Life Sciences Commons^™

Differential Gene Expression In Starvation Selected Drosophila Melanogaster, Katherine Schultz

UNLV Theses, Dissertations, Professional Papers, and Capstones

Fruit flies that have been selected for starvation resistance can be used in experimental studies to study physiological processes. Both their genomes and their phenotypes, especially metabolism, change significantly as a result of artificial selection. Starvation selected flies develop slower and are larger due to higher lipid content as adults. We used RNAseq to study gene expression in third instar larval fat body tissue from selected and control lines at the same chronological time point, when the fed control (“FC”) lines were wandering, and the starvation selected (“SS”) lines were in the third larval instar but not yet wandering due …

Rapid Evolution Of Starvation Resistance In Drosophila: Physiological And Molecular Mechanisms, Austin Joseph Mckenna

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Gibbs lab has maintained starvation-selected Drosophila melanogaster for >130 generations. These starvation-selected flies evolved an obese phenotype with a suite of physiological differences compared to control-fed flies. Previous studies have shown that long-term starvation-selected Drosophila contain more lipids, have lower metabolic rates and develop more slowly than controls. This dissertation encompasses 1) Examining the molecular mechanisms contributing to starvation resistance, 2) Functional validation of the candidate plin1 allele, and 3) Rapid physiological and genomic evolution in starvation-selected Drosophila.

Starvation-selected Drosophila survive starvation conditions much longer than control-fed flies. This study took a simple approach to identify possible differences in …

Gene Expression Profiling In The Larval Fat Body Of Desiccation Selected Drosophila Melanogaster, Adriana Michelle Charles

UNLV Theses, Dissertations, Professional Papers, and Capstones

Drosophila melanogaster selected for resistance to desiccation (no food or water) display slower development and a higher body mass compared to fed controls due to an extended third larval instar. I hypothesize that desiccation selected D. melanogaster larvae will have a different gene expression profile compared to fed controls. Separate populations of D. melanogaster were subjected to desiccation (no food or water), starvation (no food) until 80-85% mortality, for 75 generations. mRNA from the larval fat body was collected at 88 hours, 96 hours, 112 hours and 120 hours post-hatching. Four replicate samples were used for each condition and time …

Physiology And Genetics Of Starvation-Selected Drosophila Melanogaster, Christopher Michael Hardy

UNLV Theses, Dissertations, Professional Papers, and Capstones

In nature, organisms have evolved to survive in stressful environments. This has driven organisms to adopt a wide range of unique adaptations. Investigating the mechanistic basis of these adaptations is an important tool for discovery that has led to major advances in science and medicine.

We study how organisms survive life without food, or starvational stress. Environmental stressors have shaped the quantity and quality of food sources across the globe. This has led to vast differences in the ability of some organisms to tolerate starvation over others. Many researchers have used Drosophila melanogaster as a model to study global patterns …

The Effects Of Starvation Selection On Drosophila Melanogaster Life History And Development, Lauren A. Reynolds

UNLV Theses, Dissertations, Professional Papers, and Capstones

In nature, animals may endure periods of famine to complete their life cycles. Starvation stress will increase in populations as climates around the world change. To predict how populations may respond to such a stress, laboratory experimentation becomes essential. The evolutionary process of adaptation, its innovations and their trade-offs, can be studied in populations experiencing starvation stress. For this purpose outbred populations ofDrosophila melanogasterwere selected for starvation resistance in the laboratory.

After 60+ generations of starvation selection the starvation-selected flies have gone from surviving 2-3 days without food to 12-14 days without food. How this amazing feat of resistance is …

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 …