Life Sciences Commons^™

Mob-Ndr Kinase Signaling Components Are Required For Epithelial Tube Formation In The Drosophila Follicular Epithelium, Juan Carlos Duhart

UNLV Theses, Dissertations, Professional Papers, and Capstones

A major goal of developmental biology is to understand how a single fertilized cell can give rise to the many functional tissues and organs, of specific sizes and shapes, that make up the adult body plan. Over the last 25 years, developmental geneticists have uncovered much concerning the cell-to-cell communication systems that are necessary to build complex tissues and organs. For example, throughout development, cells communicate with their neighbors using specialized signaling molecules. These signals are instructive and provide “signal-receiving” cells with information about space and time. That is, signal-receiving cells “learn” precisely where they are located, and, how far …

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 …

An Expanded Toolkit For Gene Tagging Based On Mimic And Scarless Crispr Tagging In, David Li-Kroeger, Oguz Kanca, Pei-Tseng Lee, Sierra Cowan, Michael T Lee, Manish Jaiswal, Jose Luis Salazar, Yuchun He, Zhongyuan Zuo, Hugo J Bellen

Faculty Publications

We generated two new genetic tools to efficiently tag genes in Drosophila. The first, Double Header (DH) utilizes intronic MiMIC/CRIMIC insertions to generate artificial exons for GFP mediated protein trapping or T2A-GAL4 gene trapping in vivo based on Cre recombinase to avoid embryo injections. DH significantly increases integration efficiency compared to previous strategies and faithfully reports the expression pattern of genes and proteins. The second technique targets genes lacking coding introns using a two-step cassette exchange. First, we replace the endogenous gene with an excisable compact dominant marker using CRISPR making a null allele. Second, the insertion is replaced …

The Acyl-Coa Synthetase, Pudgy, Promotes Sleep And Is Required For The Homeostatic Response To Sleep Deprivation, Matthew S. Thimgan, Natlie Kress, John Lisse, Courtney Fiebelman, Thomas Hilderbrand

Biological Sciences Faculty Research & Creative Works

The regulation of sleep and the response to sleep deprivation rely on multiple biochemical pathways. A critical connection is the link between sleep and metabolism. Metabolic changes can disrupt sleep, and conversely decreased sleep can alter the metabolic environment. There is building evidence that lipid metabolism, in particular, is a critical part of mounting the homeostatic response to sleep deprivation. We have evaluated an acyl-CoA synthetase, pudgy (pdgy), for its role in sleep and response to sleep deprivation. When pdgytranscript levels are decreased through transposable element disruption of the gene, mutant flies showed lower total sleep times …

Investigating The Role Of The Rough Deal Protein In Spindle Assembly Complex Signaling, Ryan P. Mihealsick

Chancellor’s Honors Program Projects

No abstract provided.

Blue Light Induces A Neuroprotective Open Access Gene Expression Program In Drosophila Photoreceptors, Hana Hall, Jingqun Ma, Sudhanshu Shekhar, Walter D. Leon-Salas, Vikki M. Weake

Department of Biochemistry Faculty Publications

Background: Light exposure induces oxidative stress, which contributes to ocular diseases of aging. Blue light provides a model for light‑induced oxidative stress, lipid peroxidation and retinal degeneration in Drosophila melanogaster. In contrast to mature adults, which undergo retinal degeneration when exposed to prolonged blue light, newly‑eclosed fies are resistant to blue light‑induced retinal degeneration. Here, we sought to characterize the gene expression programs induced by blue light in fies of diferent ages to identify neuroprotective pathways utilized by photoreceptors to cope with light‑induced oxidative stress.

Results: To identify gene expression changes induced by blue light exposure, we profled the nuclear …

Proper Splicing Contributes To Visual Function In The Aging Drosophila Eye, Rachel Stegeman, Hana Hall, Spencer E. Escobedo, Henry C. Chang, Vikki M. Weake

Department of Biochemistry Faculty Publications

Changes in splicing patterns are a characteristic of the aging transcriptome; however, it is unclear whether these age‐related changes in splicing facilitate the progressive functional decline that defines aging. In Drosophila, visual behavior declines with age and correlates with altered gene expression in photoreceptors, including downregulation of genes encoding splicing factors. Here, we characterized the significance of these age‐regulated splicing‐associated genes in both splicing and visual function. To do this, we identified differential splicing events in either the entire eye or photoreceptors of young and old flies. Intriguingly, aging photoreceptors show differential splicing of a large number of visual function …

Identification Of Raw As A Regulator Of Glial Development, Diana Luong, Luselena Perez, Jennifer Mierisch

Biology: Faculty Publications and Other Works

Glial cells perform numerous functions to support neuron development and function, including axon wrapping, formation of the blood brain barrier, and enhancement of synaptic transmission. We have identified a novel gene, raw, which functions in glia of the central and peripheral nervous systems in Drosophila. Reducing Raw levels in glia results in morphological defects in the brain and ventral nerve cord, as well as defects in neuron function, as revealed by decreased locomotion in crawling assays. Examination of the number of glia along peripheral nerves reveals a reduction in glial number upon raw knockdown. The reduced number of …

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. …

Egfr Polymorphisms In Drosophila Melanogaster, Stacie Chue, Neha Mehta, Samantha Poon, Heather Trazino

Publications and Research

No abstract provided.

Analysis Of Chromatin Interactions Of Beaf-Associated Promoters Using 4c, Shraddha Shrestha

LSU Doctoral Dissertations

A high degree of chromosome compaction is needed to fit nearly 2 meters of DNA inside a human nucleus of around 10 µm diameter. Correct chromatin folding is crucial to facilitate important nuclear functions such as transcription, DNA replication and DNA repair. Nuclei contain a variety of proteins, many of which help regulate chromatin structure and function. The mechanisms by which these proteins work are diverse and complicated. Here, we study the chromatin interactions of Boundary Element Associated Factor (BEAF) associated sites to gain insight into eukaryotic genome organization. We used circular chromosome conformation capture (4C) technology to detect genome-wide …

Disruption Of Rna Metabolism By Zika Virus, Maggie Lea Dickerson

Honors Theses

Flaviviruses are positive, single-stranded, enveloped RNA viruses that are a part of the family, Flaviviridae. West Nile virus, Dengue, Zika virus and more are a part of this family. Mosquitoes are the vectors for these viruses. In order for the virus to infect mosquitoes, it must evade the RNA interference (RNAi), which is the major antiviral immune mechanism of insects. One study found the 3’ untranslated region (UTR) of the West Nile virus that inhibited the RNAi (GP et al. 2016). The goal of this study is to investigate if the 3’ and 5’ UTR region of the Zika virus …

Evolutionary Conservation Of Midline Repulsion By Robo Family Receptors In Flies And Mice, Allison Loy

Biological Sciences Undergraduate Honors Theses

As the nervous system develops in animal embryos, neuronal axons are guided to their synaptic targets by extra cellular cues that signal through axon guidance receptors expressed on the surface of the axon. In animals with bilateral symmetry, one of the important decisions made by nearly every axon in the embryonic nervous system is whether to stay on its own side of the body, or to cross the midline and connect to cells on the opposite side. The Roundabout (Robo) family is an evolutionarily conserved group of axon guidance receptors that regulate midline crossing in a wide range of animal …

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

Chancellor’s Honors Program Projects

No abstract provided.

Comparative Meiotic Cytology Among Drosophila Species, Ahmed Folademi Majekodunmi

College of Science and Health Theses and Dissertations

Physical connections established by homologous recombination are normally sufficient to establish proper co-orientation of chromosomes during prometaphase of female meiosis I. Nonexchange chromosomes can still segregate because they are connected by heterochromatic threads, which are thought to connect homologous chromosomes and ensure co-orientation in the absence of a chiasma. In Drosophila, the nonexchange chromosomes (such as the Muller F element, also called the “dot chromosome,” which never undergoes recombination) move out on the spindle during prometaphase I, and can be found positioned between the spindle poles and the exchange chromosomes at the metaphase plate. By metaphase I arrest, these …

The Drosophilids Of A Pristine Old-Growth Northern Hardwood Forest, Thomas Werner

The Great Lakes Entomologist

The current study summarizes the results of a species inventory survey for drosophilid flies (family Drosophilidae, order Diptera) in a primeval forest in northern Michigan. The two main goals of the investigation were to list the species inhabiting the Huron Mountain Club and to collect live specimens for the illustrations in the book "Drosophilids of the Midwest and Northeast". From 2014 to 2016, I found 22 drosophilid species, which belong to the two subfamilies Steganinae and Drosophilinae. Future long-term studies are planned to test how the drosophilid populations respond to climate change.

Investigating Peroxiredoxins Impact On Amps, Noah Earland

SMU Journal of Undergraduate Research

The Orr-Radyuk lab is interested in understanding the link between aging and genetic influences controlling the cell’s redox state, as determined by enzymes involved in reducing and oxidizing (redox) reactions. They have observed that Drosophila normally exhibit a shift towards a pro-oxidizing cellular environment and spikes in AMP levels, independent of infections, when they reach old age. Additionally, peroxiredoxins (PRXs), a family of thiol-dependent peroxidases, have been shown to impact lifespan, and regulate the same pro-oxidizing shift seen in advanced age. Beyond their peroxidase functions, RXRs can also interact with signaling pathways related to immunity. Previous data showed that PRXs …

Modulation Of The Navigational Strategy Of Insects In Controlled Temperature Environments, Joseph Shomar, Anggie Ferrer, Josh Forer, Tom Zhang, Mason Klein

2018 Entries

With its small size and limited motor tool set, the Drosophila larva is a good system to study how animals alter specific elements of their behavior to search and reach optimal environmental conditions. We aim to understand the larva’s response to temperature across development, in sensory gradients, and to distinguish behavioral modulations based on physical changes from those due to sensory input. PID-controlled instruments drive temporal or spatial temperature gradients; combined with a moat system to replenish gels at high temperature, we can explore the larva’s full behavioral profile. Many larvae are simultaneously observed during free navigation in three different …

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.

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 …

In Vivo Structure-Function Analysis Of Drosophila Robo1, An Axon Guidance Receptor Critical For Midline Repulsive Signaling In The Embryonic Central Nervous System, Haley Brown

Graduate Theses and Dissertations

The repellant ligand Slit and its Roundabout (Robo) family receptors regulate many aspects of axon guidance in bilaterians, including midline crossing of axons during development of the embryonic CNS. Slit proteins are produced by midline cells and signal through Robo receptors expressed on the surface of axonal growth cones to repel axons from the midline. Disruption of Slit-Robo signaling causes ectopic midline crossing phenotypes in the CNS of a broad range of animals, including insects and vertebrates.

Drosophila Robo1 has a conserved ectodomain structure of five immunoglobulin-like (Ig) domains plus three fibronectin (FN) repeats. By utilizing a genomic rescue construct …

Collective Chemotaxis Of Retinal Neural Cells From Drosophila Melanogaster In Controlled Microenvironments, Stephanie Zhang

Dissertations and Theses

More than 172 million people are influenced by a retinal disorder that stems from either age-related or developmental causes. Of those, 1.5 million people endure a developmental retinal disorder. In the developing retina, neural cells undergo a series of highly complicated differentiation and migration process. A main cause of these diseases is abnormal collective migration of neural progenitors hindering the retinogenesis process. However, our grasp of collective migration and signaling molecules, critical to the developing retina, is incompletely understood. Understanding the molecular mechanisms, such as the fibroblast growth factor pathway, that regulate glial and neuronal migration provides decisive insights in …

Regulated Transcriptional Silencing Promotes Germline Stem Cell Differentiation In Drosophila Melanogaster, Pooja Flora

Legacy Theses & Dissertations (2009 - 2024)

Germ cells are the only cell in an organism that have the capacity to give rise to a new organism and are passed from one generation to the next. Therefore, to maintain this unique ability of totipotency and immortality, germ cells execute specific functions, such as, repression of a somatic program and contour a germ line-specific pre- and post-transcriptional gene regulatory landscape. In many sexually reproducing organisms, germ cells are formed during the earliest stages of embryogenesis and undergoes several stages of development to eventually get encapsulated by the somatic cells of the gonad. Once, in the gonad, the germ …

Chromatin-Signaling Axis Orchestrates The Formation Of Germline Stem Cell Differentiation Niche In Drosophila, Maitreyi Upadhyay

Legacy Theses & Dissertations (2009 - 2024)

Stem cells have the unique capability of self-renewing into stem cells and differentiating into several terminal cell types. Loss of either of these processes can lead to aging, progression towards degenerative diseases and cancers. Insight into how self-renewal and differentiation are regulated will have tremendous therapeutic impact. Drosophila is an excellent model system for stem cell study due to the availability of various mutants, markers and RNAi technology. In order to study stem cell biology, we use female Drosophila gonads, whose stem cell population – the germline stem cells (GSCs) gives rise to gametes.

Studies Of Norspermidine Uptake In Drosophila Suggest The Existence Of Multiple Polyamine Transport Pathways, Michael Dieffenbach

Honors Undergraduate Theses

Polyamines are a class of essential nutrients involved in many basic cellular processes such as gene expression, cell proliferation, and apoptosis. Without polyamines, cell growth is delayed or halted. Cancerous cells require an abundance of polyamines through a combination of synthesis and transport from the extracellular environment. An FDA-approved drug, D,L-α-difluoromethylornithine (DFMO), blocks polyamine synthesis but is ineffective at inhibiting cell growth due to polyamine transport. Thus, there is a need to develop drugs that inhibit polyamine transport to use in combination with DFMO. Surprisingly, little is known about the polyamine transport system in humans and other eukaryotes. Understanding the …

Jak/Stat Signaling Regulates Gametogenesis And Age-Related Reproductive Maintenance, Michelle Suzanne Giedt

Theses and Dissertations--Biology

Cell signaling is central to integration of internal and external cues that regulate development and homeostasis. Most development is thought of as pre-adult, but limited developmental processes occur in adults. Gametogenesis incorporates elements of both these facets, with a distinct developmental plan for gamete synthesis which is regulated by integration of homeostatic inputs such as nutrient status, and environmental cues. Signaling pathways integrate and transduce information from these cues to evoke a response. A decline in homeostasis and subsequent cues occurs over time, in the case of reproductive tissues leading to a progressive loss of fertility. The Janus Kinase and …