%, and leaf dry matter content (LDMC) decreased by 11% while leaf thickness and toughness did not change significantly. At the species level, most …

Nanostructured Apatite-Mullite Glass-Ceramics For Enhanced Primary Human Osteoblast Cell Response, Gordon Cooke, Conor Dunne, Sarah Keane, Daithi De Faoite, Seamas Donnelly, Kenneth Stanton

Articles

This work investigates the difference in viability of primary human foetal osteoblast cells on a glass-ceramic surface with nanoscale topography relative to viability on a smooth glass-ceramic surface containing a bioactive phase. Apatite-mullite glass-ceramics containing bioactive fluorapatite (Ca₁₀(PO₄)₆F₂) and bioinert mullite (Si₂Al₆O₁₃) were synthesised and subsequent heat-treatment was optimised to form nano-sized fluorapatite crystals. Etching was used to selectively remove the bioactive phase, producing a surface with disordered nanoscale topography. Cells were seeded onto a smooth polished glass-ceramic substrate with the bioactive phase intact, an etched …

Using Mixed Effects Modeling To Quantify Difference Between Patient Groups With Diabetic Foot Ulcers, Rachel French

Mahurin Honors College Capstone Experience/Thesis Projects

When diabetes progresses, many patients suffer from chronic foot ulcers. In a study described in Matrix Metalloproteinases and Diabetic Foot Ulcers (Muller et al., 2008), sixteen patients with diabetic foot ulcers were examined throughout a twelve week healing period. During this period, levels of matrix metalloproteinases (MMP-1), their inhibitors (TIMP-1), and the extracellular matrix in a wound area were measured at distinct time intervals for each patient. The ratios of these healing components are vital in determining whether a wound will heal or become chronic and never properly heal. Connecting Local and Global Sensitivities in a Mathematical Model for Wound …

Editorial: Murine Models Of Leukemia And Lymphoma, Christine E. Cutucache, Pierluigi Porcu

Biology Faculty Publications

Murine models serve as an effective way to mimic the in vivo tumor microenvironmental interactions that take place in patients with leukemias and lymphomas. Specifically, leukemias and lymphomas rely heavily on the surrounding stroma and tissue microenvironmental cytokine and chemokine signals to ensure survival and expansion of tumor cells. Finally, leukemic cells migrate thanks to signals from varying regions of the host, furthering the progression and severity of disease. It is therefore impossible to fully understand such a dynamic relationship between tumor cells and their surrounding microenvironment, and the events to transformation in leukemias and lymphomas without an in vivo, …

Genetic Analysis Of The Major Capsid Protein Of The Archaeal Fusellovirus Ssv1: Mutational Flexibility And Conformational Change, Eric A. Iverson, David A. Goodman, Madeline E. Gorchels, Kenneth M. Stedman

Biology Faculty Publications and Presentations

Viruses with spindle or lemon-shaped virions are rare in the world of viruses, but are common in viruses of archaeal extremophiles, possibly due to the extreme conditions in which they thrive. However, the structural and genetic basis for the unique spindle shape is unknown. The best-studied spindle-shaped virus, Sulfolobus Spindle-shaped Virus 1 (SSV1), is composed mostly of the major capsid protein VP1. Similar to many other viruses, proteolytic cleavage of VP1 is thought to be critical for virion formation. Unlike half of the genes in SSV1, including the minor capsid protein gene VP3, the VP1 gene does not tolerate …

American Society Of Parasitologists Newsletter, Volume 39, Number 2, Fall/ Winter, 2017, Scott L. Gardner

American Society of Parasitologists: Newsletter

Fall/Winter 2017 issue of the ASP newsletter.

Insights Into The Molecular Roles Of Zika Virus In Human Reproductive Complications And Congenital Neuropathologies, Rajendra Ghardbaran, Latchman Somenarain

Publications and Research

The recent upsurge in the association of congenital neurological disorders and infection by the Zika virus (ZIKV) has resulted in increased research focus on the biology of this flavivirus. Studies in animal models indicate that ZIKV can breach the placental barrier and selectively infect and deplete neuroprogenitor cells (NPCs) of the developing fetus, resulting in changes of brain structures, reminiscent of human microcephaly. In vitro and ex vivo studies using human cells and tissues showed that human NPCs and placental cells are targeted by ZIKV. Also of concern is the impact of ZIKV on human reproductive structures, with the potential …

Analysis Of Heart Muscle Tissue For Detection Of Fluorescently Labeled Cells In Conventional- And Frozen-Section Tissue Preparations, Lena Anna Mitchell

Honors Theses

No abstract provided.

Forage Selection And Habitat Architecture As Drivers Of Small Mammal Community Dynamics In An Arid, Nutrient Limited, Highly Stochastic Ecosystem, Jennifer Darby Noble

Biology ETDs

In the Northern Chihuahuan desert, grassland and shrubland co-occur as separate stable states under similar climatic conditions. In this bottom up (resource driven) system, the magnitude and timing of precipitation events drives primary production which varies from year to year and season to season. Climate change is predicted to alter precipitation regimes, and increase aridity, facilitating shrub encroachment which results in increased landscape heterogeneity and a decrease in plant biodiversity. These changes will likely result in a restructuring of small mammal communities.

We used long-term data on precipitation, primary production, and abundances of small mammals in adjacent grassland and shrubland …

Developmental Nonlinearity Drives Phenotypic Robustness, Rebecca M. Green, Jennifer L. Fish, Nathan M. Young, Francis J. Smith, Benjamin Roberts, Katie Dolan, Irene Choi, Courtney L. Leach, Paul Gordon, James M. Cheverud, Charles C. Roseman, Trevor J. Williams, Ralph S. Marcucio, Benedikt Hallgrímsson

Biology: Faculty Publications and Other Works

Robustness to perturbation is a fundamental feature of complex organisms. Mutations are the raw material for evolution, yet robustness to their effects is required for species survival. The mechanisms that produce robustness are poorly understood. Nonlinearities are a ubiquitous feature of development that may link variation in development to phenotypic robustness. Here, we manipulate the gene dosage of a signaling molecule, Fgf8, a critical regulator of vertebrate development. We demonstrate that variation in Fgf8 expression has a nonlinear relationship to phenotypic variation, predicting levels of robustness among genotypes. Differences in robustness are not due to gene expression variance or …

A Redescription Of The Ichnospecies Koreanaornis Anhuiensis (Aves) From The Lower Cretaceous Qiuzhuang Formation At Mingguang City, Anhui Province, China, Li-Da Xing, Yuan-Chao Hu, Jian-Dong Huang, Qing He, Martin G. Lockley, Michael E. Burns, Jun Fang

Research, Publications & Creative Work

The Cretaceous bird trackway originally labeled Aquatilavipes anhuiensis, in 1994, had previously been examined, photographed and replicated, but never described or illustrated in detail. However, it has been part of a widening discussion about the distribution of Aquatilavipes and Koreanaornis in China (and Korea). Here we illustrate and formally describe the holotype in detail and assign it to Koreanaornis (Koreanaornis anhuiensis) as informally proposed by previous authors. We also demonstrate that most authenticated reports of Koreanaornis, including the Anhui occurrence, are from the Lower Cretaceous, not from the Upper Cretaceous as previously reported.

A Teachable Unit On Soft Corals With Instructional Method Variances, Emily Breech

Honors Projects

The soft coral Sinularia flexibilis contains an aqueous alcohol extract that has shown antineoplastic activity against lymphocytic leukemia (Weinheimer and Matson, 1977). It also has other biological properties that work as antimicrobials, anti-inflammatory agents, and cytotoxicity activities (Kamel and Slattery, 2005). There is much research on the effects of flow rate on growth and morphology (Khalesi, Beeftink, & Wijffels, 2007) and the effects of light-dependency on growth rate (Khalesi, Beeftink, & Wijffels, 2009). The purpose of this student project was to further research on S. flexibilis, as well as incorporate that research into evaluating the effects of lecture-based teaching …

Inhibitory Or Excitatory? Optogenetic Interrogation Of The Functional Roles Of Gabaergic Interneurons In Epileptogenesis, Hui Ye

Biology: Faculty Publications and Other Works

Alteration in the excitatory/inhibitory neuronal balance is believed to be the underlying mechanism of epileptogenesis. Based on this theory, GABAergic interneurons are regarded as the primary inhibitory neurons, whose failure of action permits hyperactivity in the epileptic circuitry. As a consequence, optogenetic excitation of GABAergic interneurons is widely used for seizure suppression. However, recent evidence argues for the context-dependent, possibly “excitatory” roles that GABAergic cells play in epileptic circuitry. We reviewed current optogenetic approaches that target the “inhibitory” roles of GABAergic interneurons for seizure control. We also reviewed interesting evidence that supports the “excitatory” roles of GABAergic interneurons in epileptogenesis. …

Comparison Of Photosynthesis Among Three Chaparral Species In The Family Anacardiaceae, Catelyn T. Price, Sarah A. Holmes, Brandon T. Harris, Stephen D. Davis, Karagan L. Smith, Talia A. Cao

Featured Research

Recent argumentative data showed a lack of niche differentiation amongst three Banksia species in Australia conducted by Lamont and Bergl, and the Anacardiaceae family in the native chaparral of the Santa Monica Mountains are supposed to be significantly similar¹. Because of this we wanted to test if there would be a significant difference between the stomatal conductance, photosynthesis, and water potential in samples of the Rhus ovata, Rhus integrifolia, and Malosma laurina (Rhus laurina) species. We tested this idea by collecting the stomatal conductance and photosynthetic rates of each plant species in the same general location with …