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Full-Text Articles in Cell Biology

The Anti-Diabetic Drug Metformin Disrupts Feeding And Sleeping Behaviors In Drosophila Melanogaster., Lucas Fitzgerald May 2024

The Anti-Diabetic Drug Metformin Disrupts Feeding And Sleeping Behaviors In Drosophila Melanogaster., Lucas Fitzgerald

College of Arts & Sciences Senior Honors Theses

Dimethylbiguanide, also known as metformin, is the single most prescribed oral treatment for non-insulin dependent diabetes mellitus, or type 2 diabetes, in Western countries. The primary mechanism of action that metformin acts through is the activation of AMP kinase, an important regulator of energy homeostasis. While the anti-diabetic effects of metformin are well documented, its effects on feeding and sleeping behaviors are not well characterized. Using the model organism Drosophila melanogaster, the mean daily quantity of food consumed was measured and compared between groups treated with several dosages of metformin. Feeding interactions such as meal frequency and length were …


The Role Of Cort And Anaphase Promoting Complex/Cyclosome (Apc/C) In Drosophila Sex Determination And Meiosis, Abuzar Sikander Malik Jan 2023

The Role Of Cort And Anaphase Promoting Complex/Cyclosome (Apc/C) In Drosophila Sex Determination And Meiosis, Abuzar Sikander Malik

Electronic Theses and Dissertations

The E3 ubiquitin ligase, APC/C, is essential for the completion cell cycle; along with its co-activators it allows mitotic exit and maintenance of G1. APC/C marks various substrates with ubiquitin chains; marked substrates are subsequently destroyed via the 26S proteasome pathway. Cort is a Drosophila female meiosis specific activator of APC/C. Cort works within meiosis in conjunction with Fzy to mediate Securin and cyclin destruction. A C-terminal IR-tail motif and a N-terminal C-box support Cort-APC/C interaction, whereas short motifs like D-box and KEN-box on the target protein impart substrate recognition to Cort. Cort expression is tightly controlled in the female …


Unbiased Automated Quantitation Of Ros Signals In Live Retinal Neurons Of Drosophila Using Fiji/Imagej, Prajakta Deshpande, Neha Gogia, Anuradha Venkatakrishnan Chimata, Amit Singh Aug 2021

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, …


Actin Regulation And Furrow Dynamics During Early Drosophila Embryogenesis, Yi Xie Jan 2020

Actin Regulation And Furrow Dynamics During Early Drosophila Embryogenesis, Yi Xie

Electronic Theses and Dissertations

Drosophila embryogenesis starts with a single nucleus undergo 13 rounds of nuclear divisions called syncytial cycles. Staring at cycle 10 when nuclei migrate to the surface of the embryo, massive and dynamic cortical actin structures and cleavage furrow formations occur. How actin regulators coordinate into an organized network directing three-dimension actin structures in the developing organisms is an unsolved question. Here, I present an in-depth characterization of actin cap dynamics: the actin caps go through expansion, stabilization, elongation and fragmentation phases in each cycle. Arp2/3 is the major contributor to actin cap formation. The functions of 7 different actin and …


The Effect Of Ph On Synaptic Transmission At The Neuromuscular Junction In Drosophila Melanogaster, Catherine Elizabeth Stanley Jan 2020

The Effect Of Ph On Synaptic Transmission At The Neuromuscular Junction In Drosophila Melanogaster, Catherine Elizabeth Stanley

Theses and Dissertations--Biology

Synaptic transmission is the main avenue of neuronal communication and can be affected by a multitude of factors, both intracellularly and extracellularly. The effects of pH changes on synaptic transmission have been studied for many years across many different models. Intracellular acidification at the presynaptic terminal is known to occur with increased neuronal activity and can also occur in pathological conditions. The effects of these pH alterations are therefore an important area of study. Here, intracellular acidification using either propionic acid or the ammonium chloride pre-pulse technique was examined for the effects on both spontaneous and evoked synaptic transmission at …


Mechanisms Of Oriented Cell Division And Their Roles In Tissue Development, Evan Blake Dewey Apr 2019

Mechanisms Of Oriented Cell Division And Their Roles In Tissue Development, Evan Blake Dewey

Biology ETDs

Properly executed cell division is crucial to development, maintenance, and longevity of multicellular organisms. Defects in both symmetric and asymmetric divisions can lead to improper developmental patterning, as well as genomic instability, disruption of tissue homeostasis, and cancer. Our research focuses on how regulators orchestrate proper cell divisions. Mushroom Body Defect (Mud) is one such regulator, and here we describe how Mud is regulated via the Hippo signaling pathway kinase Warts (Wts), showing Wts phosphorylates Mud to enhance interaction with the polarity protein Partner of Inscuteable, promoting spindle orientation activity. We next focus on another regulator, Shortstop (Shot), describing a …


The Effects Of A Ketone Body On Synaptic Transmission, Alexandra Elizabeth Stanback Jan 2019

The Effects Of A Ketone Body On Synaptic Transmission, Alexandra Elizabeth Stanback

Theses and Dissertations--Biology

The ketogenic diet is commonly used to control epilepsy, especially in cases when medications cannot. The diet typically consists of high fat, low carb, and adequate protein and produces a metabolite called acetoacetate. Seizure activity is characterized by glutamate excitotoxicity and therefore glutamate regulation is a point of research for control of these disorders. Acetoacetate is heavily implicated as the primary molecule responsible for decreasing glutamate in the synapse; it is believed that acetoacetate interferes with the transport of glutamate into the synaptic vesicles. The effects on synaptic transmission at glutamatergic synapses was studied in relation to the ketogenic diet …


Polyglutamine Repeat Proteins Disrupt Actin Structure In Drosophila Photoreceptors., Annie Vu, Tyler Humphries, Sean Vogel, Adam Haberman Dec 2018

Polyglutamine Repeat Proteins Disrupt Actin Structure In Drosophila Photoreceptors., Annie Vu, Tyler Humphries, Sean Vogel, Adam Haberman

Biology: Faculty Scholarship

Expansions of polygutamine-encoding stretches in several genes cause neurodegenerative disorders including Huntington's Disease and Spinocerebellar Ataxia type 3. Expression of the human disease alleles in Drosophila melanogaster neurons recapitulates cellular features of these disorders, and has therefore been used to model the cell biology of these diseases. Here, we show that polyglutamine disease alleles expressed in Drosophila photoreceptors disrupt actin structure at rhabdomeres, as other groups have shown they do in Drosophila and mammalian dendrites. We show this actin regulatory pathway works through the small G protein Rac and the actin nucleating protein Form3. We also find that Form3 has …


Regulation Of Epithelial Proliferation And Migration By Apical-Basal Polarity Proteins, Gregory Vincent Schimizzi May 2018

Regulation Of Epithelial Proliferation And Migration By Apical-Basal Polarity Proteins, Gregory Vincent Schimizzi

Arts & Sciences Electronic Theses and Dissertations

Epithelial cells line all the outside surfaces of the body where they perform essential roles in maintaining homeostasis. In addition, epithelial tissues are implicated in many disease processes and are the most common tissue type to give rise to human cancer. Therefore, a thorough understanding of epithelial development and homeostasis has broad implications for understanding human development, health, and disease. The establishment and maintenance of apical-basal polarity is a defining characteristic and essential feature of functioning epithelia. Proper apical-basal polarity (ABP) is required for epithelial tissues to carry out their functions, which include absorption, secretion, barrier formation, and collective migration. …


Impact Of Ros Presence On Oncogenic Ras Activity, Chris Andersen Jan 2018

Impact Of Ros Presence On Oncogenic Ras Activity, Chris Andersen

Summer Research

Previous research has suggested a connection between oncogenic Ras and the cell’s levels of Reactive Oxygen Species (ROS). The underlying cellular mechanism is not well understood. To investigate this connection, we applied the UAS-GAL4 system in Drosophila melanogaster flies to control the expression of Ras and Keap1, a key redox regulator.2 We expected the activity of Ras to vary with its redox environment and thus impact protein activity downstream of Ras signaling cascades. In monitoring three proteins downstream of Ras—Dcp-1, Akt, and MAPK—we aimed to determine which pathways were impacted by ROS modulation.


Cellular/Molecular Analysis Of Interspecies Sterile Male Hybrids In Drosophila, Rachelle L. Kanippayoor Jun 2017

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 …


Characterization Of Histidine Decarboxylase In Drosophila Using An Internal Flag Epitope, Maxwell Mianecki Dec 2014

Characterization Of Histidine Decarboxylase In Drosophila Using An Internal Flag Epitope, Maxwell Mianecki

Masters Theses

Histamine is a neurotransmitter in arthropods and is responsible for synaptic transmission in vision, mechanosensation, temperature sensing and sleep cycle in Drosophila. Histamine is synthesized by the enzyme histidine decarboxylase (HDC). While histamine is detectable within tissues using current immunofluorescent labeling techniques, immunological approaches have not been successful for HDC itself, with both direct antibodies and terminal epitope tags determined to be ineffective. In order to avoid loss of the epitope tag through putative N-­‐ and C-­‐terminal proteolytic cleavage, known to occur for HDC in other organisms, an internal epitope tag that does not disrupt enzyme function was utilized. A …


Astrocyte-Specific Regulation Of Hmecp2 Expression In Drosophila, David Hess-Homeier, Chia-Yu Fan, Tarun Gupta, Ann-Shyn Chiang, Sarah J. Certel Oct 2014

Astrocyte-Specific Regulation Of Hmecp2 Expression In Drosophila, David Hess-Homeier, Chia-Yu Fan, Tarun Gupta, Ann-Shyn Chiang, Sarah J. Certel

Biological Sciences Faculty Publications

Alterations in the expression of Methyl-CpG-binding protein 2 (MeCP2) either by mutations or gene duplication leads to a wide spectrum of neurodevelopmental disorders including Rett Syndrome and MeCP2 duplication disorder. Common features of Rett Syndrome (RTT), MeCP2 duplication disorder, and neuropsychiatric disorders indicate that even moderate changes in MeCP2 protein levels result in functional and structural cell abnormalities. In this study, we investigated two areas of MeCP2 pathophysiology using Drosophila as a model system: the effects of MeCP2 glial gain-of-function activity on circuits controlling sleep behavior, and the cell-type specific regulation of MeCP2 expression. In this study, we first examined …


Examining The Functional Role Of Dprl-1 In Drosophila Melanogaster, John Valenzuela Jan 2013

Examining The Functional Role Of Dprl-1 In Drosophila Melanogaster, John Valenzuela

Summer Research

The Phosphatase of Regenerating Liver (PRL) family of proteins control cell growth, motility and proliferation. They have been shown to elevate the levels of these functions, leading to an increase in cancer metastasis (“malignancy”), when they are overexpressed. The goal of this experiment is to knockout PRL gene expression to examine the general function of PRL proteins. Drosophila melanogaster have only one copy of the PRL gene (dPRL-1), as opposed to humans and other mammals, which have 3. Thus, using P-element imprecise excision to create mutant strains either fully lacking or with decreased function of the dPRL-1 protein, …


Target Recognition And Competitive Synaptogenesis In The Drosophila Giant Fiber System, Jason Joseph Hill May 2012

Target Recognition And Competitive Synaptogenesis In The Drosophila Giant Fiber System, Jason Joseph Hill

Open Access Dissertations

The development of complex neural networks relies on a careful balance of environmental cues to guide and shape both ends of the eventual connection. However, the correct wiring of circuits whose components share molecular profiles depends on a more elaborate phenomenon, competition. Despite being highly studied, there is still a lack of understanding as to the mechanism that allows molecularly identical cells to form exclusive connections with their targets. To address this complex question, we turned to a simple circuit within the genetically tractable fly. Responsible for the escape reflex, the Giant Fiber System is comprised of bilaterally symmetrical axons …