Biology Commons^™

A Study On The Function Of 14-3-3sigma In Regulating Cancer Energy Metabolism, Liem M. Phan, Liem M. Phan

Dissertations & Theses (Open Access)

Metabolic reprogramming has been shown to be a major cancer hallmark providing tumor cells with significant advantages for survival, proliferation, growth, metastasis and resistance against anti-cancer therapies. Glycolysis, glutaminolysis and mitochondrial biogenesis are among the most essential cancer metabolic alterations because these pathways provide cancer cells with not only energy but also crucial metabolites to support large-scale biosynthesis, rapid proliferation and tumorigenesis. In this study, we find that 14-3-3σ suppresses all these three metabolic processes by promoting the degradation of their main driver, c-Myc. In fact, 14-3-3s significantly enhances c-Myc poly-ubiquitination and subsequent degradation, reduces c-Myc transcriptional activity, and down-regulates …

A Time Series Analysis Method Using Hidden Variables For Gene Network Reconstruction, Xi Wu

Dissertations

The DNA microarray technology can be applied to obtain time series data which contains thousands of genes and tens of time points. When confront the great amount of data points a fast and effective method must be constructed to extract useful information. The assumption that the interactions between genes are static in the time series data is made. After made the assumption how to reconstruct those interactions becomes a difficulty problem. Since the underlying interactions between genes are complicated, which involve transcription, translation and protein-protein interaction, to construct a model from physicochemistry is almost impossible/effortless. The popular methods constructed from …

The Role Of The Cysteine/Glutathione Regulatory Genes Cdo1, Gsh1, And Gsh2 In Yeast-Mold Dimorphism Of The Pathogenic Fungus Histoplasma Capsulatum, Melissa Anne Adams

Dissertations

The dimorphism of Histoplasma capsulatum (Hc) from a mold to yeast is regulated by many environmental factors such as temperature and thiol concentrations. Histoplasma exists in the soil (or in vitro at 25ºC) as a multicellular saprophytic mold. In the lungs of an infected host (or in vitro at 37ºC), a shift to the unicellular parasitic yeast occurs. Sulfhydryl groups (-SH), especially cysteine, are necessary in the culture medium for the mold to yeast transition. Cysteine is the precursor for the synthesis of glutathione. Enzymes involved in the cysteine metabolism pathway are being studied in order to evaluate …

Characterization Of Fhua 104/149c: A Double Cysteine Fhua Mutant With Normal Binding And Diminished Transport, Ada K. Hagan

Electronic Theses and Dissertations

Iron is an essential element for most bacteria and is commonly acquired by siderophores, molecules secreted under iron restricted environment to bind ferric iron. Gram negative cells actively uptake these complexes via outer membrane-transport proteins such as FhuA in Escherichia coli. Structural analysis of receptors revealed a conserved β-barrel occluded by an N-terminal plug domain. The cell membrane TonB/ExbB/ExbD complex presumably supplies energy via interaction between the FhuA N-terminal TonB box and the C-terminal domain of TonB. In order to better understand the mechanism of action the FhuA mutant 104/149C, tethering the central β-strands 4 and 6 of the …

The Effects Of Temperature On Energy Utilization By Marine Invertebrate Larvae, Elizabeth Whitehill

All Dissertations

Most ectothermic organisms are larger when reared at lower temperatures and temperature can greatly affect an organism's physiological state, so understanding how temperature affects larval size and quality can provide insight into how the larval thermal environment affects post-metamorphic success. Because quality is often defined in terms of size and energy content, I focused on how temperature affects energy utilization by larvae and how differences in energy accumulation and utilization may carry over into the juvenile stage. Marine invertebrate larvae are often classified into two groups: larvae from smaller eggs that must obtain food from the environment in order to …

Restoration Of Biological Soil Crust On Disturbed Gypsiferous Soils In Lake Mead National Recreation Area, Eastern Mojave Desert, Lindsay P. Chiquoine

UNLV Theses, Dissertations, Professional Papers, and Capstones

Biological soil crusts (BSCs) are sensitive to anthropogenic disturbances. Natural recovery takes many years. Active restoration decreases recovery time. Native BSC inocula, which included lichens and mosses, salvaged from gypsiferous soil habitats in Lake Mead National Recreation Area (LMNRA) in the eastern Mojave Desert were stored dry for two years and applied to disturbed soil after a road reconstruction in LMNRA and also used in laboratory experiments to test inoculation technique effectiveness. After 18 months, field results revealed positive relationships between inoculation and the presence of macroscopic BSC cover, cyanobacteria abundance, soil stability, and ammonium concentrations. Chlorophyll fluorescence monitoring of …

Biogenic Amine Levels Correlate With Time Of Day, Age, Light Cycle, And Aggressive State In The Flesh Fly, Sarcophaga Crassipalpis, Veronica L. Fregoso

Electronic Theses and Dissertations

The biogenic amines serotonin (5HT), dopamine (DA), and octopamine (OA) have been indicated in the regulation of behaviors, including aggression. The flesh fly, Sarcophaga crassipalpis, was used to investigate ontogenetic and circadian changes in amines and aggression. Heads of male flies were analyzed for amine content using high performance liquid chromatography with electrochemical detection (HPLC-ECD) at 3 time points on each of 4 consecutive days in 2 light cycles, 12:12 LD and 15:9 LD. Both DA and OA levels decreased with age. Light-cycle dependent differences were observed for all amines in overall levels and patterns of change throughout the …

Conservation Genetics Of A Spotted Salamander (Ambystoma Maculatum (Shaw 1802)) Local Population In Southeast Tennessee, Daniel Scott Armstrong

Masters Theses and Doctoral Dissertations

Currently there is a worldwide amphibian decline with numerous causes. Because of this, it is important to understand how genetic variation in local amphibian populations is affected by disturbance. The goal of this study was to assess the genetic impacts of past chemical and ammunition storage and present industrialization on a local population of Ambystoma maculatum (Shaw 1802) using thirteen microsatellite markers. Most loci exhibited no loss of heterozygosity but the low effective population size may indicate vulnerability to future declines. No population substructure or sex-biased dispersal was detected. Possible explanations for the reduction in genetic diversity at four loci …

Demographics And Seasonal Abundance Of Sportfish In Three Thermal Habitats Of Coffeen Lake, Anthony Paul Porreca

Masters Theses

No abstract provided.

The Rise And Fall Of Kin Structure In The Neotropical, Family-Living Buff-Breasted Wren (Cantorchilus Leucotis) In Gamboa, Panama, Sarah C. Alessi

Masters Theses

Family-living species provide an exciting model to examine how natal dispersal and kin structure influence genetic structuring within local populations. Juvenile buff-breasted wrens (Cantorchilus leucotis) of both sexes delay dispersal and exhibit short-distance natal dispersal, which should lead to kin-structured populations in which relatives of both sexes occupy neighboring territories. Blood samples collected from juvenile and adult wrens in Gamboa, Panama were analyzed using microsatellite markers to determine whether related individuals are spatially clustered on neighboring territories, spatial clusters of relatives change over time, and if kin structure is sex-specific. Global and local spatial autocorrelation analyses detected genetic …

A Genetic, Transgenic, And Transcriptomic Analysis Of Larval Salivary Gland Physiology In Drosophila Melanogaster, Elana A. Paladino

UNLV Theses, Dissertations, Professional Papers, and Capstones

Cholesterol is the precursor to a unique class of lipophilic signaling molecules called steroid hormones that initiate the development of sexual characteristics, reactions to stress, and maintenance of metabolism, among many other functions. Although much progress has been made in understanding the function of these signaling hormones, we do not fully understand how a single steroid can cause many distinct, tissue-specific responses. Drosophila melanogaster is an effective model for understanding steroid hormone action because of its simplicity. The steroid molting hormone 20-hydroxyecdysone (hereafter, 20E) is the primary active steroid in Drosophila and mediates not only larval molts and the emergence …

Natural And Lignocellulose-Enriched Microbial Communities In Great Boiling Spring, Nv, Jessica Cole

UNLV Theses, Dissertations, Professional Papers, and Capstones

The natural microbial communities present in Great Boiling Spring were investigated and contrasted against those present after in situ enrichment with lignocellulose. High-throughput cultivation-independent DNA sequencing of the V8 region of the small subunit (SSU) rRNA gene generated a total of 274,119 quality-filtered pyrosequencing fragments. Twelve natural spring samples were analyzed, including four high-temperature water samples and eight sediment samples ranging from 87 - 62 °C. Eight lignocellulosic enrichments incubated in the spring sediment and water at two high-temperature sites were analyzed. The natural water communities were found to be extremely uneven but relatively constant throughout time. The natural sediment …

Cold Tolerance Of Each Life Stage Of The Sub-Alpine Willow Leaf Beetle, Chrysomela Aeneicollis, Evelyn C. Boychuk

Electronic Thesis and Dissertation Repository

To understand the potential effects of climate change on the sub-alpine willow leaf beetle, the cold tolerance strategy and mechanisms involved in cold tolerance were investigated for all life stages. Microhabitat choice and microclimate temperatures within each microhabitat were related to median lethal temperature for each life stage. Summer active and quiescent adults are freeze tolerant, eggs and pupae are freeze avoidant and all larval stages are chill susceptible. Quiescent adults accumulated the highest concentration of glycerol (~24 mM) and haemolymph osmolality (875 mOsm). Haemolymph from pupae had angular crystals suggestive of antifreeze agent activity, but this was absent in …

The Influence Of Habitat Composition And Configuration On The Genetic Structure Of The Pitcher Plant Midge, Katie Millette

Electronic Thesis and Dissertation Repository

A major question in landscape genetics is how habitat structure influences spatial patterns of genetic differentiation. In this study, I evaluate the relative importance and effects of aspects of habitat composition (habitat amount) and configuration (patch size and isolation) on the spatial genetic structure of the pitcher plant midge, Metriocnemus knabi, whose larvae are found exclusively within the water-filled leaves of pitcher plants (Sarracenia purpurea) in a system that is naturally patchy at multiple spatial scales (i.e., leaf, plant, cluster, bog). I estimated genetic differentiation (F_ST) among leaves, plants, and clusters using 11 microsatellite …

Na+/K+-Atpase Isoform Regulation In Three-Spine Stickleback (Gasterosteus Aculeatus) During Salinity Acclimation, Shelby Judd

College of Science and Health Theses and Dissertations

Most marine and all freshwater fishes regulate the ionic and osmotic composition of their extracellular fluids different from the outside environment. The gills play a prominent osmoregulatory role in maintaining whole body ion and water balance in fish living in both freshwater and saltwater environments. The ability of the gill to regulate salts is dependent on the action of the Na⁺/K⁺-ATPase. When euryhaline fishes, fishes able to tolerate changes in external salinity, experience changes in environmental salinity, they alter their gill physiology and Na⁺/K⁺-ATPase activity to handle changing osmotic and ionic stresses. …

Burrowing Owl (Athene Cunicularia) Nesting Ecology In Western Kansas, Carol D. Grover-Mariner

Master's Theses

The Burrowing Owl (Athene cunicularia) is a common occupant of Smoky Valley Ranch located in Logan County, Kansas, where the abundance of black-tailed prairie dog (Cynomys ludovicianus) burrows provides ideal habitat for the Burrowing Owl. The objectives of the study were to 1) estimate the densities of black-tailed prairie dog colonies through visual counts, 2) estimate nesting success and nest survival probabilities of the Burrowing Owl with the use of a burrow camera, and 3) estimate post-fledging dispersal and return rate of juvenile Burrowing Owl the following season. I located 96 potential nests from 24 March through 2 July 2007 …

Characterization Of The Stem Cell Niche In Drosophila Testes, Vittorio Mena Jr.

Seton Hall University Dissertations and Theses (ETDs)

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Spatial And Oceanographic Factors Affecting Black-Legged Kittiwake And Thick-Billed Murre Distributions In The Southeastern Bering Sea, Brian Hoover

Capstone Projects and Master's Theses

The distribution patterns of Thick-billed Murres (Uria lomvia) and Black-legged Kittiwakes (Rissa tridactyla) in the southeastern Bering Sea were documented at sea during vessel-based surveys in July-August of 2008 and 2009. The relationships of murre and kittiwake densities with environmental variables were investigated using binomial generalized additive models (GAMs) to model the presence or absence of birds, and Gamma-error distribution GAMs to model the positive densities of birds. Environmental variables included oceanographic factors (Chlorophyll, Chlorophyll anomalies, Daily SST, Monthly SST), spatial factors (Distance to nearest colony, Distance to 300m shelf break, Depth), and a temporal factor (Year). Nocturnal surveys were …

West Nile Virus Seroreversion And The Influence Of Herd Immunity On Disease Risk In A Long-Term Study Of Free-Ranging Birds, Eileen M. Mckee

All Student Theses

The transmission and amplification of West Nile virus (WNV) is driven by the number of susceptible avian hosts. The quantity of susceptible hosts is determined by 1) recruitment of juvenile birds during the breeding season, 2) adult birds previously unexposed to WNV, and 3) adult birds with waning antibody titers. Although rarely tested, avian herd immunity and seroreversion could have a direct impact on Culex infection rate, a proxy for the reproductive number of WNV. In this study, we utilized data from a seven year study investigating WNV transmission ecology in suburban Chicago, Illinois. We tested the hypothesis that herd …

Patterns Of Chemosensory Behavior In A Closed Population Of Wild African Elephants (Loxodonta Africana), Russell W. Blogg

Electronic Theses and Dissertations

Chemosensory behaviors are used by many mammalian species to assess chemical signals in the environment. These chemical signals may contain important information about reproductive state, identity, status, or location of conspecifics. Elephants are a long-lived species and males reproduce at a much later age than females, which provides a protracted developmental period for males. This study examined chemosensory behaviors in a population of African elephants living in Addo Elephant National Park, South Africa and demonstrated that patterns emerge as elephants develop and approach sexual maturity. Older pubescent males (15-19 year olds) performed more chemosensory behaviors than younger pubescent males (10-14 …

Predation Risk And Colony Structure In The Pea Aphid, Acyrthosiphon Pisum, Carl Nicolas Keiser

Electronic Theses and Dissertations

Many organisms live in transient or permanent aggregations to reduce individual predation risk. Hamilton's "Selfish Herd" theory states that an individual should assume a central position within a group to decrease individual predation risk relative to that of its neighbors (i.e., individuals should be selfish). This theory, however, cannot predict the spatial distribution of individuals within clonal aggregations, that is, when individuals are genetically identical (the "evolutionary self"). As aphids (small, herbivorous insects) are parthenogenetic, emit alarm signals, and have high levels of phenotypic plasticity to cope with environmental stressors like predation risk, they are a model organism for investigating …

The Effects Of Locomotor Posture On Kinematics, Performance And Behavior During Obstacle Negotiation In Lizards, Jessica Self

Electronic Theses and Dissertations

The ability to efficiently move over uneven terrain is critical for most terrestrial animals. Bipedal running is common in lizard species, however the biological advantage of a bipedal running posture remains uncertain. I examined the hypothesis that a bipedal posture is advantageous when crossing obstacles. Particularly, I determined whether kinematic adjustments differ among four focal species with contrasting body forms and ecology. I also examined how sprint speed changed when crossing obstacles with a quadrupedal versus a bipedal posture. I quantified kinematics from high-speed video (300 frames/second) of lizards running down a 3m runway both with and without the presence …

Spatial And Temporal Immune Response In House Flies In Response To Ingestion Of Bacillus Cereus And Eschericha Coli 0157-H7, Adam Fleming

Electronic Theses and Dissertations

House flies (Musca domestica L.) feed and breed on septic substrates, putting them in direct contact with a multitude of disease causing agents and can act as a bridge for those agents to humans. The house fly has previously been shown to carry many different species of bacteria that are pathogenic. Escherichia coli O157:H7 is a pathogenic enterohemorrhagic serotype of E. coli that can be vectored by the house fly. Bacillus cereus is a foodborne pathogen that has also been isolated from the house fly in previous studies. To examine vector potential for these pathogens, house flies were fed green …

Role Of Provisions And Season On Foraging And Female Dominance Behavior In Ring-Tailed Lemurs (Lemur Catta) On St. Catherine's Island, Timothy Moore

Electronic Theses and Dissertations

Madagascar is undergoing habitat destruction and degradation that is threatening its unique species, including ring-tailed lemurs. Ring-tailed lemurs (Lemur catta) live in matriarchal groups composed of a dominant female, adult males, subadult males and females, and young. Due to their dominance, it has been suggested that female ringtailed lemurs have access to the highest quality resources and can monopolize food patches. Lemurs on St. Catherine's are free ranging and have unlimited access to natural food sources, but they are also provisioned with supplementary food to ensure a balanced diet. My study aimed to determine the impact of provisions on female …

Bird Use Of Cumberland Island's Freshwater Wetlands, Lisa Dlugolecki

Electronic Theses and Dissertations

Cumberland Island is the southernmost barrier island off the coast of Georgia. Its freshwater wetlands are an important, rare habitat to have on a barrier island surrounded by saltmarsh and ocean. Many species of birds require freshwater wetlands as feeding, roosting and nesting grounds. However, the freshwater wetlands on Cumberland Island have been impacted by humans for centuries causing birds to abandon their historic nesting ground. Known land use histories of Cumberland Island's freshwater wetlands were gathered to try and determine how the wetlands changed over time Wetlands were analyzed for presence of wetland-dependent birds and recorded. Thirty-six species of …

Origin Of Great Lakes Brown Trout, Salmo Trutta: A Phylogeographic Analysis Using Mtdna Sequence Variation, David Baisch

Masters Theses

The brown trout, Salmo trutta, was first introduced to the Laurentian Great Lakes in 1887 from European broodstocks to found a recreational salmonid fishery; however, the origins of these progenitor lineages remain largely unknown. Trout from these regions are very specialized to their native habitats and matching North American stocks to similar watersheds may help increase survivability by introducing the stock to a more appropriate environment. The objective of this study was to determine the European origins of brown trout found in the Great Lakes. We analyzed 144 brown trout from ten watersheds across Michigan and Wisconsin and identified …

Involvement Of Hexokinase1 In Plant Growth Promotion As Mediated By Burkholderia Phytofimans, Jae Min Park

Electronic Thesis and Dissertation Repository

Burkholderia phytofirmans strain PsJN consistently enhanced the growth of potato plants in vitro. The role of hexokinase1 in glucose phosphorylation was investigated in plants with PsJN. Increased hexokinase1 activity only in roots of PsJN-treated plants cultivar Kennebec suggests that hexokinase1 is associated with plant root and stem growth.

Plant growth with PsJN was determined when plants were grown with different sugars at various concentrations. PsJN-treated plants expressed diverse forms of growth promotion. When growth promotion did occur, hexokinase1 activity also increased. Growth promotion and hexokinase1 activity appear to be correlated to the enzyme to recognize the substrate for catalytic activity. …

Urban Development In Costa Rica: The Direct And Indirect Impacts On Local And Regional Avian Assemblages, Jeff L. Norris

Dissertations

Urban development, the pinnacle of human land use, has drastic effects on native ecosystems and the species they contain. For the first time in recorded history there are more people living in cities than in the rural areas surrounding them. Furthermore, the global rate of urbanization continues increasing; raising serious concerns for earth's tropical regions as they harbor a disproportionate amount of the earth's species, and where the impacts of urban development on natural communities are poorly known. Therefore, for my dissertation research I investigated the impacts of urban development on avian community structure and organization at both local and …

Assembly Of The Didymium Iridis Mitochondrial Genome By Genome Walking, Dale Kopp

College of Science and Health Theses and Dissertations

Organelle inheritance and RNA editing has been studied in Didymium iridis even though the genome has not been completely sequenced. Four segments, comprising 66 kb, have been sequenced in the past. Several approaches have been taken to complete the sequence including restriction mapping and southern hybridization, as well as screening clone banks by PCR with the sequence of contig ends. In this study, genome walking was used to uncover sequences connecting the four segments. Using genome walking, approximately 4,113 bp of new sequence was identified. With the new sequence and the characterization of two previously sequenced D. iridis mt regions …

The Genetic Basis Of Cuticular Hydrocarbon Production In Drosophila Melanogaster And D. Simulans, Jessica A. Pardy

Electronic Thesis and Dissertation Repository

Individuals within many species have evolved complex reproductive strategies to ensure they identify appropriate mates so as to increase their fitness. Chemical signals, which are often species- and sex-specific, are one means by which many insect species communicate. Differences in cuticular hydrocarbons (CHCs) profiles can influence reproductive isolation in Drosophila. A previous study identified large genomic regions that contain genes responsible for the different CHC profiles observed in D. melanogaster and D. simulans females. I refined these earlier results by utilizing fine-scale mapping, focusing on the entire CHC profile, in an effort to determine which genes are responsible for …