Life Sciences Commons^™

Characterizing The Expression Pattern And Function Of Tartan During Drosophila Development, Alaina Baggett

Biomedical Engineering Undergraduate Honors Theses

The development of complex structures and organs by multicellular organisms relies on the ability of epithelial cells to self-organize. Epithelia are sheets of connected cells, and compartment boundaries are formed between certain epithelial cells to create distinct tissue compartments. Compartment boundaries are specialized cell-cell interfaces that are enriched for the cytoskeletal proteins actin and myosin, leading to straight cell edges under relatively high tension that act as fences keep cells from moving between compartments. In the model organism Drosophila melanogaster (fruit fly), compartment boundaries in the early embryo are established in response to the non-uniform striped expression of the cell-surface …

Mutations In The N-Terminus Of The Mod(Mdg4) Btb Domain Reveal An Unexpected Role Of Mod(Mdg4) In Chromosome Segregation In Female Meiosis, Gwyneth D E Walker, Bruce D. Mckee

Chancellor’s Honors Program Projects

No abstract provided.

Unbiased Automated Quantitation Of Ros Signals In Live Retinal Neurons Of Drosophila Using Fiji/Imagej, Prajakta Deshpande, Neha Gogia, Anuradha Venkatakrishnan Chimata, Amit Singh

Biology Faculty Publications

Numerous imaging modules are utilized to study changes that occur during cellular processes. Besides qualitative (immunohistochemical) or semiquantitative (Western blot) approaches, direct quantitation method(s) for detecting and analyzing signal intensities for disease(s) biomarkers are lacking. Thus, there is a need to develop method(s) to quantitate specific signals and eliminate noise during live tissue imaging. An increase in reactive oxygen species (ROS) such as superoxide (O2•-) radicals results in oxidative damage of biomolecules, which leads to oxidative stress. This can be detected by dihydroethidium staining in live tissue(s), which does not rely on fixation and helps prevent stress on tissues. However, …

The Receptor Basis Of Serotonergic Modulation In An Olfactory Network, Tyler Ryan Sizemore

Graduate Theses, Dissertations, and Problem Reports

Neuromodulation is a nearly ubiquitous process that endows the nervous system with the capacity to alter neural function at every level (synaptic, circuit, network, etc.) without necessarily adding new neurons. Through the actions of neuromodulators, the existing neural circuitry can be adaptively tuned to achieve flexible network output and similarly dynamic behavioral output. However, despite their near ubiquity in all sensory modalities, the mechanisms underlying neuromodulation of sensory processing remain poorly understood. In this dissertation, I address three main questions regarding the mechanisms of one modulator (serotonin) within one sensory modality (olfaction). I begin by establishing a "functional atlas" of …

Functional Genetic Approaches To Provide Evidence For The Role Of Toolkit Genes In The Evolution Of Complex Color Patterns In Drosophila Guttifera, Mujeeb Olushola Shittu

Dissertations, Master's Theses and Master's Reports

Toolkit genes are set of genes that orchestrate the development of basic body plan of animals, and they are highly conserved in all animals. The co-option of the toolkit genes into the pigmentation pathway has led to the evolution of novel species. This study focuses on understanding how the complex color patterns in animals develop by using the Drosophila species in the quinaria group as models. We developed an mRNA in situ hybridization (ISH) protocol, which allowed us to study gene expression patterns in the abdomen of developing pupae of non-model Drosophila species (Chapter 2). Through ISH, we found that …

Determining The Genetic Control Of Neural Tube Malformation Through Genetic Interactions With Idgf3, Elli N. Fox

Honors Projects

Genetic mutations disrupting human neural tube formation can lead to birth defects such as spina bifida and anencephaly. Defects can result in lack of neural tube closure in either the caudal (spina bifida) or cranial (anencephaly) regions. Little is known about the genes that cause these malformations. Researchers have been using the model organism Drosophila melanogaster in an attempt to determine genes responsible for neural tube malformations. Recently, an ortholog of human chitin-like protein, imaginal disc growth factor 3 (Idgf3), has been identified as important in the proper formation of Drosophila egg dorsal appendages. However, the molecular mechanism responsible for …

Mef2-Bound Genes May Influence Ethanol Sedation In Drosophila Melanogaster, Katlyn M. Myers

Theses and Dissertations

Alcohol Use Disorder (AUD) is a global health issue that affects millions of people every year. This disorder has serious negative mental and physical consequences. Currently, treatment options for this disorder are largely limited to psychological therapy, with very few medications available to treat it. Being able to identify the environmental and genetic components that influence AUD can help improve diagnosis and treatment options. Previous studies in humans have shown a link between initial sensitivity and risk for alcohol abuse. Our laboratory uses Drosophila melanogaster as a model to study the genetic and environmental components of alcohol-related behaviors. Previous lab …

The Fruitless Gene Influences Female Mate Preference In Drosophila, Tabashir A. Chowdhury

Electronic Thesis and Dissertation Repository

Species can arise as a result of reproductive barriers that prevent gene flow between diverging populations that force them to remain isolated from one another. Behavioural isolation is one of the earliest acting reproductive barriers determined by the evolution of mating preferences that prevent inter-specific matings. Several traits have been identified that contribute to behavioural isolation, but the genetic basis of interspecific female preference is yet to be determined. I used genetic mapping techniques to identify and confirm that the fruitless gene is affecting species-specific female rejection of interspecies males, contributing to the behavioural isolation between Drosophila melanogaster and D. …

Dietary Restriction Enhances Circadian Amplitude And Delays Visual Decline By A Clock-Driven Increase In Phototransduction, Geoff Meyerhof

Natural Sciences and Mathematics | Biological Sciences Master's Theses

Aging is accompanied by a progressive loss of circadian rhythms. Lifespan-extending dietary paradigms such as dietary restriction (DR) enhance circadian amplitude and appear to extend lifespan in a clock-dependent fashion. However, the mechanisms by which DR amplifies circadian rhythms and why circadian rhythms decline with age have yet to be fully elucidated. Here we find that DR amplifies circadian amplitude by enhancing light sensitivity in the eye. We performed a circadian mRNA microarray in flies (Drosophila melanogaster) reared on DR or a high nutrient diet and found that DR increases the number of circadian transcripts and selectively amplifies the …

Genetic And Environmental Factors Influence Drosophila Ethanol Sedation, Rebecca E. Schmitt

Theses and Dissertations

Alcohol use disorder is a global health issue that affects a significant portion of the population, with affects including both negative mental and physical consequences. Currently, there are few treatment options available to those who suffer from alcohol use disorder, alcohol abuse, or alcohol dependence. Identifying candidate genes or environmental influences would therefore improve the means for possible treatments or identification of those people at risk for alcohol use disorder. Previous studies in humans have demonstrated an inverse association between initial sensitivity and risk for alcohol abuse. This connection allows investigators, and our laboratory, to investigate genetic and environmental factors …

Investigation For Novel Anti-Apoptotic Factors In The Neurons Of Drosophila Melanogaster, Haylie Rachel Lam

Chancellor’s Honors Program Projects

No abstract provided.

Using Crispr To Induce A Knock-Out Of Dprl-1 In Drosophila Melanogaster, Alicia Walker

Summer Research

Phosphatase of regenerating liver (PRL) is a protein that controls cell processes such as growth and division which has unknown targets. PRL has been found to have both oncogenic and tumor suppressive properties. This study aimed to create a knock out of PRL in Drosohpila melanogaster in order to assess its role in development and in order to illuminate its activity when it is expressed in cancers. We hypothesize that dPRL-1 plays an important role in embryogenesis and that the progeny which lack this gene will be unviable. The CRISPR/Cas9 system was selected as the method in which to create …

Cellular/Molecular Analysis Of Interspecies Sterile Male Hybrids In Drosophila, Rachelle L. Kanippayoor

Electronic Thesis and Dissertation Repository

Over time, genetic differences can accumulate between populations that are geographically separated. This genetic divergence can lead to the evolution of reproductive isolating mechanisms that reduce gene flow between the populations and, upon secondary contact, result in distinct species. The process of speciation is, thus, what accounts for the multitude of species that contribute to the rich biodiversity on Earth. Interspecies hybrid sterility is a postzygotic isolating mechanism that affects the development of hybrids, rendering them sterile. A notable trend, known as Haldane's Rule, describes that heterogametic individual (e.g. males in Drosophila) are more susceptible to sterility than homogametic …

A Genetic Analysis Of Nuclear Functions Of The Lipin Protein In Drosophila Melanogaster, Xeniya Rudolf

Graduate Theses and Dissertations

Lipins are a family of proteins that have critical functions in the control of fat storage and energy homeostasis. Biochemically, lipins have two functions. They provide an enzymatic activity (phosphatidate phosphatase or PAP activity) in the glycerol-3 phosphate pathway that leads to the production of storage fats (triacylglycerols). In addition, they play a role in the regulation of genes in the cell nucleus as transcriptional co-regulators. The PAP activity of lipins has been widely studied in a number of organisms. However, the transcriptional co-regulator function is not as well described in the literature. The transcriptional function of lipins depends on …

Functional Significance Of Branch Points In Mirtrons, Britton A. Strickland

Honors Theses

MicroRNAs are a heterogeneous group of small regulatory RNAs generated by many pathways. Mirtrons (miR) are a class of microRNAs produced by splicing, and some mirtrons contain a 3’ tail located downstream from the self-complementary hairpin. During RNA splicing, a loop-like “lariat” intermediate structure is created when the 5’ end of the RNA is attached to an adenine called the branch point. The goal of this project is to uncover the contribution of branch point location to the processing of tailed mirtrons into functional gene regulators. This project approaches this issue from two directions. First, branch points were identified by …

Characterization Of Vesicular Monoamine Transporter 2 And Its Role In Parkinson's Disease Pathogenesis Using Drosophila, Antonio Joel Tito Jr., Sheng Zhang

Dissertations & Theses (Open Access)

Parkinson’s disease (PD) is a progressive neurodegenerative disorder caused by the selective loss of the dopaminergic neurons in the Substantia nigra pars compacta region of the brain. PD is also the most common neurodegenerative disorder and the second most common movement disorder. PD patients exhibit the cardinal symptoms, including tremor of the extremities, rigidity, slowness of movement, and postural instability, after 70-80% of DA neurons degenerate. It is, therefore, imperative to elucidate the underlying mechanisms involved in the selective degeneration of DA neurons. Although increasing numbers of PD genes have been identified, why these largely widely expressed genes induce …

Reverse Genetic Screening Of Innexin Gap Junction Proteins In Drosophila Neurons, Shannon P. Fox

Senior Honors Projects, 2010-2019

The reflexive response and perception of pain (nociception) is an evolutionarily conserved process in animals. Pain can be a major health concern and current treatments often prove insufficient, especially in regards to chronic pain. Greater understanding of the molecular processes underlying pain sensation could lead to new and more effective treatments. The aim of this study is to investigate the molecular mechanisms of cold nociception in Drosophila melanogaster. A specific subset of peripheral sensory neurons (Class III dendritic arborization (da) neurons), are implicated in Drosophila larvae’s response to noxious cold.

Previous literature has associated a family of gap junction protein, …

Drosophila Let-7 Microrna Is Required For Remodeling Of The Neuromusculature During Metamorphosis, Nicholas S. Sokol, Peizhang Xu, Yuh-Nung Jan, Victor R. Ambros

Victor R. Ambros

The Drosophila let-7-Complex (let-7-C) is a polycistronic locus encoding three ancient microRNAs: let-7, miR-100, and fly lin-4 (miR-125). We find that the let-7-C locus is principally expressed in the pupal and adult neuromusculature. let-7-C knockout flies appear normal externally but display defects in adult behaviors (e.g., flight, motility, and fertility) as well as clear juvenile features in their neuromusculature. We find that the function of let-7-C to ensure the appropriate remodeling of the abdominal neuromusculature during the larval-to-adult transition is carried out predominantly by let-7 alone. This heterochronic role of let-7 is likely just one of the ways in which …

The Effect Of Serrate Transmembrane Domain Substitution On Notch Signaling, James Z. Curlin

Senior Theses and Projects

The Notch signaling pathway is a crucial means by which organisms differentiate cells during development. Notch is regulated primarily through the interaction of a Notch receptor protein and a ligand protein, in two specific ways. Cis-inhibition occurs when both a ligand and receptor are present on the same cellular membrane. This results in the cis-ligand binding to the receptor and preventing the ligand on an adjacent cell from binding and activating the receptor. Alternatively, trans-activation occurs when the ligand and receptor are on adjacent cells, and results in the activation of the Notch pathway. Both the receptor …

The Role Of Ecdysone Signaling In Fat-Body Tissue Remodeling And Pupal Metabolism, Nichole Dinell Bond

UNLV Theses, Dissertations, Professional Papers, and Capstones

Holometabolous insects undergo an astonishing transition during their development. During metamorphosis, the larva dramatically changes form and becomes an adult fly. During this process obsolete larval tissues must be eliminated, while tissues required for further development are retained and often remodeled to meet the needs of the adult fly. Tissue remodeling is characterized by morphological changes of the cells in a tissue mass. In many cases, remodeling is characterized by dissociation of the tissue mass, releasing cells to move freely around the body cavity. This process is also common in wound healing and is a key feature of human disease …

Drawing Lines In The Sand: Even Skipped Et Al. And Parasegment Boundaries., James B. Jaynes, Miki Fujioka

Department of Biochemistry and Molecular Biology Faculty Papers

The pair-rule segmentation gene even skipped (eve) is required to activate engrailed stripes and to organize odd-numbered parasegments (PSs). The protein product Eve has been shown to be an active repressor of transcription, and recent models for Eve function suggest that activation of engrailed is indirect, but these models have not been fully tested. Here we identify the forkhead domain transcription factor Sloppy-paired as the key intermediate in the initial activation of engrailed by Eve in odd-numbered parasegments. We also analyze the roles of the transcription factors Runt and Odd-skipped in this process. Detailed analysis of engrailed and pair-rule gene …