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 …

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). …

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 …

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. …

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 …

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 …

Eye Development At The Houston "Fly Meeting", Amit Singh

Biology Faculty Publications

Meeting report: The 47th Annual Drosophila Research Conference or "Fly Meeting" took place at Houston, Texas, USA from March 29th- April 2nd, 2006, under the aegis of the Genetics Society of America. The Fly Meeting provides an excellent opportunity for fly researchers to present their work and to get a snapshot of recent developments and upcoming trends in their research field. The fruit fly, Drosophila melanogaster, is a very versatile model to study growth, patterning, neural development, evolution, systemetics and various other facets of biomedical science. The topics presented in the meeting covered a very broad spectrum of fly research. …

Development Of Proliferation Assays To Explore The Role Of Calcium Activated Potassium Channels In Cell Proliferation, Sean Foster

Honors Theses

Due to the large variety of K^† channel families implicated in cancer cell proliferation, it is desirable to develop techniques capable of quickly and reliably screening a variety of potential channels for a role in proliferation. While there are many established cell counting procedures, the time-consuming nature of such protocols limits their usefulness in broadly identifying particular channels in uncharacterized cell lines. For this reason, a primary goal of the present research was the development of techniques capable of implicating particular ion channels in proliferation with both qualitative and quantitative data. Once this goal was accomplished, the project sought …

The Amphibian Tree Of Life, Darrel R. Frost, Taran Grant, Julián Faivovich, Raoul H. Bain, Alexander Haas, Célio F.B. Haddad, Rafael O. De Sá

Biology Faculty Publications

The evidentiary basis of the currently accepted classification of living amphibians is discussed and shown not to warrant the degree of authority conferred on it by use and tradition. A new taxonomy of living amphibians is proposed to correct the deficiencies of the old one. This new taxonomy is based on the largest phylogenetic analysis of living Amphibia so far accomplished. We combined the comparative anatomical character evidence of Haas (2003) with DNA sequences from the mitochondrial transcription unit H1 (12S and 16S ribosomal RNA and tRNAValine genes, ø 2,400 bp of mitochondrial sequences) and the nuclear genes histone H3, …

Empirical Analysis Of The Str Profiles Resulting From Conceptual Mixtures, David R. Paoletti, Travis E. Doom, Carissa M. Krane, Michael L. Raymer, Dan E. Krane

Biology Faculty Publications

Samples containing DNA from two or more individuals can be difficult to interpret. Even ascertaining the number of contributors can be challenging and associated uncertainties can have dramatic effects on the interpretation of testing results. Using an FBI genotypes dataset, containing complete genotype information from the 13 Combined DNA Index System (CODIS) loci for 959 individuals, all possible mixtures of three individuals were exhaustively and empirically computed. Allele sharing between pairs of individuals in the original dataset, a randomized dataset and datasets of generated cousins and siblings was evaluated as were the number of loci that were necessary to reliably …

Atypical Pkciota Contributes To Poor Prognosis Through Loss Of Apical-Basal Polarity And Cyclin E Overexpression In Ovarian Cancer, Astrid M. Eder, Xiaomei Sui, Daniel G. Rosen, Laura K. Nolden, Kwai Wa Cheng, John P. Lahad, Madhuri Kango-Singh, Karen H. Lu, Carla L. Warneke, Edward N. Atkinson, Isabelle Bedrosian, Khandan Keyomarsi, Wen-Lin Kuo, Joe W. Gray, Jerry C. P. Yin, Jinsong Liu, Georg Halder, Gordon B. Mills

Biology Faculty Publications

We show that atypical PKCι, which plays a critical role in the establishment and maintenance of epithelial cell polarity, is genomically amplified and overexpressed in serous epithelial ovarian cancers. Furthermore, PKCι protein is markedly increased or mislocalized in all serous ovarian cancers. An increased PKCι DNA copy number is associated with decreased progression-free survival in serous epithelial ovarian cancers. In a Drosophila in vivo epithelial tissue model, overexpression of persistently active atypical PKC results in defects in apical-basal polarity, increased Cyclin E protein expression, and increased proliferation. Similar to the Drosophila model, increased PKCι proteins levels are associated with …

Group 13 Hox Proteins Interact With The Mh2 Domain Of R-Smads And Modulate Smad Transcriptional Activation Functions Independent Of Hox Dna Binding Capability, Thomas M. Williams, Melissa E. Williams, Joanne H. Heaton, Thomas D. Gelehrter, Jeffrey W. Innis

Biology Faculty Publications

Interactions with co-factors provide a means by which HOX proteins exert specificity. To identify candidate protein interactors of HOXA13, we created and screened an E11.5–E12.5, distal limb bud yeast two-hybrid prey library. Among the interactors, we isolated the BMP-signaling effector Smad5, which interacted with the paralogous HOXD13 but not with HOXA11 or HOXA9, revealing unique interaction capabilities of the AbdB-like HOX proteins. Using deletion mutants, we determined that the MH2 domain of Smad5 is necessary for HOXA13 interaction.

This is the first report demonstrating an interaction between HOX proteins and the MH2 domain of Smad proteins. HOXA13 and HOXD13 …

Calmodulin And Pf6 Are Components Of A Complex That Localizes To The C1 Microtubule Of The Flagellar Central Apparatus, Matthew J. Wargo, Erin E. Dymek, Elizabeth F. Smith

Dartmouth Scholarship

Studies of flagellar motility in Chlamydomonas mutants lacking specific central apparatus components have supported the hypothesis that the inherent asymmetry of this structure provides important spatial cues for asymmetric regulation of dynein activity. These studies have also suggested that specific projections associated with the C1 and C2 central tubules make unique contributions to modulating motility; yet, we still do not know the identities of most polypeptides associated with the central tubules. To identify components of the C1a projection, we took an immunoprecipitation approach using antibodies generated against PF6. The pf6 mutant lacks the C1a projection and possesses flagella that only …

Methods For Non-Invasive Body Temperature Measurement And Partitioning Heat Loss To Air And Water From Swimming Mallard Ducklings (Anas Platyrhynchos), Matthew J. Van Sant

All-Inclusive List of Electronic Theses and Dissertations

Water birds whose young begin swimming while downy are interesting because hypothermia and mortality are associated with wetting. Wetting is known to increase heat loss, but little is known about the amount of heat lost to air vs. water during swimming. Accurate measurements of body temperature are required in studies investigating heat loss. I used 2-d to 3-d-old mallard ducklings (Anas platyrhynchos) to test whether remote thermographic measurement of scalp temperature could be used to estimate core temperature from a distance. For wind speeds of up to 2.5 mis, I found cloaca} temperature could be estimated to within 1 °C …

Phosphotyrosine Phosphatases Of The Att-20 Murine Corticotroph Cell Line, Kari A. Belin

Seton Hall University Dissertations and Theses (ETDs)

Somatostatin (somatotropin release inhibitory factor; SRIF) is a peptide-signaling molecule that activates a family of heterotrimeric guanine nucleotide binding protein (G­ protein) coupled receptors (sst.-sst-). SRIF receptors control essential intracellular signaling events and, by reducing cyclic nucleotide levels, ion concentrations and protein phosphorylation, ultimately controlling cell proliferation and secretion. In the current study, we investigated the intracellular phosphatase activity present in the AtT-20 cell, as well as whether these enzymes were under direct SRIF receptor control. AtT-20 cells retain many of the properties of anterior pituitary corticotrophs, yet are an established cell line that expresses at least two SRIF receptor …

The Effect Of Rooibos Tea (Aspalathus Linearis) On The Survival And Transformation Of C3h-Bt1 Mouse Fibroblasts, Krista M. Beach, Paul J. Smith

Honors Capstones

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

The Glucose And Insulin Responsiveness Of The Rat Glucose-6-Phosphate Dehydrogenase Promoter, Daryl Arkwright-Keeler

Dissertations

The regulation of expression of some enzymes involved in glucose homeostasis and fat metabolism requires both insulin and glucose to elicit an effect, while the regulation of others requires only one. Glucose-6-phosphate dehydrogenase (G6PDH), an important enzyme involved in glucose homeostasis, has been shown to be transcriptionally regulated by carbohydrate feeding in rat liver, a diet regime that increases the levels of both glucose and insulin. Our lab had previously shown that insulin induces expression of G6PDH, thus we wanted to determine if glucose also induced G6PDH expression and if so, are the glucose and insulin responses mediated through identical …

Changes In Glial Cell Line Derived Neurotrophic Factor And Nerve Growth Factor Expression With Development, Age, Exercise And Hypertension, Bertha C. Rebimbas-Cohen

Dissertations

Neurotrophic factors are important for neuronal growth, survival, and maintenance of cell phenotype. Glial cell line-derived neurotrophic factor (GDNF) affects sensory, autonomic and somatic motor neurons and nerve growth factor (NGF) affects sensory and sympathetic neurons. NGF and GDNF are produced by cardiac muscle and have potent effects on sensory and autonomic neuronal innervation of blood vessels. Neural innervation plays a key role in blood vessel function. Since neural innervation of blood vessels may be regulated by growth factors, we wanted to determine what changes would occur to NGF and GDNF levels with maturity, exercise and hypertension.

Changes in GDNF …

Analysis Of Genotypic And Phenotypic Differences In Desmognathus Quadramaculatus Across The Southern Appalachians, Deborah Susan Merritt

Theses, Dissertations and Capstones

Populations of Desmognathus quadramaculatus were compared for genotypic and phenotypic differences across 5 states in the Southern Appalachians. Series consisting of 10 salamanders each were collected from West Virginia, Virginia, Tennessee, North Carolina and Georgia. Salamanders were assessed for genotypic differences by using allozyme (proteins with polymorphic loci) electrophoresis staining for 13 loci of the muscle, liver and stomach tissue. Nei’s genetic distance was used to score genetic variation between populations. Phenotypic differences were assessed by comparing 10 external morphological measurements between populations. Mahalanobis’ distance was used to score morphological differences between populations. Both genetic and morphological differences were correlated …

Cortactin Regulates Cell Migration Via Activation Of N-Wasp, Jennifer Kowalski, C. Egile, S. Gil, S. B. Snapper, R. Li, S. M. Thomas

Scholarship and Professional Work - LAS

Cortactin is an actin-associated scaffolding protein that regulates cell migration. Amplification of the human gene, EMS1, has been detected in breast, head and neck tumors, where it correlates with increased invasiveness. Cortactin can regulate actin dynamics directly via its N-terminal half, which can bind and activate the Arp2/3 complex. The C-terminal portion of cortactin, however, is thought to have limited function in its regulation of the actin polymerization machinery. In this report, we identify a role for the cortactin C-terminus in regulating cell migration and, more specifically, actin dynamics. Overexpression of either full-length cortactin or cortactin C-terminus is sufficient to …

Cytokine Expression By T. Helper Cells Responding To Stress, Dina Zanetti

Master's Theses

Stress causes alterations to the immune system. These alterations have lead to increased susceptibility to antigens. The present study explores shifts in T helper (TH) cell balance (TH1 and TH2), through their cytokine expression. This study was performed in three phases, and focused mainly on animals subjected to a 10 day a chronic unpredictable stress paradigm. Phase one used ELISAs to confirm the cytokine profile produced from TH 1 and TH2 murine cell-lines. Phase two used SDS PAGE and Western Immunoblotting to show that splenocytes from Long Evan's Hooded rats subjected to the stress paradigm, had decreased in intercellular in …

Characterization Of Migrating Cells From Ventricular Zone (Vz) To Distant Limbic Structures After Multiple Neonatal Seizures, Melissa Corcia

Seton Hall University Dissertations and Theses (ETDs)

.

On The Enigmatic Distribution Of The Honduran Endemic Leptodactylus Silvanimbus (Amphibia: Anura: Lep Todactylidae), W. Ronald Heyer, Rafael O. De Sá, Sarah Muller

Biology Faculty Publications

Most species of the frog genus Leptodactylus occur in South America, and all authors who have treated the zoogeography of the genus have concluded that it originated somewhere in South America (e.g., Savage 1982). Savage (1982,518) summarized the historical herpetofaunal units of the Neotropics as follows: "All evidence points to an ancient contiguity and essential similarity of a generalized tropical herpetofauna that ranged over tropical North, Middle, and most of South America in Cretaceous-Paleocene times. Descendents of this fauna are represented today by the South and Middle American tracks (Elements). To the north of this fauna ranged a subtropical-temperate Laurasian …

Phylogenetic Relationships Of African Microhylid Frogs Inferred From Dna Sequences Of Mitochondrial 12s And 16s Rrna Genes, Simon P. Loader, David J. Gower, Kim M. Howell, Nike Doggart, Mark-Oliver Rödel, Barry T. Clarke, Rafael O. De Sá, Bernard L. Cohen, Mark Wilkinson

Biology Faculty Publications

The phylogenetic relationships of microhylid frogs are poorly understood. The first molecular phylogeny for continental African microhylids is presented, including representatives of all subfamilies, six of the eight genera, and the enigmatic hemisotid Hemisus. Mitochondrial 12S and 16S rRNA sequence data were analysed using parsimony, likelihood and Bayesian methods. Analyses of the data are consistent with the monophyly of all sampled subfamilies and genera. Hemisus does not nest within either brevicipitines or non-brevicipitines. It is possibly the sister group to brevicipitines, in which case brevicipitines might not be microhylids. Phrynomantis and Hoplophryne potentially group with non-African, non-brevicipitine microhylids, in …

Kinetics And Relative Importance Of Phosphorolytic And Hydrolytic Cleavage Of Cellodextrins And Cellobiose In Cell Extracts Of Clostridium Thermocellum, Yie.-Heng P. Zhang, Lee R. Lynd

Dartmouth Scholarship

Rates of phosphorolytic cleavage of 􏰁-glucan substrates were determined for cell extracts from Clostridium thermocellum ATCC 27405 and were compared to rates of hydrolytic cleavage. Reactions with cellopentaose and cellobiose were evaluated for both cellulose (Avicel)- and cellobiose-grown cultures, with more limited data also obtained for cellotetraose. To measure the reaction rate in the chain-shortening direction at elevated temper- atures, an assay protocol was developed featuring discrete sampling at 60°C followed by subsequent analysis of reaction products (glucose and glucose-1-phosphate) at 35°C. Calculated rates of phosphorolytic cleavage for cell extract from Avicel-grown cells exceeded rates of hydrolytic cleavage by >20-fold …

Use Of Cre Recombinase And Sb Transposase To Engineer Transgenic Zebrafish, Jie Dong

All-Inclusive List of Electronic Theses and Dissertations

Current transgenesis has become easier for certain species due to the recent development of exogenous non site-specific recombination systems such as Sleeping Beauty (SB) transposon, and site-specific recombination systems such as Cre-loxP. Such recombination systems overcame two major problems caused by conventional transgenesis, position effect and copy number effect. SB is a reconstructed fish transposon that has shown to efficiently insert transgenes into heterologous mammalian chromosomes. The Cre-loxP system is frequently used to delete a given sequence from the genome or to target the integration of foreign DNA. The use of both systems in combination, however, has not yet been …

The Bvg Virulence Control System Regulates Biofilm Formation In Bordetella Bronchiseptica, Yasuhiko Irie, Seema Mattoo, Ming H. Yuk

Biology Faculty Publications

Bordetella species utilize the BvgAS (Bordetella virulence gene) two-component signal transduction system to sense the environment and regulate gene expression among at least three phases: a virulent Bvg⁺ phase, a nonvirulent Bvg⁻ phase, and an intermediate Bvgⁱ phase. Genes expressed in the Bvg⁺ phase encode known virulence factors, including adhesins such as filamentous hemagglutinin (FHA) and fimbriae, as well as toxins such as the bifunctional adenylate cyclase/hemolysin (ACY). Previous studies showed that in the Bvgⁱ phase, FHA and fimbriae continue to be expressed, but ACY expression is significantly downregulated. In this report, we determine …