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Molecular And Enzymatic Resistance Of Culex Tarsalis To Pyrethroid And Organophosphate Insecticides, William Mortola

University of the Pacific Theses and Dissertations

Culex tarsalis, a vector for diseases like West Nile virus, is evolving resistance to pyrethroid and organophosphate insecticides used for agriculture and vector control in Northern California. Common mechanisms of resistance in other Culex species include the target-site mutations kdr and ace-1 and increased levels of detoxification enzymes (esterases, GSTs, and oxidases). This study contained two parts: Pyrethroid Individual study and an Organophosphate Preliminary study. For the Pyrethroid Individual study, the goal was to compare the prevalence of kdr mutations and detoxification enzymes between pyrethroid susceptible and resistant Cx. tarsalis individuals in Northern California. For the Organophosphate Preliminary study, the …

Beyond Cortisol: Indicators Of Stress And Negative Feedback In Plasma And Blubber Of Marine Mammals, Jessica Avalos

University of the Pacific Theses and Dissertations

Marine mammals play an important role in ecosystem stability. However, anthropogenic activity is compounding pressure on many already vulnerable populations. A potential consequence of anthropogenic disturbance is physiological stress, which can impact metabolism, immunity, and reproduction, especially if it occurs repeatedly. Previous studies on marine mammals have focused on acute stress, but the impacts of repeated stress are poorly understood. Due to its accessibility on land during haul-outs, the northern elephant seal (Mirounga angustirostris) is a good system in which to study the effects of stress in marine mammals. Stress stimulates the release of glucocorticoid hormones, primarily cortisol. Elevated cortisol …

Inhibition Of Staphylococcus Aureus Biofilm By Variovorax Paradoxus, Esther Gomez

University of the Pacific Theses and Dissertations

Staphylococcus aureus is one of the leading causes of fatal nosocomial infections. Often, S. aureus can grow as a biofilm which protects the population from the surrounding environment. Strains of S. aureus are resistant to virtually all known antibiotics on the market. Variovorax paradoxus is a soil microbe with many unusual metabolic activities. It has been previously observed that, V. paradoxus can inhibit the growth of S. aureus when in co-culture. In this work we report on inhibition of S. aureus biofilm formation by V. paradoxus due to a suspected inhibitory soluble factor.

Land-Use And Ant Biodiversity In California’S Central Valley, Laura L. Navarro

University of the Pacific Theses and Dissertations

The growing human population results in growing demand for land allocated to urban development and agricultural production (Godfray et al. 2010; Tilman et al. 2011; McDonnell and Hahs 2013; Alexander et al. 2015; Erlwein and Pauleit 2021). Changes to land allocation associated with agricultural and urban development will increasingly alter terrestrial ecosystems impacting biodiversity (Ricketts et al. 2001; McDonald et al. 2008). Ants are an ideal organism for monitoring changes in biodiversity related to land-use change due to their ubiquitous nature, high diversity, and their role as bioindicators. The goal of this study was to assess the diversity of the …

The Bgs 13 Mutant Of Pichia Pastoris And Its Effect On Structural Changes Of The Reporter Protein B-Lactogolbulin, Bushra Irshad

University of the Pacific Theses and Dissertations

Pichia pastoris, a methylotrophic yeast, is an ideal host for recombinant protein expression. It has the capability of performing many eukaryotic post-translational modifications and grows to high cell densities. However, P. pastoris’s secretion properties are not always efficient, and its secretory pathway mechanisms have not been thoroughly elucidated. A previously identified mutant strain, bgs13, was found to efficiently secrete most recombinant proteins tested, raising the possibility that this bgs13 mutant is a universal super secreter and understanding its secretion process is needed. In this study, we used a reporter protein, ?-lactoglobulin (b-LG), to perform structural analysis and comparisons of protein …

How Do They Do It? Using Omics Approaches To Explore Metabolic Responses Associated With Hypoxia And Exercise Tolerance In The Deepest Diving Pinniped, Elizabeth R. Piotrowski

University of the Pacific Theses and Dissertations

Marine mammals such as northern elephant seals (NES) routinely experience hypoxemia and ischemia-reperfusion events to many tissues during deep dives with no apparent adverse effects. Adaptations to diving include increased antioxidants and elevated oxygen storage capacity associated with high hemoprotein content in blood and muscle. Despite experiencing decreased oxygen tensions during diving, NES likely rely on the mobilization of large lipids stores and catabolism of fatty acids to provide energy to exercising muscle while diving. To identify potential regulatory mechanisms that may underly hypoxia and exercise tolerance in diving mammals, this study used system-wide approaches to characterize changes in genes …

Impacts Of Plastic Pollution On A Pelagic Marine Mammal, The Northern Elephant Seal, Lauren M. Kashiwabara

University of the Pacific Theses and Dissertations

As plastic pollution increases, top marine predators such as marine mammals are becoming increasingly susceptible to plastic particles and their additives. Plastic particles have been found in gastrointestinal tracts and scat of many marine mammals, and quantifying plastic pollution in those that are pelagic can provide insight into plastic pollution in mesopelagic ecosystems that are just beginning to be analyzed. Adapting well-developed laboratory techniques for microplastic (MP) isolation (i.e. density separation and chemical digestion), I isolated MPs from the scat of the deepest diving pinniped, the northern elephant seal (NES), and found that100% of scat samples (n=11) contained high counts …

Cpf1-Based Crispr Genome Editing In The Cyanobacterium N. Punctiforme, Soohan Woo

University of the Pacific Theses and Dissertations

CRISPR systems have been growing in their utility and their application throughout the biological field as researchers continue to grow in their understanding of the relatively novel genome editing technology. However, despite the potential of CRISPR as a genome editing tool, the complexity of applying this technology to a specific organism calls for custom modifications to the system to improve its success rate. In this project, a CRISPR-Cpf1 system that can be effectively employed in the cyanobacterium Nostoc punctiforme was designed, with a focus on the hormogonium development of this species. Multiple plasmids containing the CRISPR system and targeting different …

Changes In The Vertical Stratification Of Neotropical Nymphalidae At Forest Edges In Relation To Light And Temperature Conditions, Brian Koji Oye

University of the Pacific Theses and Dissertations

The composition of neotropical fruit-feeding nymphalid butterflies assemblages often varies by location and stratum within a forest. Recent work has shown that vertical stratification in particular may serve as barrier to gene flow, indicating the potential role vertical stratification may play in evolution. At forest edges, the distinction between assemblages has been described to decrease, with species considered to be canopy specialists descending to the forest understory. The similarity in light conditions between the canopy and understory strata at edges or disturbed habitat is hypothesized to be responsible for this phenomenon. We conducted a study using standardized sampling to document …

Prevalence Of Dirofilaria Immitis In Southern California’S Invasive Aedes Species And Native Culiseta Incidens, Zaina Chaban

University of the Pacific Theses and Dissertations

Dirofilaria immitis is a mosquito-borne parasite that causes dog heartworm disease, effecting over 100,000 dogs in the United States each year (CAPC - Parasite Prevalence Maps., 2021). Increased disease reports are commonly attributed to an increase in the local mosquito vector population. Since 2013, dog heartworm disease cases have increased by approximately 21% in the United States as reported by the American Heartworm Society. During the same time, invasive mosquitoes belonging to the genus Aedes have been found in Southern California and spread to other areas. The purpose of our research was to determine the prevalence of Dirofilaria …

Amphibian Vocalization: Implications Of A Novel Laryngeal Muscle In The Calling Mechanisms Of The TúNgara Frog Engystomops Pustulosus, Amy D. Lagorio

University of the Pacific Theses and Dissertations

The current functional model of the anuran larynx includes four pairs of laryngeal muscles. Their contractions do not account, however, for the behavioral control of call complexity observed in male túngara frogs (Engystomops pustulosus), which optionally add a secondary note with distinct harmonic structure to their advertisement call. Examination of the túngara frog's laryngeal morphology through dissection, microtomography, and resin histology has revealed that the m. dilatator laryngis is divided into two separate bundles (superficial and deep). The superficial bundle closely matches the typical description of the m. dilatator laryngis and is well positioned to open the glottis. …

Proteomic Analysis Of Fetal Rat Neural Stem Cells After Treatment With Hericium Erinaceus, Bright Adam Test

University of the Pacific Theses and Dissertations

The fungus, Hericium erinaceus, has outstanding chemical properties, displaying health benefits in digestive, hepatic, and nervous tissues. Its ease of accessibility and use makes it one of the most common substances used for treatment in Eastern medicine. More and more recent research is confirming the incredible health benefits of this fungus, especially the impact that is seen on nervous tissue growth and recovery post-treatment. Such neurite outgrowth and myelin sheath regeneration could illustrate the beginning of the cure to lifelong neurodegenerative diseases such as Multiple Sclerosis. In this first-of-its-kind study, we cultured and differentiated fetal rat neural stem cells while …

Transcriptome Analysis For Novel Peptide In Breeding Gland Of Hymenochirus Boettgeri, Minjin Ko

University of the Pacific Theses and Dissertations

The primary goal of the project was to find nucleotide sequences potentially encoding a pheromone from the breeding gland of Hymenochirus boettgeri. The reasons in searching for the sequence of a pheromone were to better understand the organism and to use the information for application in reproduction of other species. Due to climate change and rampant deforestation, such as in Africa’s Congo Basin, many amphibian species are being threatened. With these increasing threats, a viable option for the future may be breeding in captivity for the amphibian species. Pheromone characterization from the breeding gland of Hymenochirus boettgeri may help with …

City Limits: Heat Tolerance Is Influenced By Body Size And Hydration State In An Urban Ant Community, Dustin Jerald Johnson

University of the Pacific Theses and Dissertations

Cities are rapidly expanding, and global warming is intensified in urban environments due to the urban heat island effect. Therefore, urban animals may be particularly susceptible to warming associated with ongoing climate change. Thus, I used a comparative and manipulative approach to test three related hypotheses about the determinants of heat tolerance or critical thermal maximum (CTmax) in urban ants—specifically, that (1) body size, (2) hydration status, and (3) preferred micro-environments influence CTmax. I further tested a fourth hypothesis that native species are particularly physiologically vulnerable in urban environments. I manipulated water access and determined CTmax for 11 species common …

A Trio Of Sigma Factors Control Hormogonium Development In Nostoc Punctiforme, Alfonso Gonzalez Jr.

University of the Pacific Theses and Dissertations

Cyanobacteria are prokaryotes capable of oxygenic photosynthesis, and for many species, nitrogen fixation, giving cyanobacteria an important role in global carbon and nitrogen cycles. Furthermore, multicellular filamentous cyanobacteria are developmentally complex, capable of differentiation into different cell types, including cells capable of nitrogen fixation and cells for motility, making them an ideal platform for studying development, as well as for practical use in biotechnology. Understanding how developmental programmes are activated require an understanding of the role of alternative sigma factors, which are required for transcriptional activation in bacteria. In order to investigate the gene regulatory network and to determine the …

Characterization And Analysis Of Proteins Secreted By The Mutant Pichia Pastoris Strain, Bgs13, Christopher Alan Naranjo

University of the Pacific Theses and Dissertations

The methylotrophic yeast Pichia pastoris has been utilized for heterologous protein expression for research, clinical, and industrial purposes to produce thousands of recombinant protein products. Because P. pastoris secretes very few of its own proteins, the exported recombinant protein is the major polypeptide in the extracellular medium, making purification relatively easy. Unfortunately, a disadvantage to the programmed export is that some recombinant proteins intended for secretion are retained within the cell and may be subsequently degraded. A mutant strain isolated in our lab, containing a pREMI-derived disruption of the BGS13 gene, has displayed elevated levels of secretion for a variety …

Phylogenomic Analyses Clarify Butterfly Species Within The Genus Speyeria Despite Evidence Of A Recent Adaptive Radiation, Erin Thompson

University of the Pacific Theses and Dissertations

The North American genus Speyeria is an especially challenging radiation of butterflies due to ongoing hybridization, incomplete lineage sorting, and similar morphological characters among species. Adaptive radiations often require considerable evidence in order to resolve the evolutionary relationships of closely related individuals. Previous studies of this genus have found paraphyly among species and have been unable to disentangle these taxa due to a lack of data and/or incomplete sampling of the genus. As a result, the interspecific relationships among Speyeria remain unresolved. In an attempt to achieve phylogenetic resolution of the genus, we conducted population genomic and phylogenomic analyses of …

Structural Characterization Of Black Widow Spider Dragline Silk Proteins Crp1 And Crp4, Mikayla Shanafelt

University of the Pacific Theses and Dissertations

Spider dragline silk is a biomaterial with outstanding material properties, possessing high-tensile strength and toughness. In nature, dragline silk serves a central role during spider locomotion and web construction. Today, scientists are racing to elucidate the molecular machinery governing silk extrusion, attempting to translate this knowledge into a mimicry process in the laboratory to create synthetic fibers for a wide range of different applications. During extrusion, it has been established that biochemical and mechanical forces govern spidroin folding, aggregation, and assembly. In black widow spiders, at least 7 different proteins have been identified as constituents of dragline silk fibers. These …

Development Of A Biomarker Panel For Identifying Stressed Marine Mammals, Laura Pujade

University of the Pacific Theses and Dissertations

Increasing anthropogenic disturbance in marine ecosystems such as fishing, oil-drilling, and noise pollution can have detrimental effects on the reproduction and survival of apex predators such as marine mammals. Stress activates the hypothalamic-pituitary-adrenal (HPA) axis, resulting in increased circulating glucocorticoid (GCs) hormones, which alter expression of target genes encoding metabolic enzymes and other mediators of stress. Prolonged HPA axis stimulation may increase catabolism of nutrient stores and suppress immune and reproductive functions, impacting the fitness of marine mammals. GCs measurements are used to identify wild animals experiencing stress. However, these measurements may not be sensitive enough to distinguish between an …

Spatial And Temporal Dynamics Of Batesian Mimicry Between Adelpha Californica And Limenitis Lorquini, Louis Albert Prusa

University of the Pacific Theses and Dissertations

Conspicuous coloration is one of the main ways that animals communicate. The use of eye-catching color patterns to warn predators of an unprofitable trait is referred to as aposematism. Once predators learn to recognize the color pattern, a new signaling niche becomes available where other species can share the same signal. This mimicry niche can involve a “hide in plain sight” strategy by mimicking or parasitizing this signal, with mimics lacking the defense and associated costs that make them unprofitable. This is termed Batesian mimicry, and it decreases predation by taking advantage of the memory and learning of the predator …

Unknown And Cryptic Diversity In The Adelpha Serpa-Group, Cassidi Rush

University of the Pacific Theses and Dissertations

The tropics are host to incredible insect diversity. One of the most charismatic groups that exhibit this diversity are the butterflies. Despite the tropical butterfly fauna being heavily researched, there remains much hidden diversity in the form of undescribed life histories and cryptic species. This is especially true among the species rich Nymphalidae, the brush-footed butterflies. Species in the genus Adelpha are known to be “the most trying taxonomically of all nymphalids” DeVries (1987), and as such are fruitful ground for uncovering unknown diversity. About half of the species within Adelpha have undescribed life histories, while A. serpa stands out …

Should I Stay Or Should I Go? Complex Environments Drive The Developmental Plasticity Of Flight Capacity And Flight-Related Tradeoffs, Jordan R. Glass

University of the Pacific Theses and Dissertations

Animals must balance multiple, fitness-related traits in environments that are complex and characterized by co-varying factors, such as co-variation in temperature and food availability. Thus, experiments manipulating multiple environmental factors provide valuable insight into the role of the environment in shaping not only important traits (e.g., dispersal capacity or reproduction), but also trait-trait interactions (e.g., trade-offs between traits). We employed a multi-factorial design to manipulate variation in temperature (constant 28°C vs. 28±5°C daily cycle) and food availability (unlimited vs. intermittent access) throughout development in the sand field cricket, Gryllus firmus. We found that fitness-related, life-history traits and trait trade-offs can …

Endocrine Responses To Repeated Adrenocorticotropic Hormone Administration In Free-Ranging Elephant, Molly Mccormley

University of the Pacific Theses and Dissertations

Understanding the physiological response of marine mammals to anthropogenic stressors can inform marine ecosystem conservation strategies. Stress stimulates release of glucocorticoid (GC) hormones, which increase energy substrate availability while suppressing energy-intensive processes. Exposure to repeated stressors can potentially affect an animal’s ability to respond to and recover from subsequent challenges. To assess the endocrine response of a marine mammal to repeated stressors, we administered adrenocorticotropic hormone (ACTH) to free-ranging juvenile northern elephant seals (Mirounga angustirostris; n=7) once daily for four days. ACTH administration induced significant, but transient (<24 h) elevation in circulating cortisol levels (p < 0.0001). These increases did not vary in magnitude between the first ACTH challenge on day 1 and the last challenge on day 4. In contrast, aldosterone levels remained elevated above baseline for at least 24 hours after each ACTH injection (p < 0.001), and responses were greater on day 4 than day 1 (p < 0.01). Total triiodothyronine (tT3) levels were decreased on day 4 relative to day 1 (p < 0.01), while reverse triiodothyronine (rT3) concentrations increased relative to baseline on days 1 and 4 (p < 0.001) in response to ACTH, indicating a suppression of thyroid hormone secretion. There was no effect of ACTH on the sex steroid dehydroepiandrosterone (DHEA). These results suggest that elephant seals are able to mount adrenal responses to multiple ACTH challenges. However, repeated stress results in facilitation of aldosterone secretion and suppression of tT3, which may impact osmoregulation and metabolism. We propose that aldosterone and tT3 are informative additional indicators of repeated stress in marine mammals.

Evidence That A Partner-Switching Regulatory System Modulates Hormogonium Motility In The Filamentous Cyanobacterium Nostoc Punctiforme, Kelsey Wynne Riley

University of the Pacific Theses and Dissertations

Partner-switching regulatory systems (PSRSs) are utilized by many different bacteria to regulate a wide array of cellular responses, from stress response to expression of virulence factors. The filamentous cyanobacterium Nostoc punctiforme can transiently differentiate motile filaments, called hormogonia, in response to various changes in the environment. Hormogonia utilize a Type IV pilus (T4P) complex in conjunction with a secreted polysaccharide for gliding motility along solid surfaces. This study identified three genes, designated hmpU, hmpW, and hmpV, encoding the protein components of a PSRS involved in regulation of hormogonium motility in N. punctiforme. Although mutant strains with in-frame deletions in hmpU, …

Neuromuscular Control Of The Calling Apparatus In The Túngara Frog (Engystomops Pustulosus), Kiran Kaur Grewal

University of the Pacific Theses and Dissertations

Male túngara frogs can add a distinctive note ("chuck”) to their mating call. Production of the chuck involves vibrating a pair of laryngeal fibrous masses that is attached to the vocal cords. The muscular control of this mechanism remains unknown. Recent studies revealed a split in the laryngeal dilator muscle, which unveiled the deep dilator as a novel laryngeal muscle with unique attachments, innervation, and (likely) function. The deep dilator may position the fibrous masses for chuck production. The goals of this study were 1) to confirm the innervation of the novel muscle through electrophysiology; and 2) to determine the …

Auranofin Targets Thioredoxin Reductases In Trichomonas Vaginalis, Jose Jauregui

University of the Pacific Theses and Dissertations

Trichomonas vaginalis is an anaerobic, parasitic protozoan, responsible for trichomoniasis, the world’s most common, non-viral sexually transmitted infection. Lacking many of the defenses present in other organisms to combat oxidative stress, Trichomonas vaginalis relies extensively on the thioredoxin system—NADPH, thioredoxin reductase, and thioredoxin—as a means to protect against exposure to excess oxygen. Current trichomoniasis treatment relies exclusively on the 5-nitroimidazole drugs, but fear of drug-resistant strains and allergic reactions to 5-nitroimidazole treatment necessitate the discovery of a new treatment method for trichomoniasis. Previous research has shown that auranofin, an FDA-approved drug, was effective at inhibiting activity of one of Trichomonas …

Studies On Development In Euphilomedes Ostracods: Embryology, Nervous System Development, And The Genetics Of Sexually Dimorphic Eye Development, Kristina Koyama

University of the Pacific Theses and Dissertations

Model organism studies have been fundamental in understanding evolutionary and developmental biology. However, non-model organisms present opportunities to study unique characteristics and as comparisons to model organisms, leading us toward broader and more relevant perspectives on diversity. The Euphilomedes genus of ostracods is an example of a non-model group with potential for evolutionary and developmental studies.

Ostracoda is an ancient, basally branching lineage of Crustaceans with a complete and prodigious fossil record. Despite the group’s promise for evolutionary studies, much remains unknown about the basic biology of this clade. There are a limited number of embryogenesis studies in Ostracoda; here, …

Vector Competence Of Aedes Sierrensis And Culex Pipiens Complex (Diptera: Culicidae) For Dirofilaria Immitis (Spirurida: Onchocercidae) In Northern California, Jeffrey Allan Kurosaka

University of the Pacific Theses and Dissertations

Dirofilaria immitis Leidy (dog heartworm) is a life-threatening parasite transmitted by mosquitoes to domestic dogs. Endemic in the eastern United States, cases have become more prevalent over the last few decades. While prevalence in California is generally low, Lake and San Joaquin Counties have reported rates comparable to the East Coast at 3.73% and 0.71%(CAPC 2017), respectively. Aedes sierrensis is thought to be responsible for transmission in California, but in some cases, it exists in inadequate quantities and temporal ranges to explain parasite activity. Based on Huang et al. (2013) and Tran (2016), bloodfeeding patterns, and other vector criteria, Culex …

The Effects Of Adrenergic And Cholinergic Stimulation On Skin Gland Secretions In The Dwarf African Frog Hymenochirus Curtipes, Daniel H. Gong

University of the Pacific Theses and Dissertations

Many studies have been done on the neural control of serous gland secretion in the skin of frogs and newts. However, no studies have been published on the effects of adrenergic and cholinergic neurotransmitters on the sexually dimorphic breeding glands of male frogs. The present study examined the effects of neurotransmitters on the serous and breeding glands of Hymenochirus curtipes. Explants of dorsal skin and postaxial skin (containing whole breeding glands) were incubated in vitro with epinephrine, norepinephrine or acetylcholine for 30 minutes. The explants were then preserved and examined histologically for signs of secretion. The area and perimeter of …

Studies On The Trematode Larva Neascus, Thomas Reyes

University of the Pacific Theses and Dissertations

During the spring semesters of 1955 and 1956, while the writer was under the supervision of Dr. A. E. Noble, a preliminary survey was initiated on parasites in local fishes, amphibians, and reptiles occurring in the vicinity of Stockton, California. The collection of specimens in this survey included sixteen green sunfish, Lepomis cyanella, and two bluegills, L. macrochirus. Larval trematodes recovered from the heart and liver of these specimens belonged to the family Diplostomatidae Poirier (1886) which is characterized by a conspicuous constriction separating the fore and hind-bodies. The leaf-like forebody with the lateral borders converging ventrally to form a …