Cell and Developmental Biology Commons^™

An Essential Role For Endocytosis Of Rhodopsin Through Interaction Of Visual Arrestin With The Ap-2 Adaptor, Nicholas R. Orem, Luxi Xia, Patrick J. Dolph

Dartmouth Scholarship

Previously, we have identified a class of retinal degeneration mutants in Drosophila in which the normally transient interaction between arrestin2 (Arr2) and rhodopsin is stabilized and the complexes are rapidly internalized into the cell body by receptor-mediated endocytosis. The accumulation of protein complexes in the cytoplasm eventually results in photoreceptor cell death. We now show that the endocytic adapter protein AP-2 is essential for rhodopsin endocytosis through an Arr2-AP-2beta interaction, and mutations in Arr2 that disrupt its interaction with the beta subunit of AP-2 prevent endocytosis-induced retinal degeneration. We further demonstrate that if the interaction between Arr2 and AP-2 is …

Cloning And Overexpression Of Imp/Osta, An Essential Escherichia Coli Outer Membrane Protein With A Possible Role In Lipid Transport, Leslie Lekatz

Honors Capstones

Capstone submitted as a graduation requirement for the BSU Honors Program.

In Vitro Expression And Purification Of Class I Mhc Molecules, Loi Cheng

Honors Scholar Theses

The major histocompatibility complex (MHC) is a gene family responsible for many critical functions of the immune system in most vertebrates. The MHC consists of three classes differentiated by their structure and function, and MHC class I encodes antigen binding proteins as well as chaperone and accessory proteins such as tapasin. The purpose of this project is to reconstitute several human MHC class I molecules in their peptide-filled and peptide-deficient forms, and to purify these proteins for biochemical study. The expressed proteins include wild type and mutant variants of the fusion protein human leukocyte antigen HLA-B*0801-fos, and human beta-2-microglobulin (β2m). …

A Kinesin-Like Calmodulin-Binding Protein In Chlamydomonas: Evidence For A Role In Cell Division And Flagellar Functions, Erin E. Dymek, Daniel Goduti, Tal Kramer, Elizabeth F. Smith

Dartmouth Scholarship

Kinesin-like calmodulin-binding protein, KCBP, is a novel member of the C-kinesin superfamily first discovered in flowering plants. This minus-end-directed kinesin exhibits Ca(2+)-calmodulin-sensitive motor activity in vitro and has been implicated in trichome morphogenesis and cell division. A homologue of KCBP is also found in the unicellular, biflagellate green alga Chlamydomonas reinhardtii (CrKCBP). Unlike plant cells, Chlamydomonas cells do not form trichomes and do not assemble a phragmoplast before cell division. To test whether CrKCBP is involved in additional microtubule-based processes not observed in plants, we generated antibodies against the putative calmodulin-binding domain and used these antibodies in biochemical and localization …

Rapid Assimilation Of Yolk Enhances Growth And Development Of Lizard Embryos From A Cold Environment, Melissa Ann Blake

All-Inclusive List of Electronic Theses and Dissertations

Selection for rapid growth in cold environments results in a geographic pattern known as countergradient variation. The eastern fence lizard, Sceloporus undulatus, exhibits countergradient variation in growth rate across latitudinal clines. In a common-garden experiment, S. undulatus embryos from cold environments grew more efficiently than embryos warm environments, even when the energetic contents of eggs were equalized. To examine the physiological mechanisms of higher growth efficiency, I measured the energetics of embryos during the first 49 days of incubation. Specifically, I recorded body mass, residual yolk, total respiration, and developmental stage for embyos from two populations (Virginia and South Carolina). …

Catalase Activity Mediates The Inhibitory Actions Of 24,25 Dihydroxyvitamin D3, Sven L. Peery

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The steroid hormone 1,25-dihydroxyvitamin D₃ [1,25(OH)₂D₃] rapidly stimulates the uptake of phosphate in isolated chick intestinal cells, while the steroid 24,25-dihydroxyvitamin D₃ [24,25(OH)₂D₃] inhibits the rapid stimulation by 1,25(OH)₂D₃. Earlier work in this laboratory has indicated that a cellular binding protein for the 24,25(OH)₂D₃ is the enzyme catalase. Since binding resulted in decreased catalase activity and increased H₂O₂ production, studies were undertaken to determine if pro-oxidant conditions mimicked the inhibitory actions of 24,25(OH)₂D₃, and anti-oxidant conditions …

Exogenous Expression Of Human Na, K-Atpase Isoforms In Insect Cells, Christal Renee' Carpenter

McCabe Thesis Collection

The Na-K-ATPase or Na pump is a membrane bound enzyme that maintains a high concentration of K+ and low concentration of Na+ in most animal cells. Three subunits constitute the Na pump, named alpha (ex), beta (~). and gamma (y). The ex subunit is responsible for the catalytic and transport of the enzyme, the ~ subunit is important for bringing the ex to the plasma membrane of the cell, and y is a regulatory subunit of the Na pump. In addition, there are several molecular variants or isoforms of the ex and ~ subunits. At present four different ex (ex …

Development Of Self-Assembled Monolayer-Based Cell Culture Platform Towards Fabrication Of A Three-Dimensional Bioreactor, Rajendra Kandoor Aithal

Doctoral Dissertations

The extracellular matrix (ECM) plays an important role in regulating a number of cellular properties and functions like cell differentiation, cell synthesis and degradation, cell viability and proliferation, cell function, and cell aging. Surface modification of planar substrates with self-assembled monolayers (SAMs) is a promising technique to achieve stable ECMs.

In this work, substrates such as silicon (Si), gallium arsenide (GaAs) and indium tin oxide (ITO) substrates were modified with SAMS containing amino (-NH2), methyl (-CH3), thiol (-SH) and carboxylic (-COOH) end groups and characterized using contact angle measurements, surface infrared (IR) spectroscopy and atomic force microscopy (AFM). Different cell …

Talking To Themselves: Autoregulation And Quorum Sensing In Fungi, Deborah A. Hogan

Dartmouth Scholarship

Extracellular autoinducing compounds in the supernatants of microbial cultures were first recognized for their roles in the induction of genetic competence in gram-positive bacteria and in the regulation of light production in marine vibrios. In 1994, this form of population-level regulation in microbes was dubbed “quorum sensing” since it enabled bacterial cells to chemically measure the density of the surrounding population. Subsequently, many examples of cell density-dependent regulation by extracellular factors have been found in diverse microorganisms. The widespread incidence of diverse quorum-sensing systems strongly suggests that regulation in accordance with cell density is important for the success of microbes …

Olfactory Bulb Neurons Of Adult Zebrafish Morphology, Distribution, Cellular Interactions And Structural Stability Following Deafferentation, Cynthia L. Fuller

Dissertations

The zebrafish is becoming an increasingly popular model for studies involving olfactory function, yet there is still much to be learned about the anatomy and circuitry of different cell types in the olfactory bulb. This study focuses on identifying the morphology and distribution of output neurons and interneurons in the olfactory bulb of adult zebrafish, Danio rerio . Furthermore, this investigation examines the cellular interactions of the primary output neuron, the mitral cell, and addresses the issue of neuronal plasticity by considering the structural stability of this cell type following loss of afferent innervation.

Using retrograde tract tracing with various …

Comparative Genomic Analyses And Expression Of A Set Of Overlapping Open Reading Frames Of Frog Virus 3, Type Species Of Ranavirus (Family Iridoviridae), Wendy Guat Hoon Tan

Dissertations

Frog virus 3 (FV3) is the type species member of the genus Ranavirus (family Iridoviridae ). To better understand the molecular mechanisms involved in the replication of FV3, including transcription of its highly methylated DNA genome, the complete nucleotide sequence of the FV3 genome has been determined. The FV3 genome is 105, 903 base pairs long excluding the terminal redundancy. The G+C content of FV3 genome is 55% and it encodes 98 non-overlappingpotential open reading frames (ORFs) containing 50 to 1293 amino acids. Eighty-four ORFs have significant homology to known proteins of other iridoviruses, whereas 14 are unique FV3 ORFs. …

Nanosecond Pulsed Electric Field Effects On Cell Cycle And Apoptosis, Emily H. Hall

Theses and Dissertations in Biomedical Sciences

Apoptosis, programmed cell death, is a highly regulated and complex pathway essential for embryonic development, immune-system function and maintenance of tissue homeostasis where cells induce their own cell death. Cells undergoing apoptosis exhibit a distinctive phenotype characterized by maintenance of membrane integrity, cell shrinkage, phosphatidylserine (PS) externalization at the plasma membrane, caspase protease activation, DNA fragmentation, release of cytochrome c from the mitochondrion, and membrane blebbing. An important regulatory protein in the apoptotic pathway is p53. The p53 protein functions to modulate the cell cycle by arresting cells in the G1 and G 2 phases to repair DNA damage, and/or …

Modulation Of Tgfβ-Induced Pai -1 Expression By Changes In Actin Polymerization In Human Mesangial Cells, Keyur Patel

Theses and Dissertations in Biomedical Sciences

Chronic renal diseases show increased deposition of extracellular matrix (ECM) in the glomerulus (glomerulosclerosis). Glomerulosclerosis is associated with activation of normally quiescent glomerular mesangial cells into myofibroblast-like cells. The overall objective of this study is to delineate cellular mechanism/s of myofibroblast-differentiation in disease states. In cultured mesangial cells certain characteristics of myofibroblast differentiation (α-smooth muscle actin (α-SMA) and hypertrophy) are associated with an increase in polymeric actin microfilaments (stress fibers). It is likely that other genes are also regulated in an actin cytoskeleton-dependent manner during myofibroblast differentiation. In these studies, we therefore examined the hypothesis that changes in the actin …

The Study Of Nitric Oxide Synthase Expression, Function, And Regulation In The Renal Vasculature During Postnatal Renal Development, Brian Blake Ratliff

Theses and Dissertations in Biomedical Sciences

The newborn kidney is vulnerable to vasomotor acute renal failure (ARF) from adverse perinatal events or complications of prematurity. Nitric oxide (NO) vasodilation is vitally protective in this type of ARF, but its relationship with other vasoactive factors, such as angiotensin II (AII) has not been examined. In the immature kidney, nitric oxide synthase (NOS) isoforms, specifically eNOS and nNOS, are developmentally regulated, but their specific role and regulation are unknown.

The enhanced vasodilatory role of NO in the immature kidney was hypothesized to be attributed to regulatory, expressional, and functional differences in eNOS and nNOS isoforms from the adult. …

The Role Of Fgfr4 In Trigeminal Placode Cell Development, Stephanie Beth Reynolds

Theses and Dissertations

In vertebrate embryos, the ophthalmic trigeminal (opV) placode contributes sensory neurons to the trigeminal ganglion during development of the peripheral nervous system. FGFR4 is expressed transiently in the trigeminal placode as cells undergo an epithelial-mesenchymal transition and begin to migrate toward the condensing ganglion. Because of the restricted spatiotemporal expression of FGFR4 in the opV placode, it was hypothesized that FGFR4 is necessary for the process of epithelial-mesenchymal transition in the opV placode. Using electroporation, an FGFR4 inhibitory gene construct was introduced into 6—10 somite stage chick embryos. This secreted inhibitory form of the FGFR4 gene blocked endogenous FGFR4 signaling, …

The Role Of Pax3 In Neuronal Differentiation Of The Ophthalmic (Opv) Trigeminal Placode And Neural Tube During Chicken Embryonic Development, James R. Bradshaw

Theses and Dissertations

Pax3 has been used as a valuable marker in research aimed at understanding tissue interactions involved in trigeminal ophthalmic (opV) placode development. While Pax3 expression coincides with opV neuron specification, the function of Pax3 in these cells has not previously been investigated. Splotch mutant mice (which lack Pax3) have a reduced trigeminal ganglion; however it is not clear whether this reduction is due to neural crest or placode cells. We have used electroporation in the chick model system to block or ectopically express Pax3 at key times in opV placode development. Using several markers of placode cell differentiation, we have …

Phylogenetic Analyses Of Mtdna Sequences Reveal Three Cryptic Lineages In The Widespread Neotropical Frog Leptodactylus Fuscus (Schneider, 1799) (Anura, Leptodactylidae), Arley Camargo, Rafael O. De Sá, W. Ronald Heyer

Biology Faculty Publications

Leptodactylus fuscus is a neotropical frog ranging from Panamá to Argentina, to the east of the Andes mountains, and also inhabiting Margarita, Trinidad, and the Tobago islands. We performed phylogenetic analyses of 12S rRNA, 16S rRNA, tRNA-Leu, and ND1 mitochondrial (mt) DNA sequences from specimens collected across the geographic distribution of L. fuscus to examine two alternative hypotheses: (i) L. fuscus is a single, widely distributed species, or (ii) L. fuscus is a species complex. We tested statistically for geographic association and partitioning of genetic variation among mtDNA clades. The mtDNA data supported the hypothesis of several cryptic species within …

Transcriptome Signature Of Virulent And Attenuated Pseudorabies Virus-Infected Rodent Brain, Christina Paulus, Patricia J. Sollars, Gary E. Pickard, Lynn W. Enquist

School of Veterinary and Biomedical Sciences: Faculty Publications

Mammalian alphaherpesviruses normally establish latent infections in ganglia of the peripheral nervous system in their natural hosts. Occasionally, however, these viruses spread to the central nervous system (CNS), where they cause damaging, often fatal, infections. Attenuated alphaherpesvirus derivatives have been used extensively as neuronal circuit tracers in a variety of animal models. Their circuit-specific spread provides a unique paradigm to study the local and global CNS response to infection. Thus, we systematically analyzed the host gene expression profile after acute pseudorabies virus (PRV) infection of the CNS using Affymetrix GeneChip technology. Rats were injected intraocularly with one of three selected …

Chmp1 Is Implicated In The Development Of Pancreatic Tumor Via The Retinoic Acid Signaling Pathway, Juliana Adedayo Akinsete

Theses, Dissertations and Capstones

In the present study, we investigated the involvement of Chmp1 (Chromatin ModifyingProtein 1/Charged Multivesicular body Protein 1) in the development of mousepancreatic acinar tumor cell line. CRL 2151 cell line was transfected with Chmp1/CS2vector to compare growth, morphology and expression of Chmp1, p53 and pp53 (ser37) with control-transfected cells. CRL 2151 cells were treated with all-trans retinoicacid (ATRA) to compare growth, morphology and expression of Chmp1 and p53 withcontrol-treated cells. Strabismus was used as control. Results showed inhibition ofgrowth but no morphological change in transfected cells. Western blot analysis showedthat Chmp1 transfection upregulated the expression of p53, pp53 and Stbm …

Characterization Of The Dna-Binding Properties Of Silent Information Regulator 3 Protein, Cotteka Nichisha Johnson

Theses, Dissertations and Capstones

The eukaryotic genome is organized into distinct domains with discrete regulatory potential, influenced by the variation in local chromatin structure. An example of chromatin-mediated consequences on gene expression is mating type determination of yeast Saccharomyces cerevisiae, which depends on silencing of specific gene cassettes. Silencing in yeast involves key proteins, amongst which the Silent Information Regulator (Sir) proteins are essential. Sir1p, Sir2p, and Sir4p are recruited to nucleate silencing events, while Sir3p serves as the pivotal factor in spreading the silent state. This investigation characterizes the DNA binding properties of Sir3p using DNA fragments with varying degrees of inherent flexibility, …

Linking Ligand-Induced Alterations In Androgen Receptor Structure To Differential Gene Expression: A First Step In The Rational Design Of Selective Androgen Receptor Modulators, Dmitri Kazmin, Tatiana Prytkova, C. Edgar Cook, Russell Wolfinger, Tzu-Ming Chu, David Beratan, J. D. Norris, Ching-Yi Chang, Donald P. Mcdonnell

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We have previously identified a family of novel androgen receptor (AR) ligands that, upon binding, enable AR to adopt structures distinct from that observed in the presence of canonical agonists. In this report, we describe the use of these compounds to establish a relationship between AR structure and biological activity with a view to defining a rational approach with which to identify useful selective AR modulators. To this end, we used combinatorial peptide phage display coupled with molecular dynamic structure analysis to identify the surfaces on AR that are exposed specifically in the presence of selected AR ligands. Subsequently, we …

Overexpression And Purification Of The Oat (Avena Fatua) Protein Afn1 And Construction Of A Pmal/Afn1 Expression Plasmid, Tenzin D. Tsewang

Undergraduate Research Symposium (UGRS)

Abscisic acid (ABA) is an important phytohormone with regulatory roles in many physiological processes. ABA expression is induced by environmental stresses such as drought and it is known to be an inhibitor of seed germination. A wild oat (Avena fatua) called AFN1 has been hypothesized to initiate the early stages of germination as its mRNA accumulates in nondormant seed embryos during imbibition. The polypeptide sequence of AFN1 suggests that it is an ABA glucosyl transferase. Glucosylation by AFN1 and thereby inactivation of ABA could lead to seed germination. In order to understand the role of AFN1 in germination, an ample …

Dynamin As A Mover And Pincher During Cell Migration And Invasion, Anne E. Kruchten, Mark A. Mcniven

Faculty Publications

The large GTPase dynamin, long known for its role in endocytosis, has most recently been implicated as a facilitator of cell migration and invasion. Recent observations link dynamin to the cycle of membrane expansion and retraction essential for cell motility. Its role in actin polymerization, membrane deformation and vesiculation, and focal adhesion dynamics are all important for this process, and the new findings provide exciting directions for studies of this ubiquitous and diverse protein family.

Endothelial Cell Cortactin Phosphorylation By Src Contributes To Polymorphonuclear Leukocyte Transmigration In Vitro, L. Yang, Jennifer R. Kowalski, X. Zhan, S. M. Thomas, F. W. Luscinskas

Scholarship and Professional Work - LAS

The underlying mechanisms that regulate leukocyte transendothelial migration through the vascular endothelium remain unclear. Cortactin is a substrate of Src tyrosine kinases and a regulator of cytoskeletal dynamics. Previous studies demonstrated a role for Src phosphorylation of cortactin in clustering of E-selectin and intercellular cell adhesion molecule-1 around adherent leukocytes. In the current study, we used an in vitro flow model to investigate the role of Src-induced cortactin phosphorylation in endothelium during polymorphonuclear leukocyte (PMN) transmigration through human umbilical vein endothelium (HUVEC) monolayers preactivated with tumor necrosis factor-{alpha}. Inhibition of Src in HUVEC using Src kinase inhibitors PP2 and SU6656 …

Neuronal Pentraxins Mediate Synaptic Refinement In The Developing Visual System, Lisa Bjartmar, Andrew Huberman, Erik Ullian, Rene Renterıa, Xiaoqin Liu, Weifeng Xu, Jennifer Prezioso, Michael Susman, David Stellwagen, Caleb Stokes, Richard Cho, Paul Worley, Robert Malenka, Sherry Ball, Neal Peachey, David Copenhagen, Barbara Chapman, Masaru Nakamoto, Ben Barres, Mark Perin

Biology Faculty Publications

 Neuronal pentraxins (NPs) define a family of proteins that are homologous to C-reactive and acute-phase proteins in the immune system and have been hypothesized to be involved in activity-dependent synaptic plasticity. To investigate the role of NPs in vivo , we generated mice that lack one, two, or all three NPs. NP1/2 knock-out mice exhibited defects in the segregation of eye-specific retinal ganglion cell (RGC) projections to the dorsal lateral geniculate nucleus, a process that involves activity-dependent synapse formation and elimination. Retinas from mice lacking NP1 and NP2 had cholinergically driven waves of activity that occurred at a frequency similar …

Characterization Of The Wheat Grain Pkaba1-Interacting Protein Tawd40, Natalie Wayne

Undergraduate Research Symposium (UGRS)

Abscisic acid (ABA)-mediated gene expression is a critical component of plant responses to this important hormone, which affects plant growth, development, and responses to environmental stresses. Plant responses to ABA are mediated by a number of factors including PKABA1, an ABA induced protein kinase involved in ABA-suppressed gene expression in cereal grains, and TaWD40, which has previously been shown to physically interact with PKABA1. A full-length 1.9 kb TaWD40 cDNA, CK210682, was sequenced as part of this project. Based on the deduced protein sequence, it is thought that TaWD40 may belong to the family of E3 ubiquitin ligases, possibly targeting …

A Group M Consensus Envelope Glycoprotein Induces Antibodies That Neutralize Subsets Of Subtype B And C Hiv-1 Primary Viruses, Hua-Xin Lin, Laura L. Sutherland, Shi-Mao Xia, Mary E. Brock, Richard M. Scearce, Stacie Vanleeuwen, S. Munir Alam, Mildred Mcadams, Eric A. Weaver, Zenaido T. Camacho, Ben-Jiang Ma, Yingying Li, Julie M. Decker, Gary J. Nabel, David C. Montefiori, Beatrice H. Hahn, Bette T. Korber, Feng Gao, Barton F. Haynes

Nebraska Center for Virology: Faculty Publications

HIV-1 subtype C is the most common HIV-1 group M subtype in Africa and many parts of Asia. However, to date HIV-1 vaccine candidate immunogens have not induced potent and broadly neutralizing antibodies against subtype C primary isolates. We have used a centralized gene strategy to address HIV-1 diversity, and generated a group M consensus envelope gene with shortened consensus variable loops (CON-S) for comparative studies with wildtype (WT) Env immunogens. Our results indicate that the consensus HIV-1 group M CON-S Env elicited cross-subtype neutralizing antibodies of similar or greater breadth and titer than the WT Envs tested, indicating the …

Methods For The Study Of Signaling Molecules In Membrane Lipid Rafts And Caveolae, Rennolds S. Ostrom, Paul A. Insel

Pharmacy Faculty Articles and Research

Lipid rafts and caveolae are cholesterol- and sphingolipid-rich microdomains of the plasma membrane that concentrate components of certain signal transduction pathways. Interest in and exploration of these microdomains has grown in recent years, especially after the discovery of the biochemical marker of caveolae, caveolin, and the recognition that caveolin interacts with many different signaling molecules via its scaffolding domain. There are three major types of caveolins (1, 2, and 3), with some selectivity in their expression in different tissues. Results assessing lipid raft/caveolae co-localization of molecules in signal transduction pathways have provided support for the idea that signaling components are …

Organometallic Ruthenium Complexes Of Novel Thiosemicarbazones, Floyd A. Beckford, Amon T. Holt

Journal of the Arkansas Academy of Science

We present the preliminary results of a study of two novel thiosemicarbazones (TSCs) and theirruthenium complexes. The TSCs were prepared by refluxing thiosemicarbazide with 9-anthraldehyde or benzanthrone in ethanol for 3 hours. The metal complex of each ligand (complex I =[(r|6 -C6H6 )Ru(9-ant-TSC )(C1)]C1 and complex II= [(r|6 -C6H6 )Ru(benz-TSC)(Cl)]Cl) was prepared by refluxing the appropriate TSC with [(r|6 -C6H6 )RuCl 2 ] r The compounds were characterized using infrared, ultraviolet-visible, and NMRspectroscopy. Two different methods, the disk diffusion test and luminometry, were used to test the compounds against a variety of different bacterial strains for antibacterial activity. The most …

Never Let Me Clone? Countering An Ethical Argument Against The Reproductive Cloning Of Humans, Yvette Pearson

Philosophy Faculty Publications

In the March 2006 issue of EMBO reports, Christof Tannert, a bioethicist at the Max Delbrück Research Centre in Berlin, Germany, presented a moral argument against human reproductive cloning on the basis of Immanuel Kant’s categorical imperative (Tannert, 2006). In this article, I address some problems with Tannert’s views and show that our concerns about this prospective procedure should prompt us to scrutinize carefully the conventional procreative practices and attitudes. Indeed, if we set aside objections that are grounded in genetic determinism, many of the offensive features of human cloning are identical to problems with procreation by more conventional means, …