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Articles 1 - 13 of 13
Full-Text Articles in Cell Biology
Regulation Of The Wnt/Wingless Receptor Lrp6/Arrow By The Deubiquitylating Complex Usp46, Zachary T. Spencer
Regulation Of The Wnt/Wingless Receptor Lrp6/Arrow By The Deubiquitylating Complex Usp46, Zachary T. Spencer
Dartmouth College Ph.D Dissertations
The evolutionarily conserved Wnt/Wingless signal transduction pathway is critical for the proper development of all animals and implicated in numerous diseases in adulthood. Upon binding of the Wnt/Wingless ligand, a cascade of events culminates in inactivation of the destruction complex, a negative regulator of the pathway, and the subsequent formation of singalosomes which mediate pathway activation. A critical component of signalosome formation is the Wnt/Wingless receptor LRP6/Arrow. Upon canonical pathway activation, LRP6/Arrow undergoes activation via phosphorylation by several kinases and complexes with another Wnt/Wingless receptor Frizzled, along with several cytoplasmic components. While many studies have investigated the regulatory mechanisms of …
Regulation Of Tissue Mechanics And Adherens Junctions By Small Gtpase Rhoa During Drosophila Embryogenesis, Hanqing Guo
Regulation Of Tissue Mechanics And Adherens Junctions By Small Gtpase Rhoa During Drosophila Embryogenesis, Hanqing Guo
Dartmouth College Ph.D Dissertations
Actomyosin contractility plays an important role at both the cell and tissue level during developments. In this study, we developed an optogenetic tool that can acutely inhibit actomyosin contractility by targeting its main activator Rho1. This optogenetic tool can achieve myosin inhibition within one minute and thus enable further dissection of actomyosin function in development. In my first two projects, I used Drosophila mesoderm invagination (also known as ventral furrow formation) as a model to study epithelial folding, a fundamental mechanism for constructing complex 3D tissues. Apical constriction mediated by actomyosin contractility is a common mechanism for epithelial folding. However, …
Launching The Next Generation : Transcriptional Regulation During Oogenesis, Alicia K. Mccarthy
Launching The Next Generation : Transcriptional Regulation During Oogenesis, Alicia K. Mccarthy
Legacy Theses & Dissertations (2009 - 2024)
Germ cells give rise to gametes and link generations by passing genetic information from parent to offspring. Gametes arise from, in many sexually reproducing organisms, germline stem cells (GSCs) which are set aside early during development. GSCs have an amazing capacity to undergo self-renewal to give rise to a pool of undifferentiated cells, while also differentiating to generate specialized germ cells such as haploid gametes. Upon female GSC differentiation, mitotically dividing germ cells can initiate meiosis, and mature within a follicle. During maturation, the specified oocyte is provided with a trust fund of RNAs and proteins for the next generation …
Delineation Of Events In Centripetal Migration During Drosophila Oogenesis, Travis Tait Parsons
Delineation Of Events In Centripetal Migration During Drosophila Oogenesis, Travis Tait Parsons
UNLV Theses, Dissertations, Professional Papers, and Capstones
All multicellular organisms initially start out as a single cell. This cell must use the genetic information encoded in its DNA to multiply in number and build itself into a complex multicellular organism. How this process occurs is the focus of developmental biology, a field that seeks to understand how a combination of genetic information and environmental conditions shape a cell from its beginnings as a zygote all the way to maturity. A fundamental part of this process is the ability of cells to work together in order to build complex tissues and organs. Cells achieve this coordination by using …
Mechanisms Of Oriented Cell Division And Their Roles In Tissue Development, Evan Blake Dewey
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 Drosophila Neuroblasts: A Model System For Human Ribosomopathies, Sonu Shrestha Baral
The Drosophila Neuroblasts: A Model System For Human Ribosomopathies, Sonu Shrestha Baral
LSU Doctoral Dissertations
This dissertation describes the use of Drosophila neuroblasts (NBs) to model human ribosomopathies; the overall goal is to understand why specific stem cell and progenitor cell populations are the primary targets in nucleolar stress as seen in the ribosomopathies. Chapter 1 provides an overview of relevant literature. Chapter 2 describes nucleolar stress in Drosophila neuroblasts as a model for human ribosomopathies. For this, we induce nucleolar stress by using the UAS-GAL4 system to express RNAi that depletes Nopp140 transcripts, and we also employ homozygous, CRISPR-Cas9-generated Nopp140 gene disruptions with a systemic null phenotype (Nopp140-/-). Embryonic lethality was observed …
Studies Of Norspermidine Uptake In Drosophila Suggest The Existence Of Multiple Polyamine Transport Pathways, Michael Dieffenbach
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 …
Regulated Transcriptional Silencing Promotes Germline Stem Cell Differentiation In Drosophila Melanogaster, Pooja Flora
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
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.
Characterization Of Vesicular Monoamine Transporter 2 And Its Role In Parkinson's Disease Pathogenesis Using Drosophila, Antonio Joel Tito Jr., Sheng Zhang
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 …
Axonal Transport And Life Cycle Of Mitochondria In Parkinson's Disease Model, Hyun Sung
Axonal Transport And Life Cycle Of Mitochondria In Parkinson's Disease Model, Hyun Sung
Open Access Dissertations
In neurons, normal distribution and selective removal of mitochondria are essential for preserving compartmentalized cellular function. Parkin, an E3 ubiquitin ligase associated with familial Parkinson’s disease, has been implicated in mitochondrial dynamics and removal. However, it is not clear how Parkin plays a role in mitochondrial turnover in vivo, and whether the mature neurons possess a compartmentalized Parkin-dependent mitochondrial life cycle. Using the live Drosophila nervous system, here, I investigate the involvement of Parkin in mitochondrial dynamics; organelle distribution, morphology and removal. Parkin deficient animals displayed less number of axonal mitochondria without disturbing organelle motility behaviors, morphology and metabolic state. …
A Microrna Imparts Robustness Against Environmental Fluctuation During Development, Xin Li, Justin J. Cassidy, Catherine A. Reinke, Stephen Fischboeck, Richard W. Carthew
A Microrna Imparts Robustness Against Environmental Fluctuation During Development, Xin Li, Justin J. Cassidy, Catherine A. Reinke, Stephen Fischboeck, Richard W. Carthew
Faculty Publications
The microRNA miR-7 is perfectly conserved from annelids to humans, and yet some of the genes that it regulates in Drosophila are not regulated in mammals. We have explored the role of lineage restricted targets, using Drosophila , in order to better understand the evolutionary significance of microRNA-target relationships. From studies of two well characterized developmental regulatory networks, we find that miR-7 functions in several interlocking feedback and feedforward loops, and propose that its role in these networks is to buffer them against perturbation. To directly demonstrate this function for miR-7, we subjected the networks to temperature fluctuation and found …
Effects Of Chemical Aneuploidogens On Taxol Purified Drosophila And Mouse Brain Microtubules Polymerization And Depolymerization In Vitro, Anil Sehgal
Biological Sciences Theses & Dissertations
The effects of aneuploidogens (aneuploidy causing agents) on taxol-purified microtubules from Drosophila and mouse brain in vitro were studied by using a spectrophotometric assay and electron microscopy. Colchicine, acetonitrile, propionitrile, acrylonitrile, dimethyl sulfoxide (DMSO), griseofulvin and cadmium chloride inhibited microtubule polymerization whereas methoxyethyl acetate (MEA) and methyl mercuric chloride (MMC) did not. All aneuploidogens tested (at 50mM) resulted in reduced rate of elongation of mouse brain microtubules. MMC, cadmium chloride and DMSO resulted in increased rates of Drosophila microtubule elongation whereas the rest of the drugs resulted in decreases. The in vitro results from Drosophila correlate well with the previously …