Digital Commons Network^™

Crowd Control: Regulating The Spatial Organization Of Biopolymers And Gene Expression By Macromolecular Crowding, Gaurav Chauhan

Doctoral Dissertations

The intracellular environment is crowded with macromolecules that can occupy a significant fraction of the cellular volume. This can give rise to attractive depletion interactions that impact the conformations and interactions of biopolymers, as well as their interactions with confining surfaces. We used computer simulations to study the effects of crowding on biologically-inspired models of polymers. We showed that crowding can lead to attractive interactions between two flexible ring polymers, and we further characterized the adsorption of both flexible and semiflexible polymers onto confining surfaces. These results indicate that crowding-induced depletion interactions could play a role in the spatial organization …

Developmental Regulation Of Sirtuin Genes In Broiler Chicks, Heather L. Winter

Chancellor’s Honors Program Projects

No abstract provided.

Morphological And Gene Expression Plasticity In Neotropical Cichlid Fishes, Sharon Fern Clemmensen

Doctoral Dissertations

Trophic divergence in cichlid fish is linked to morphological shifts in the pharyngeal jaw apparatus. For instance, in the Heroine cichlids of Central America, the ability to crush hard-shelled mollusks is a convergent phenotype with multiple evolutionary origins. These durophagous species often have very similar pharyngeal jaw morphologies associated with the pharyngeal jaw apparatus and some of these similarities could be due to phenotypically plastic responses to mechanical stress. I examined the durophagous cichlid Vieja maculicauda for differences in pharyngeal osteology, dentition, and soft tissues when exposed to different diet regimes. Here I discuss the effect on the morphology and …

Spatial Crowding And Confinement Effects On Bursty Gene Expression, Charles Wei-Shing Chin

Doctoral Dissertations

Synthetic biology and genetic engineering are valuable tools in the development of new, sustainable energy generation technologies. The characterization of stochastic gene expression is vital to the efficient application of genetic engineering techniques. Transcriptional bursting, in which periods of high expression are punctuated by periods of no expression, is extensively observed in gene expression. While various molecular mechanisms have been hypothesized to be responsible for transcriptional bursting, spatial considerations have largely been neglected. This work uses computational modeling to examine in detail the influence of spatial factors such as macromolecular crowding and confinement on gene expression.

In the first part …

Feeding State, Vitamin A Status And Atypical Protein Kinase C Modulate The Insulin-Regulated Gene Expression In Rat Hepatocytes, Wei Chen

Doctoral Dissertations

Hormonal and nutritional stimuli coordinately regulate the glucose and lipid metabolism in the liver. Dysregulated hormonal balance and nutrient metabolism not only disrupt the energy homeostasis, but also predispose individuals to the development of obesity and its related metabolic diseases. Research presented in this dissertation investigated the effects of a nutritional factor, vitamin A (VA), and a potential component of insulin signaling cascade, atypical protein kinase C (aPKC), on the glucose and lipid metabolic genes transcription in primary hepatocytes from Zucker lean (ZL) and fatty (ZF) rats.

To examine VA effects, we put ZL and ZF rats with different VA …

Sublethal Toxicity Of Microcystis And Microcystin-Lr In Fish, Emily Dawn Rogers

Doctoral Dissertations

The occurrence of blooms of toxic cyanobacteria in freshwater environments is a global ecological and public health concern. Species of Microcystis are of particular importance because blooms occur in many freshwater environments throughout the world and microcystin toxin concentrations can exceed World Health Organization advisory levels. While microcystin has been associated with fish kills, sublethal effects of chronic exposure at environmentally relevant concentrations are relatively unknown. The objective of this research was to evaluate toxicity of microcystin and Microcystis in fish during all life history stages. We evaluated global gene expression response in larval zebrafish (Danio rerio), and …