Life Sciences Commons^™

Effects Of Altering Physiologically Relevant Cholesterol Levels And Media Types On Porin Gene Expression In Klebsiella Pneumoniae And The Resulting Impact On Antibiotic Resistance, Megan R. Camden

UNF Graduate Theses and Dissertations

Klebsiella pneumoniae is a Gram-negative, non-motile bacterium belonging to the Enterobacteriaceae family. K. pneumoniae is a rising threat in the clinical setting, as there has been a large increase in the presence of antibiotic resistant isolates. While much research is conducted on laboratory and clinical strains of bacteria, not much is known regarding the impact that human physiology can have on bacterial gene expression, and in response, to antibiotic susceptibility. The goal of this study is to determine if physiologically relevant cholesterol levels and media types impact porin gene expression and antibiotic resistance in K. pneumoniae. To accomplish this, …

Functional Analysis Of Fam83d And Dupd1 – Two Novel Neruogenic Skeletal Muscle Atrophy-Induced Genes, Lisa Michelle Cooper

UNF Graduate Theses and Dissertations

Fam83d and Dupd1 have been identified as novel genes in skeletal muscle that are upregulated in response to neurogenic atrophy in a mouse model. qPCR analysis reveaed both genes are expressed in skeletal muscle with Fam83d expression being highest during myoblast proliferation, while Dupd1 expression is highest during myotube differentiation. Overexpression of either protein results in inhibition of proper muscle cell differentiation as evidenced by repression of both myosin heavy chain and myogenin expression. Characterization of transcriptional activity revealed both genes are modulated by myogenic regulatory factors and additionally, Dupd1 expression is enhanced by dexamethasone treatment. Assessment of subcellular localization …

Effects Of Aquatic Acidification On Calcium Uptake In White River Shrimp Litopenaeus Setiferus Gills, Maria-Flora Jacobs

UNF Graduate Theses and Dissertations

Previous research regarding aquatic acidification has examined the protonation of the carbonate and does not consider calcium to be a limiting factor. This is the first study to suggest that pH may affect the uptake of calcium in crustacean gills. This project describes ion transport mechanisms present in the cell membranes of white river shrimp Litopenaeus setiferus gill epithelium, and the effects of pH on the uptake of calcium by these means. Partially purified membrane vesicles (PPMV) of shrimp gills were prepared through a homogenization process that has been used previously to define ion transport in crab and lobster gill …

Estimating The Heritability Of Thermal Tolerance In Acropora Cervicornis And The Physiological Basis Of Adaptation That Correlates To Survival At Elevated Temperatures, Kelsey L. Yetsko

UNF Graduate Theses and Dissertations

Human activities have substantially increased the atmospheric concentrations of greenhouse gases, resulting in warmer ocean temperatures that are having a negative impact on reef corals, which are highly susceptible to changes in temperature. Understanding the degree to which species vary in their tolerance to elevated temperatures and whether this variation is heritable is important in determining their ability to adapt to climate change. In order to address this, Acropora cervicornis fragments from 20 genetically distinct colonies were kept at either ambient or elevated temperatures, and mortality was monitored for 26 days. Heritability of thermal tolerance was estimated using a clonal …

Functional Characterization Of A Novel Disaccharide Membrane Transporter In The Digestive Tract Of The American Lobster, Homarus Americanus, Olivia Scheffler

UNF Graduate Theses and Dissertations

In animals, the accepted model of carbohydrate digestion and absorption involves reduction of disaccharides into the simple sugars glucose, fructose and galactose. Previous studies have shown the presence of disaccharides maltose and trehalose in the blood of several crab species, the crayfish and the American lobster. In 2011, a gene for a distinct disaccharide sucrose transporter (SCRT) was first found in Drosophila melanogaster and characterized using a yeast expression system. The purpose of the current study was to identify and characterize a putative disaccharide transporter analog in crustaceans using the American lobster, Homarus americanus. Brush border membrane vesicles purified …

Molecular Identification And Functional Characteristics Of Peptide Transporter 1 (Pept1) In The Bonnethead Shark (Sphyrna Tiburo), Hannah Hart

UNF Graduate Theses and Dissertations

Many elasmobranchs are considered top predators with worldwide distribution, and in general these fish play an important role in the transfer of energy from the lower to the upper trophic levels within the marine ecosystem. Despite this, little research has been done regarding the rates of prey ingestion, digestion, and the processes of energy and nutrient absorption. Specifically understudied is enzymatic digestion within the intestinal brush border, which functions to break down macromolecules into smaller subunits for luminal absorption across the gastrointestinal epithelium. Given their carnivorous diet, the present study sought to expand knowledge on nutrient intake in elasmobranchs by …

Nutrient Transport By Shrimp Hepatopancreas, Tamla A. Simmons

UNF Graduate Theses and Dissertations

Purified brush border membrane vesicles (BBMV) were isolated to characterize primary cellular transport mechanisms for white shrimp. The ultimate goal is to determine the effective components of a shrimp’s diet, thereby enhancing growth, as well as nutrient content. Juvenile shrimp are dependent on plant material as a food source. Potassium is a key component of plants, thus it may play a role in nutrient transport. In addition, divalent metals have been shown to act as co-transporters in several other organisms, thus they may serve as a transport mechanism for shrimp.

Fresh, live, white or brown shrimp were obtained, and from …