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Seasonal Variation In Mitochondrial Bioenergetics Of The Bluegill Sunfish, Lepomis Macrochirus, From A Shallow Midwest River, Derick Isaac Lamptey

Masters Theses

As average global temperature increase, the frequency and magnitude of extreme temperatures in shallow aquatic ecosystems are more ubiquitous. In order to understand how these changing thermal regimes affect aquatic ectotherms, it is essential to develop studies evaluating the response of ectotherms to seasonal fluctuating thermal regimes. Previous studies on fluctuating temperature regimes have reported an increased physiological stress leading to morphological, behavioral and biochemical adaptations. From the latter, the adaptive capacity and seasonal performance associated with optimal function of the oxidative phosphorylation system (OXPHOS) are key for species persistence. However, studies on this matter are scarce. This study explores …

Investigation Of Glutamate Carboxypeptidase Ii Roles In The Folate Cycle Dependent Reproduction And Development Of Caenorhabditis Elegans, Jessica M. Derham

Masters Theses

Glutamate Carboxypeptidase II (GCPII) is a transmembrane, zinc metallopeptidase that is expressed in a wide range of organisms, including roundworms, mice, and humans. In humans, GCPII is primarily expressed in the prostate, kidneys, small intestine, and central nervous system. Within the small intestine, the expected function of GCPII is to aid in the absorption of dietary folate from the intestinal lumen. GCPII cleaves excess glutamates from folate to yield monoglutamated folate which is then readily transported into the enterocyte. Folate can then be used through the one carbon metabolic cycle for the synthesis of nucleotides, conversion of homocysteine to methionine, …

Design, Synthesis, And Characterization Of Chemical Tools To Study Peroxisomal Import, Jhalak N. Timilsena

Masters Theses

Peroxisomes are dynamic and interconnected single lipid membrane bound organelles found in the eukaryotic cells which are involved in various biochemical processes including the b-oxidation of very long chain and branched chain fatty acids, metabolism of reactive oxygen and nitrogen species, and reduction of hydrogen peroxide among others. These organelles are known to host numerous proteins and enzymes depending on the cellular environment. All of the proteins needed in the peroxisomes are encoded in the nucleus and synthesized in the cytosol which are then transported to the peroxisomes with the help of a sophisticated protein-transport machinery. Pex5 is one of …

Reprograming Neuronal Cells By Overexpression Of Fibroblast-Specific Transcription Factors, Abdulmohsen Alanazi

Masters Theses

In mammals, a complex system of regulatory signals distinguishes tissues, structures and functions. Combinations of transcription factors and co-factors regulate activation and repression of genes that result in cellular differentiation. Whole genome arrays allow the monitoring of genomic expression in specific tissues. Fibroblast microarray studies have shown candidate genes that may be involved in fibroblast identification, including genes that express transcription factors Prrx1, Snai2 and Twist1. A previous study showed that the Prrx1 and Snai2 could reactivate a fibroblast phenotype in hybrid cells that had lost fibroblast identity. Furthermore, overexpression of these factors in liver-derived cells strongly repressed liver gene …

Xylan Metabolism By Caulobacter Crescentus, Viet Bui

Masters Theses

Bacteria present unique opportunities to explore the molecular mechanisms of nutrient acquisition processes at single cell level under various experimental conditions. Caulobacter crescentus is a gram-negative oligotrophic environmental bacterium with adaptive physiological responses, such as slow growth or complete arrest of cell cycle, presence of sessile and motile progenies with the sessile cells growing stalk to enhance nutrient uptake for growth in low-nutrient conditions. Details of plant polysaccharide-derived carbon compound, such as cellobiose, maltose, and xylose utilization by C. crescentus can be found but molecular details or mechanisms of polysaccharide utilization, such as xylan, has not been reported. Database analyses …

Reprogramming Of Rat Hepatoma Cells With Fibroblast-Specific Protein Twist1, Kezban Ucar Cifci

Masters Theses

In mammalian development, a complex system comprised of regulatory signals causes tissue distinction with unique structures as well as functions. Gene expression controls these functions through specific combinations of transcription factors and cofactors that influence cell differentiation by both activation and repression of genes.

Whole genome microarray studies of fibroblasts have identified candidate genes that can serve as master regulators of fibroblast identity. A previous study showed that Prrx1 and Snai2 play important roles in activating expression of fibroblast identity, and Snai2 overexpression in hepatoma cells (Fg14) activated expression of fibroblast specific genes. Moreover, Snai2 overexpression resulted in repression of …

The Role Of Prrx1 And Snai2 As Master Regulators Of Fibroblast Identity, Huda A. Alzahrani

Masters Theses

Mammalian development involves a complex system of regulatory signals and reactions, leading to the creation of distinct tissues with specific structures and functions controlled by various gene expression profiles. Tissue-specific gene expression is by controlled specific combinations of transcription factors and cofactors that dictate cell differentiation via activation and repression of genes in mammalian cells.

Whole genome microarray analyses of fibroblasts have revealed candidate genes that may serve as master regulators of fibroblast identity, such as Prrx1 and Snai2, that activate downstream genes such as Bmp3, Twist, Shox2, Cfos, Slug, Sema3A, Spp1, and Col1a1. A previous study showed that Prrx1 …

The Role Of Creg1 As A Master Regulator Of Liver Function, Abdulrahman Siran Aldaghmi

Masters Theses

The liver is known as the chemical factory of the body because it performs a wide range of biochemical functions required for life. Since the liver has such an important role in regulation of normal physiological processes, liver diseases cause a high rate of morbidity and mortality. Therefore, understanding the mechanisms of liver development will shed light on the causes of liver disease. In this study, a cell line model that utilizes rat hepatoma cells (Fg14) and hepatoma variant cells (H11) was used to identify master regulators of liver gene expression. Whole genome expression studies identified the gene CREG1 (Cellular …

Metabolic And Morphologic Shifts In Neuro2a Cells Cultured In Galactose Medium, Leah Welker

Masters Theses

It has been observed that highly-proliferating cells, such as cancer cells, rely mainly on glycolysis for ATP production, regardless of presence of oxygen. This effect, however, can be reversed by changing the main energy substrate in the medium from glucose to galactose. The oxidation of galactose in glycolysis yields less net ATP, presumably forcing the cell into OXPHOS. This has been established in many cell lines, including HeLA, HepG2, and skeletal muscle cells. As of yet, this has not been reproduced in neuronal cells. Using Neuro2a, a murine neuroblastoma cell line, this study exposes neuronal cells to galactose medium, and …

Impact Of Transcription Factors On Fibroblast Specific Gene Silencing In Somatic Cell Hybrids, Tania Ray

Masters Theses

As totipotent cells differentiate to specific cell types in multicellular organisms, certain sets of genes are turned off (gene silencing/gene extinction) while others are turned on (gene activation). Cell type specific gene silencing and gene activation is the basis of cell differentiation. Somatic cell hybrids which are produced by fusing different types of somatic cells from two different tissues have been used as a valuable resource to discern the phenomenon of lineage- specific gene extinction. Identification of regulatory factors that mediate gene extinction in hybrids are key to understanding regulatory mechanisms that govern cell differentiation in a multicellular organism. Transcription …

Expression Of Artemia Lea Proteins In Drosophila Melanogaster Cells Using Multicistronic Vector Constructs, Kazi Nazrul Islam

Masters Theses

In nature several organisms exhibit anhydrobiosis, the outstanding feature to survive in extreme desiccation by entering into a state of dormancy known as diapause. The cyst of the brine shrimp Artemia franciscana shows anhydrobiosis by entering into a diapause phase. Previous studies showed a correlation between anhydrobiosis and expression of highly hydrophilic polypeptides termed late embryogenesis abundant (LEA) proteins. However, the precise molecular mechanisms of LEA proteins are still unknown. The presence of multiple LEA proteins in Artemia suggests that some of them might work together. Here, I aimed to express different combination of two LEA proteins from Artemia franciscana …

The Effects Of Solutes In The Cryopreservation Of Adherent Neuroblastoma (Neuro-2a) Cells, Trisha L. Bailey

Masters Theses

A simple method to cryopreserve adherent monolayers of neuronal cells is currently not available, but the development of this technique could facilitate numerous applications in the field of biomedical engineering, cell line development, and drug screening. However, complex tissues of some exceptional animals survive freezing in nature. These animals are known to accumulate several small molecular weight solutes prior to freezing. Following a similar strategy, we investigated the effects of osmolytes such as trehalose, proline, and sucrose as additives to the traditional cryoprotectant dimethyl sulfoxide (Me2SO) in modulating the cryopreservation outcome of mouse neuroblastoma (Neuro-2a) cells. Neuro-2a cells adhered to …

The Role Of Creg1 And Pitx1 As Master Regulators Of Liver Function, Anit Shah

Masters Theses

Development in mammals requires a complex array of positive and negative regulatory signals and responses. The liver is a major organ that has been studied extensively to understand underlying genetic processes responsible for specification, establishment and maintenance of tissue identity. Hepatoma and hepatoma variant cell lines have been used as a model to understand genetic networks responsible for liver function. Whole genome analysis of these cell types has identified candidate genes that might serve as master regulators of liver identity. In this study, the role of two candidate genes - cellular repressor of E1A stimulated gene (CREG1) and paired-liked homeodomain-1 …

Freeze Tolerance Conferred By Transgenic Expression Of Late Embryogenesis Abundant Protein In Insect Cells, Alyssa N. Walser

Masters Theses

Anhydrobiotic organisms such as the brine shrimp Artemia franciscana have developed strategies to survive and thrive under conditions of limited water availability. One strategy is the accumulation of late embryo genesis abundant (LEA) proteins. Cells of Drosophila melanogaster (Kc167), which had previously been genetically modified to express a group 1 LEA protein (LEA1.3) found in A. franciscana, were used to test the impact of water stress due to freezing to -80°C. Two different freezing devices were used to determine the impact of the freezing protocol on the viability of cells after freezing and thawing. The first method used a 12-well …

Molecular Mechanisms Involved In Anhydrobiosis Of Insect Cells, Diyagama Arachchi Ralalage Dilini Sewwandi Samarajeewa

Masters Theses

Animals possessing tolerance to extreme water stress are termed anhydrobiotes. Many desiccation tolerant organisms respond to water stress by intracellular accumulation of selected sugars such as trehalose and larger macromolecules such as Late Embryogenesis Abundant (LEA) proteins and thereby maintain the cell viability. Evidence indicates that the presence of trehalose and Late Embryogenesis Abundant (LEA) proteins may work synergistically to confer cellular protection during drying in eukaryotic cells. We evaluated any increase in cellular desiccation tolerance by expressing different LEA proteins in a non-desiccation tolerant insect cell line Drosophila melanogaster (fruit fly) (Kc167 cells) in the presence of trehalose.

Transgenic …

Desiccation Tolerance In Insect Cells, John Marcus Anderson

Masters Theses

In anhydrobiotic animals a reoccurring strategy to survive water stress involves the accumulation of low molecular weight solutes (e.g., trehalose) and highly hydrophilic macromolecules [e.g., late embryogenesis abundant (LEA) proteins]. We utilized two different water-stress models (spin-drying, and hyperosmotic dehydration) to investigate the impact of transgenic expression of a trehalose transporter [BT003466 (TRET)] and of a group 1 LEA protein [ACX81198 variant (LEA1)] on membrane integrity in cell lines from Spodoptera frugiperda (Sf-21) and Drosophila melanogaster (Kc167), respectively. Kc167 cells were challenged with sucrose or trehalose concentrations ranging from 0 to 200 mM supplemented in standard culture medium. Significant inhibition …

Histology Of Dichromatic And Seasonal Color Change Of The Cranial Region Of Callagur Borneoensis, Kevin William Matson

Masters Theses

Male Callagur borneoensis exihibit sexual dichromatism and seasonal coloration which is rare among turtles. In the breeding season male's heads are colored white with a scarlet stripe from the occiput to the tip of the snout. After the breeding season they change to drab charcoal-gray to black with a dull orange-yellow stripe. Females and juveniles are a drab brown throughout the year.

This study was performed to determine the mechanisms of this color change at the histological level. Histological preparation of the head revealed a significant increase in vascular tissue just below the epidermis of the stripe area with increased …

The Structure And Fate Of Germinal Plasm In The Asiatic Fire-Bellied Frog, Bombina Orientalis (Anura-Discoglossidae), Ted W. Odom

Masters Theses

Lehman's polychrome stain was used to follow the fate of germinal plasm in early development of Bombina orientalis embryos. Islets of germinal plasm approximately 6 um in diameter were observed in the vegetal pole region of the 2-cell embryo. By the 4-cell stage, some of these islets had coalesced to form larger ones so that two size classes of islets were present (approximately 7.5 and 19.5 um in diameter).

As cleavage continued to the 16-cell stage, the islets were moved further up the cleavage furrow and were always observed to remain in close association with the cleavage membrane. The islets …

A Histochemical Study Of Tooth Development In The Chinese Hamster (Cricetulus Griseus), Robert B. Daszkiewicz

Masters Theses

The normal morphological development of the Chinese hamster (Cricetulus griseus) during the last week of gestation was studied. A review of the literature reveals no distinct study of tooth development in this species. An identical gestation period is found in the mouse (Mus musculus) making direct comparison between the embryos of the same age of the two species feasible. During this investigation, it was found that morphological tooth development in the Chinese hamster lagged behind that of the mouse by about 2 days. On day 14 of gestation in the Chinese hamster, the oral epithelium is …

Cytological Investigations Of Eremosphaera Viridis De Bary, Richard Allen Valentino

Masters Theses

Eremosphaera viridis de Bary was studied with light microscope techniques to determine the method of cytokinesis and to explain the ontogeny of the membranous ring separating the mature daughter cells in the intact sporangium.

It is proposed that cytokinesis in this organism is phylogenetically advanced and that the separation of mature daughter cells involves the sequential deposition of two cell walls. The first wall develops centripetally by the addition of membrane subunits. The resulting cleavage furrow is oriented by transverse microtubules found along the cell division plane. The newly formed walls separate the two daughter cells and give rise to …

A Cytogenetic Study Of Xx/Xy Chimerism And Other Anomalies Of Bos Taurus In A Sampled Dairy Herd, Ferne M. Rogers

Masters Theses

The establishment of normal chromosomal patterns for a wide range of plants and animals has led to the recognition of abnormalities as well as their relationship to phenotypic irregularities. Research dealing with the expression of human karyotype is of prime interest; but, closely rivaling that is the genetic study of domestic animals which are of economic importance to man.

One observed anomaly which has come under scrutiny by cytogeneticists is that of the female member of a heterogeneous bovine twin pair, the freemartin. This is a sterile animal with internal morphology showing varying degrees of intersex. Cytogenetic studies reveal XX/XY …

Cytology Of Chaetomidium Fimeti, David D. Kimmel

Masters Theses

No abstract provided.

The Effect Of Caffeine On Pisum Sativum With Emphasis On Meiosis, Terese M. Mikottis

Masters Theses

No abstract provided.

The Morphology And Cytology Of Preussia Vulgare (Corda) Cain, Marcial Antonio Pastor-Corrales

Masters Theses

No abstract provided.

Studies On Muropeptide Amino Acids Of Rhizobium Japonicum, Mohammed Alauddin

Masters Theses

The isolation of Rhizobium japonicum cell walls was performed by ultrasonication and the enzymatic digestion with DNase, RNase and pronase separately. Crude cell walls were washed with M NaCl and 5% SDS and were isolated by 20,000 g centrifugation. Muropeptide amino acids were freed by hydrolysis at 121C for 10 minutes in 6N HCl.

Detection of Rhizobium japonicum murein layer amino acids was done by 2-dimensional instant thin layer chromatography on silica gel plates. The solvents found most favorable, were n-butanol: acetic acid: water and n-propanol: 34% ammonium hydroxide. Amino acid spots were developed by spraying ninhydrin on the chromatograms, …

The Effects Of Desoxycorticosterone, Hydrocortisone, And Prednisone On Myogenesis In Vitro, Gregory K. Nienaber

Masters Theses

In order to obtain proper muscle development in tissue culture, certain conditions must prevail. There is a delicate balance of factors, and elimination of even one of these factors leads to poor and improper development. Muscle cells grown in the absence of fibroblasts usually fail to differentiate. Therefore, proper development depends upon the presence of two cell types: myoblasts and fibroblasts. Investigators have demonstrated that the fibroblasts are necessary in that they produce collagen which is necessary for proper muscle development. The present study has shown that desoxycorticosterone, hydrocortisone, and prednisone at concentrations of 10, 1, and 0.1 ug/ml of …

Lysis Of The Rhizobiaceae, Craig Richard Baumrucker

Masters Theses

The following members of the Rhizobiaceae were tested for their lytic response to various treatments: Agrobacterium tumefaciens, Chromobacterium violaceum, Rhizobium phaseoli, Rhizobium trifolii, Rhizobium lupini, and Rhizobium japonicum. Lysis was observed in spent growth media and as a function of saline concentration, pH, buffer composition, disodium (ethylenedinitrilo) tetraacetate (EDTA) concentration, and lysozyme.

Cells were harvested by centrifugation, washed, and resuspended in various treatment solutions. The lytic response was followed spectrophotometrically.

The different responses of the six cultures was applied to a summation of reclassification proposals evolved through modern taxonomic techniques such as DNA homology …

A Histochemical Study Of The Ovary Of The Milkweed Bug Oncopeltus Fasciatus (Dallas), With Special Reference To The "Intermediate" Cell, Khian Kioe Liem

Masters Theses

No abstract provided.

Forelimb Regeneration Study In The Adult Small-Mouthed Salamander (Ambystoma Texanum), John Farrell Williams

Masters Theses

No abstract provided.

A Developmental Study Of The Endocarp Tissue In The Fruits Of Malus X Zumi And Crataegus Mollis, Two Representatives Of The Family Rosaceae, Subfamily Maliodeae, David Lee Haas

Masters Theses

No abstract provided.