Biology Commons^™

Rapid Radiation Of Zeiformes Revealed Through Comparison Of Jaw Morphologies, Jeffrey Peters

Master's Theses

Zeiformes (e.g., Dories, Lookdown dories, Tinselfishes, Oreos) are a deep (1000 m) to mid-water (100 m) marine order of acanthomorph fishes with a circumpolar distribution, and a fossil record extending back to the Late Cretaceous. The order consists of 33 species across six families. The phylogenetic placement of the Zeiformes within Teleostei has been debated, but more recent studies based on both molecular and morphological data place Zeiforms within Paracanthopterygii closely related to Gadiformes. Zeiformes are characterized by anal and dorsal profiles that contain a variable number of fin rays and spines. They are mostly deep bodied, highly compressed fishes …

A Comparison Of Impa2 & Isyna1 Gene Expression And Intracelular Myo-Inositol Levels In Bipolar And Non-Bipolar Disorder Derived Human Lymphoblasts, Christina Rosette

Master's Theses

The thesis objective was to determine if myo-inositol concentration levels and the gene expression of IMPA2 & ISYNA1 differ among bipolar disorder types 1 and 2 compared to healthy controls (non-bipolar disorder). Previous studies have correlated different myo-inositol concentration levels with specific phases of bipolar and pharmaceutical treatments. Two genes, inositol monophosphatase 2 (IMPA2) and inositol-3-phosphate synthase 1 (ISYNA1), involved in de novo myo-inositol biosynthesis have been implicated in the pathophysiology of bipolar. In this study, differences in myo-inositol concentration and IMPA2 & ISYNA1 gene expression in lymphoblasts derived from subjects with bipolar types 1, 2, and healthy control were …

Temozolomide-Nsaid Mixtures And Novel Diclofenac-Purine Hybrids As Potential Antiglioblastoma Agents, Joshua Rotich

Master's Theses

Glioblastoma (GBM) is the most common, lethal and aggressive brain tumor in adults. Standard treatment involves surgery, radiation therapy and temozolomide (TMZ) chemotherapy. However, GBM recurs and the average survival rate is between 12 to 18 months with 25% 1-year survival rate and 9% 5 years survival rate. Treatment options and advancement is limited by the blood brain barrier (BBB) which restricts drug entry into the brain and the immense heterogeneity of the tumor which limit adequate control of the entire tumor using one drug. In this research, we explored whether a combination mixture of TMZ and non-steroidal anti-inflammatory drugs …

Peruvian Mammals Collected By The Andrews University. Department Of Biology : Expeditions & Patterns Of Diversity, Kieran M. Taylor

Master's Theses

The Department of Biology at Andrews University conducted three expeditions to Peru in 1964, 1965, and 1968. During the expeditions, thousands of specimens were collected of several taxa, including mammals. As far as we know, no complete summary of the expeditions and the mammals collected has been created. Knowledge of the expeditions and evaluation of the mammals collected compared to current literature could have conservation implications. My purpose was to recreate the story of the expeditions and use this contextual information to catalog and identify the number of mammal species collected and evaluate the mammal diversity collected according to current …

Elucidating The Function Of An Evolutionarily Conserved Col2Α1 Isoform During Vertebrate Development, Charles Lantz H. Ingersoll

Master's Theses

ABSTRACT

Formation of skeletal structural elements during vertebrate embryogenesis is largely a

conserved evolutionary process that employs numerous conserved genes and pathways. One

critical gene in this process is the highly conserved vertebrate Type II Collagen alpha 1 (col2α1).

It produces multiple splice isoforms that have different functions and expression patterns during

skeletogenesis. Two of the primary isoforms are of great interest; variant 1, the primary

embryonic isoform, and variant 2, a post embryonic isoform. While the more commonly known

post-embryonic isoform has been well studied over the last 30 years, identification of a unique

role for the evolutionarily conserved …

Development And Characterization Of A Tissue-Specific Reporter Line For Monitoring Circadian Clock Transcriptional Activity, Lilyan Mather

Master's Theses

Daily rhythms in physiology and behavior are produced by a circadian system consisting of a central clock located in the brain and peripheral clocks located in various peripheral tissues. Circadian clocks track time of day through the presence of a molecular clock that functions as a transcriptional-translational feedback loop. In the nucleus, the transcription factors CLOCK (CLK) and CYCLE (CYC) activate transcription of clock genes period (per) and timeless (tim). PER and TIM proteins slowly accumulate in the cytoplasm before entering the nucleus, where they inhibit CLK and CYC, and therefore repress their own transcription. Degradation of nuclear PER and …

Comparison Of Feeding Functional Morphology Development In North American Esocids, Cheryl Theile

Master's Theses

Esocidae is a family of freshwater fishes within order Esociformes known for its long, cylindrical bodies, duck-bill snouts, and an impressive number of sharp teeth. There are four species, including two subspecies, in North America with areas of overlap of their geographic distribution. These ambush predators change diets from invertebrate prey to vertebrate prey during their first year of life, and the timing of this shift varies between species. In particular, the sister species Esox lucius (Northern Pike) and Esox masquinongy (Muskellunge) overlap in the upper Midwest, but E. masquinongy transitions to a vertebrate diet sooner in its development than …

Biofilms On Plastic Litter: Community Composition And Activity And The Effects On Ecosystem Processes, Raul F. Lazcano

Master's Theses

The rapid increase of plastic production and disposal has resulted in plastic pollution becoming a global problem. In aquatic ecosystems, plastic litter is a substrate for biofilms, but little research has simultaneously assessed the effects of plastic litter on biofilm activity, community composition, and ecosystem processes. Our objectives were to: (1) measure biofilm activity and community composition on plastic litter relative to a natural surface in an urban river and (2) assess the impact of microplastic pollution on ecosystem metabolism and N2 flux in an oligotrophic lake. For objective (1) we incubated three common plastics with distinct physical and chemical …

Examination Of Methylation Status And Occupancy Of Dna Methylation Modifying Proteins On Regulatory Regions Of The Dax-1 Gene, Caroline P. Riedstra

Master's Theses

Epigenetic modifications influence gene expression and thereby play a pivotal role in development and disease. Misregulation and mutations in the DAX-1 gene, or Dosage-Sensitive Sex Reversal, Adrenal Hypoplasia Congenita, Critical Region on the X chromosome, gene 1, have been implicated in Adrenal Hypoplasia Congenita (AHC) and Dosage Sensitive Sex Reversal (DSS). The orphan nuclear hormone receptor DAX-1 is expressed predominantly in tissues such as the testes, ovaries, breast, adrenal cortex, and lung. Critically, DAX-1 may serve as an indicator of aberrant growth in these tissues. Here we hypothesize that DAX-1 is epigenetically regulated, specifically in cancer cells, thereby reducing its …

Spatial And Seasonal Patterns Of Above- And Belowground Vegetation Biomass And Potential Drivers In The Pascagoula River Delta, Ms, Evan Grimes

Master's Theses

Coastal wetlands provide a valuable wealth of services to the greater coastal ecosystem and human communities. However, threats such as sea level rise and conservation projects, such as freshwater diversions, have the potential to alter coastal wetlands in different ways. In this thesis, I describe the effects of inundation and nitrogen on vegetation productivity using a field-sampling approach and an in situ controlled mesocosm experiment, called a marsh organ. The West Channel of the Pascagoula River contained significantly higher belowground biomass than the East Channel, which is more anthropogenically modified. Vertical distribution of belowground biomass did not strongly vary between …

The Role Of Med31 And Med12 In Directing Adipogenesis Of Human Adult-Derived Mesenchymal Stem Cells, Joseph Straub

Master's Theses

Selective gene expression is crucial in maintaining the self-renewing and multipotent properties of stem cells. Mediator is a large, evolutionarily conserved, multisubunit protein complex that modulates gene expression by relaying signals from cell type-specific transcription factors to RNA polymerase II. In humans, this complex consists of 30 subunits arranged in four modules: head, middle, tail, and kinase. In our introduction, we show the state of the field of Mediator study with a focus on the critical kinase module. In the following chapters, we used siRNA knockdowns to investigate the roles of the highly-conserved core subunit MED31 and the kinase module …

Notch And Mediator Work Together To Direct Hasc Self-Renewal, Jaylen Mumphrey

Master's Theses

Stem cells are unique in that they possess totipotent, pluripotent, or multipotent differentiation capabilities and can also self-renew. Stem cells are in either a state of selfrenewal or differentiation, but never both. If we are able to gain a full understanding of the underlying mechanisms that allow stem cells to remain self-renewing and multipotent, we will better be able to control the fate of cells, ultimately allowing stem cells to be used to their full capabilities in regenerative medicine. My research focuses on MED12 and its effects on Notch signaling. Here we describe the expression profile and activity of MED12, …

The Role Of Med12 In Adipogenesis Of Human Adipose Stem Cells, Onyekachi Chinelo Idigo

Master's Theses

The interest in adipogenesis stems from the high rate of obesity in the world and the motivation to better understand the process of cell fate in relation to human diseases. Mutations in MED12 lead to developmental disorders and certain malignancies. To date, specific roles of Mediator and MED12 in cell state regulation are unclear, nevertheless, they are critical for understanding stem cell regulation and enhancement of their clinical applications. This study investigates the role of MED12 in relation to the Mediator complex kinase domain to better understand transcriptional control of adipogenesis in hASCs. In this study, MED12 expression was diminished …

The Role Of Med12 In Adipogenesis, Caroline Helen Rinderle

Master's Theses

In order for any function to occur within a cell, transcription factors must be able to interact with genes. When this occurs, genes are expressed, and ultimately, proteins are translated and perform the specific function that needs to be done within the cell. In order for this to occur, genes must interact with transcription machinery. The Mediator complex recruits transcription factors to genes in order to promote cell-type specific gene expression. The Mediator complex is a multi-protein complex consisting of four modules: head, middle, tail, and kinase. The kinase module is known to dissociate from the rest of the complex …

Investigating The Function Of Carboxypeptidase O Gene Paralogs From Xenopus Tropicalis, Ritchie Saint Jean

Master's Theses

Carboxypeptidase O (CPO) is a peptidase that is a member of the A/B subfamily of the metallocarboxypeptidases. This peptidase has been found in the brush border of the intestine and has specificity toward C-terminal acidic residues. CPO has been proposed to be involved in intestinal digestion and the formation of lipid droplets. Four copies of the CPO gene are present in the Xenopus tropicalis (tropical clawed frog) genome and are noted as CPO.1, CPO.2, CPO.3, and CPO.4. Not much is known about these genes regarding their properties and functions. In my research, I sought to investigate the properties and functions …

The Evolutionary And Morphological Diversification Of The Subtribe Papionina, Sophie B. Labelle

Master's Theses

Analysis of variation is critical in understanding evolutionary processes. The subtribe Papionina, defined commonly as baboons and their closest relatives, is a highly morphologically diverse group of primates that is useful for the examination of the relationship between variation and evolution. The subtribe is also a valuable behavioral, ecological, and morphological analogy for hominins. This study uses landmark-based cranial geometric morphometric data and multivariate analysis to test whether the pattern of morphological diversification present in Papionina is consistent with genetic drift and/or selection. The study sample consists of six extant genera of Papionin, represented by ~500 individuals collected by Michelle …

A Role For Notch Signaling In Drosophila Spermatogenesis, Adrianna Soriano

Master's Theses

The Notch signaling pathway has diverse functions in male and female gonad development. In Drosophila male embryos, Notch specifies hub cell fate in somatic gonadal precursor cells (SGPs), which are important for maintaining germline stem cells and somatic cyst stem cells throughout the lifetime of adult flies. However, a role for Notch signaling in adult males has only started to emerge recently. Nonetheless, we still don’t understand how the Notch pathway functions to regulate spermatogenesis. Notch has been established to be important for the fertility of multiple systems, including mammals, and must be properly regulated for proper spermatogenesis, but the …

Study Of Plants Used Against Infections By California Native American Tribes, Maria J. Rojas

Master's Theses

The objectives of this research were to evaluate the antibacterial activity and to determine the chemical composition of a list of medicinal plants used by Native Americans in California. Artemisia californica, Mimulus aurantiacus, Equisetum telmateia, Equisetum hyemale, and Marah fabacea were selected from a list of plants reported as having been used for ailments related to infections by tribes located in California. The extracts obtained through steam distillation from E. telmateia, E. hyemale and M. fabacea were assayed for in vitro antibacterial activity against 16 Gram-negative and 6 Gram-positive bacteria using disk diffusion assays and measuring the diameters of inhibition …

Assessment Of Genetic Diversity In Largetooth Sawfish, Pristis Pristis, Populations Over The 20th Century, Ann Fearing

Master's Theses

The Critically Endangered Largetooth Sawfish, Pristis pristis, experienced global declines in range and abundance over the past century and Australia is now their last stronghold. This research aimed to understand whether these declines have been accompanied by a reduction in levels of genetic diversity. Using P. pristis tissue samples sourced from natural history specimens, three fragments (616-bp, 386-bp, 141-bp) in the mitochondrial DNA (mtDNA) control region were PCR-amplified. At each fragment, significant genetic structure was found in P. pristis overall (Φ_ST=0.946, N=9; 0.813, N=54; 0.771, N=99). The Indo-West Pacific and Atlantic/Eastern Pacific each harbor genetically distinct lineages of …

Sensory Stressors Impact Species Responses Across Local And Continental Scales, Ashley A. Wilson

Master's Theses

Pervasive growth in industrialization and advances in technology now exposes much of the world to anthropogenic night light and noise (ANLN), which pose a global environmental challenge in terrestrial environments. An estimated one-tenth of the planet’s land area experiences artificial light at night — and that rises to 23% if skyglow is included. Moreover, anthropogenic noise is associated with urban development and transportation networks, as the ecological impact of roads alone is estimated to affect one-fifth of the total land cover of the United States and is increasing in space and intensity. Existing research involving impacts of light or noise …

Transgenerational Plasticity Causes Differences In Uv-Tolerance Of Intertidal And Subtidal Populations Of The Purple Sea Urchin, Strongylocentrotus Purpuratus, Yareli Alvarez, Nikki L. Adams

Master's Theses

Planktonic larvae of marine organisms are increasingly being exposed and required to respond to a changing physical environment. Adult sea urchins occupy both intertidal and subtidal waters and broadcast spawn gametes into the water column to contend with variable physical conditions. To answer how populations of invertebrates residing at different depths adequately prepare their offspring to cope with different levels of ultraviolet radiation (UVR), we collected adult purple sea urchins, Strongylocentrotus purpuratus, from four sites (two intertidal and two subtidal (~15 m deep)) on the central coast of CA to compare UV tolerance in offspring. Our measurements of UVA …

Assessing Seasonal Changes In Body Condition For Spotted (Phoca Largha), Ringed (Pusa Hispida), And Bearded (Erignathus Barbatus) Seals, Michelle Hartwick

Master's Theses

Anthropogenic global warming is causing unprecedented changes to occur within Arctic ecosystems. As sea ice continues to decline in both thickness and extent, ice-adapted species will be particularly affected. Specifically, Arctic seals are reliant on sea ice during critical life-history stages and many of their preferred prey depend on reliable patterns in annual sea ice cover. Thus, ongoing changes will likely affect the ability of Arctic seals to carry out key life-history tasks and maintain positive energy balance. One way to assess energy reserves is through examination of body condition. For seals, this is often done by measuring overall blubber …

Feeling Out Your Food: A Histological Analysis Of The Whisker System In Seals, Cameron Cooper

Master's Theses

The vibrissal (whisker) system is present in nearly all mammals and is especially important in deep-diving mammals. Pinnipeds (seals, sea lions, and walruses) have highly sensitive whiskers that are used to follow hydrodynamic trails created by their swimming prey. Each pinniped vibrissa is surrounded by a tripartite blood sinus system composed of an upper cavernous sinus (UCS), a ring sinus (RS), and a lower cavernous sinus (LCS). The UCS has been hypothesized to play a thermoregulatory role, insulating temperature sensitive mechanoreceptors located within the vibrissal follicle. The aim of this study was to examine this hypothesis by measuring and comparing …

Pismo Clams (Tivela Stultorum) In Califorina: Population Status, Habitat Associations, Reproduction, And Growth, Alexandria R. Marquardt

Master's Theses

Marine shellfish play a vital role in intertidal ecosystems and coastal communities, but many of these fisheries are small-scale and lack the necessary monitoring to ensure long-term sustainability. Effective management often requires information on key demographic parameters, such as population status, reproduction and growth. Pismo clams (Tivela stultorum) are a culturally important and iconic species in California, which supported a thriving commercial and recreational fishery throughout much of the 1900’s. However, Pismo clam populations have declined statewide in recent decades and are attributed to human harvest and predation by California sea otters (Enhydra lutris); However, no …

Historical And Contemporary Variables Affecting The Range And Distribution Of Aedes Aegypti, The Yellow Fever Mosquito, In The United States, Nicole Mackey

Master's Theses

Aedes aegypti, the primary mosquito vector of the yellow fever virus, threatens global health by passing on this virus, as well as chikungunya, dengue, and Zika viruses. Through its natural tendency to live in highly urban areas and bite human hosts; understanding the factors that affect the historical and current range of the pest is invaluable (Gubler, 1998). Although these viruses are not normally found in the United States, lack of vaccinations and wide-spread presence of the mosquito could lead to these diseases being reintroduced with potentially devastating effects (Monath, 2001). To determine a partial historical range of A. aegypti …

Thermal Ecology Of The Federally Endangered Blunt-Nosed Leopard Lizard, Kathleen N. Ivey

Master's Theses

Recognizing how climate change will impact populations can aid in making decisions about approaches for conservation of endangered species. The Blunt-nosed Leopard Lizard (Gambelia sila) is a federally endangered species that, despite protection, remains in extremely arid, hot areas and may be at risk of extirpation due to climate change. We collected data on the field-active body temperatures, preferred body temperatures, and upper thermal tolerance of G. sila. We then described available thermal habitat using biophysical models, which allowed us to (1) describe patterns in lizard body temperatures, microhabitat temperatures, and lizard microhabitat use, (2) quantify the …

Using Crispr-Cas9 As A Restriction Enzyme, Zack Crawley

Master's Theses

Restriction digests are a commonly utilized process for cleaving DNA at specific, but relatively common sites. Restriction enzymes have widespread use in DNA manipulation. CRISPR/Cas9 is a recently identified endonuclease which utilizes a customizable guide sequence to recognize and cut specific ~20 bp sites located in a DNA sequence. This preliminary research aimed to exploit the potential benefit of DNA restriction using the CRISPR/Cas9 procedure through alterations of different components involved in that system. We sought to refine existing CRISPR/Cas9 protocols and make a budget friendly, user-selectable CRISPR/Cas9 restriction digest protocol. The motivation for this research was to simplify and …

Investigating The Nightime Departures Of Glaucous-Winged Gulls (Larus Glaucescens) And The Role Of Social Facilitation, Devon Leigh Mcclain

Master's Theses

Daytime behaviors and occupancy patterns of Glaucous-winged Gulls (Larus glaucescens) have been described and can be mathematically predicted based on environmental factors. However, little is known about the nighttime behaviors of Glaucous-winged Gulls. I used trail cameras to study the daytime and nighttime colony occupancy patterns of Glaucous-winged Gulls on a breeding colony on Protection Island, Washington, USA. Early in the breeding season gulls desert the colony en masse during nighttime even after some gulls have initiated clutches. Using acoustic recording units to identify an acoustic cue that signals the onset of the coordinated nightly departures from the colony, I …

Exploring The Biological Function Of Carboxypeptidase O: Analysis Of Expression And Association With Chylomicrons And Lipid Droplets, Erika Bauza Nowotny

Master's Theses

Carboxypeptidase O (CPO) is a membrane-bound peptidase that cleaves acidic and polar C-terminal amino acids of peptides; however, its biological function remains unknown. CPO is strongly expressed in the small intestine, where it has been proposed to participate in digestion events at the brush border by extracellular cleavage of dietary peptides. At the subcellular level, CPO is anchored to the inner leaflet of the endoplasmic reticulum (ER) membrane, where it has been shown to associate with lipid droplets (LDs). The ER membrane also represents the site of iv chylomicron formation, a process that shares many similarities with that of LDs …

A Study Of Inactive Enzyme-Homologues: The Biochemical And Biological Function Of Ecm14 In Saccharomyces Cerevisiae, Robert Christian Mcdonald

Master's Theses

Like most major enzyme families, the M14 family of metallocarboxypeptidases (MCPs) contains several pseudoenzymes predicted to lack enzyme activity and with unknown molecular function. The genome of the yeast Saccharomyces cerevisiae encodes only one member of the M14 MCP family, a pseudoenzyme named Ecm14 proposed to function in the extracellular matrix. Ecm14 is found throughout ascomycete fungi, with a group of related pseudoenzymes found in basidiomycetes. Although the prodomain of Ecm14 can be cleaved in vivo and in vitro by endopeptidases, suggesting an activation mechanism, no activity has been detected using standard carboxypeptidase substrates.

In order to examine the function …