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Volume 12, No. 2, Summer 02 | Return to Table of Contents
2002 Summer Research Fellows
Twenty-two scientists received fellowships this summer to work at the MBL. Their research projects are described below.
Peter Armstrong, Ph.D. is Professor in the Department of Molecular and Cellular Biology at the University of California, Davis. His research focuses on immune defense proteins and defense processes of arthropods that show evolutionary conservation. Specifically, he studies the pentraxin limulin, which he has shown to be the principal mediator of a plasma-based cytolytic system in Limulus polyphemus that lyses foreign cells that contact the blood. The compound, Limulus aM, mediates the recognition and clearance of proteases from the circulation. A defense function shared by arthropods and vertebrates is blood clotting: the formation of a fibrillar extracellular clot that operates to entrap invading microorganisms, preventing their systemic dissemination in the animal and inactivating their toxic products.
Dr. Armstrong was funded by The Laura and Arthur Colwin Endowed Summer Research Fellowship Fund.
Florencia Botto, Ph.D. is a teacher and researcher in the Department of Biology at the Universidad Nacional de Mar del Plata, Mar del Plata, Argentina. The title of her research project is “The role of intertidal burrowing species (e.g., crabs) on the dynamics of organic matter in estuarine environments.” She evaluates the effect of different densities of burrows of the crab, Chasmagnathus granulata, on the origin and quality of resources in estuarine food webs, especially as they might affect the behavior of water flow and particle transport. She uses stable isotope signatures to establish sources of organic matter that support food webs and, in turn, the transport of nutrients in the intertidal zone. Dr. Botto believes this knowledge will help support conservation decisions.
Dr. Botto was funded by the MBL Associates, The Catherine Filene Shouse Foundation, and the Lucy B. Lemann Fellowship Fund.
J. Peter H. Burbach, Ph.D. is the Director of Research in the Department of Pharmacology and Anatomy at the Rudolf Magnus Institute for Neurosciences University Medical Center, Utrecht, The Netherlands. The title of his research project is “The stellate ganglion of the squid as a model for neurodevelopment gene cascades.” During last summer’s research, Dr. Burbach cloned and characterized two homeobox genes from the stellate ganglion and determined its expression during embryonic development of the squid. These results demonstrated the restricted expression of the POU-homeodomain gene RPF-1 in stellate ganglion neurons and suggested a role in the specification of the giant fiber systems of the squid. This summer he proposes to (1) describe the spatiotemporal expression of forkhead transcription factors during development of the squid stellate ganglion, and in the adult ganglion, and (2) test the injection of morpholinos for the identified homeobox and forkhead transcription factors and consequences for embryonic development.
Dr. Burbach was funded by The Stephen W. Kuffler Fellowship Fund and the Baxter Postdoctoral Fellowship Fund.
David Burgess, Ph.D. is a Professor of Biology at Boston College, Chestnut Hill, Massachusetts. The title of his research project is “Cytokinesis in embryonic cells.” He is interested in how cells form or change shape and how that is precisely regulated using the cytoskeleton. Specifically, he studies how timing and placement of the contractile ring is coupled to mitotic controls in cell division. Investigations are underway on the timing of cytokinesis as a function of the delivery of a positive cleavage stimulus to the cortical cytoskeleton. He also investigates the response system orchestrating the assembly and dynamics of the contractile ring. He is following up on work begun last summer and working on the role of cortical flow as a mediator of contractile ring constriction. His primary research organisms are sea urchins and sand dollars.
Dr. Burgess was funded by the Josiah Macy, Jr. Foundation, the Robert Day Allen Fellowship Fund, and the William Townsend Porter Foundation.
Maristela Camargo, D.V.M., Ph.D. is an Associate Professor in the Pharmacology Department of the Biomedical Sciences Institute at the University São Paulo, São Paulo, Brazil. The title of her research project is “An evolutive study of Th1/Th2 differentiation.” The study of the immune system in a comparative fashion is a powerful tool to assess the functioning of specific cellular circuits through evolution. Dr. Camargo seeks to understand how, when, and why did Th1/Th2 immune responses arise in evolution by studying cartilaginous fish T-like cells, the first to appear in evolution. She is cloning the genes for interleukin-4 and Interferon-gamma in the cartilaginous fish, Raja sp. and Squalus acanthis, by use of degenerated PCR technique. She then plans on identifying “Th1/Th2”-like cells and the signaling pathways involved in the phenotype differentiation. Dr. Camargo believes that the signaling pathways activated upon the engagement of cytokine receptors in these animals might be less redundant when compared to the mouse. Knowledge of the mechanisms controlling the differentiation of Thp lymphocytes into Th1/Th2 is crucial for the understanding of the regulation of normal and oncogenic differentiation, the ability to manipulate the immune system, and the potential development of drugs to control immune responses.
Dr. Camargo was funded by The Catherine Filene Shouse Foundation, The Frederik B. Bang Fellowship Fund, and an MBL Research Fellowship.
Cecilia M. Canessa, M.D. is an Assistant Professor in the Department of Cellular and Molecular Physiology and Medicine at Yale University in New Haven, Connecticut. The title of her research project is “Cloning and characterization of ASIC channels in marine vertebrates.” She investigates how animals have developed sensory modalities to adapt to diverse surroundings and environmental conditions. Specifically, she studies a novel family of ion channels that have been cloned from the mammalian nervous system and how members of this family, known as ASIC, seem to function as mechanoreceptors or nociceptors in sensory neurons. Dr. Canessa has cloned the genes that encode these proton-activated currents in the mammalian model. Her experiments focus on whether ASICs are present in marine vertebrates using Elasmobranchs and Cyclostomes. This work will allow scientists to compare functional properties of the mammalian ASICs with the ones from evolutionarily distant species. The overall goal of this project is to examine the functional role of the ASICs in the transduction of touch and pain in vertebrates.
Dr. Canessa was funded by The Erik B. Fries Endowed Fellowship, the M.G.F. Fuortes Memorial Fellowship Fund, The Stephen W. Kuffler Fellowship Fund, an MBL Research Fellowship, and the Ann E. Kammer Memorial Fellowship Fund.
Fred Chang, M.D., Ph.D. is an Assistant Professor in the Department of Microbiology at Columbia University College of Physicians and Surgeons, New York, New York. The title of his research project is “Placement of the cell division plane.” He is interested in the fundamental question of how the cell division plane is established. His research focuses on defining the molecular pathway by which microtubules establish cell polarity, placement of the actin-based contractile ring, and other activities related to cytokinesis such as membrane insertion and stabilization of the furrow. Dr. Chang studies cell polarity at the cell tips of fission yeast, Schizosaccharo-myces pombe. At the onset of anaphase, astral microtubules grow out from the spindle poles and reach the cell cortex and the cell division plane is established. He analyzes the behavior of microtubule plus ends in anaphase as the cleavage plane is being determined by injecting GFP-tubulin or GFP-EB1 into cells to visualize microtubule plus ends. Cells are then imaged using a spinning disk confocal microscope for optimal spatial and temporal resolution. These studies address fundamental questions in cell biology that will be relevant to diseases such as cancer.
Dr. Chang was funded by The Universal Imaging Corporation Fellowship Fund.
Karen Crawford, Ph.D. is an Associate Professor in the Department of Biology at St. Mary’s College of Maryland, St. Mary’s City, Maryland. Her research project is titled “Molecular analysis of B-catenin expression, axes formation and early embryogenesis in the squid, Loligo pealei, insights into evolution.” Her work involves understanding the mechanisms of squid embryogenesis and development and how they are similar and different to other organisms. Using in vitro culture methods that she perfected at the MBL last summer, she is manipulating embryos at various stages of development from fertilization to hatching by microinjecting them with lineage tracing dyes or specific modifiers of developmental processes or regulators of gene cascades such as RNAs, morpholinos, or transgenes. She is particularly interested in the development and differentiation within the nervous system and is studying homeobox and forkhead genes and the visual Pax 6 gene. The primary objective of this application is to determine the role of B-catenin during axes formation and early development in the squid embryo. These studies will employ advanced biological imaging to create a pictorial atlas of squid development.
Dr. Crawford was funded by the Evelyn and Melvin Spiegel Fellowship Fund, the MBL Associates, and the James A. and Faith Miller Fellowship Fund.
Bonny Dickinson, Ph.D. is an Instructor of Pediatrics at Harvard Medical School and is in the Department of G.I. Cell Biology at Children’s Hospital, Boston, Massachusetts. The title of her research project this summer is “Calmodulin and the unconventional myosins play key regulatory roles in FcRn trafficking by mediating interaction with the actin cytoskeleton.” The goal of this research is to examine the role of two cytoskeletal-associated proteins, calmodulin and the unconventional myosins, as regulators of receptor trafficking in polarized epithelial cells. Calmodulin is the best characterized and most abundant calcium-sensing protein expressed in virtually all eukaryotic cells. Recently, a role for calmodulin in regulating membrane trafficking has been described in both mammalian cells and yeast. Using confocal microscopy, fluorescence resonance energy transfer (FRET), and immunocytochemistry, she studies how FcRn mediates intestinal absorption.
Dr. Dickinson was funded by The Laura and Arthur Colwin Endowed Summer Research Fellowship, The Frederik B. Bang Fellowship Fund, the MBL Associates, and an MBL Research Fellowship.
John K. Douglass, Ph.D. is a Research Associate in the Division of Neurobiology at the Arizona Research Laboratories, University of Arizona, Tucson. The title of his research project is “An electrophysiological and anatomical study of central visual pathways in Limulus polyphemus.” The goal of his project is to learn how the brain of a horseshoe crab (Limulus) is able to interpret the world as seen through its visual system. While the crab watches a computerized “video” that is designed to test its visual capabilities, Dr. Douglass eavesdrops on the signals that single nerve cells relay among different brain centers. The experiments will also reveal the shapes of these nerve cells, allowing him to understand their anatomy within the context of the overall architecture of the brain. Finally, data from single cells is being combined to reveal what kinds of “neural images” the brain abstracts from its raw visual inputs. By learning how the crab’s brain portrays these inputs, he expects to gain new insights into how all animals with eyes make visual sense of the world.
Dr. Douglass was funded by the H. Keffer Hartline Fellowship Fund, the Plum Foundation, John E. Dowling Fellowship Fund, and the Herbert W. Rand Fellowship.
Jan Ellenberg, Ph.D. is an Interdisciplinary Group Leader in the Gene Expression and Cell Biology/Biophysics Programmes at the European Molecular Biology Laboratory, Heidelberg, Germany. His research project is titled “Mechanism of nuclear envelope breakdown (NEBD) in echinoderm oocytes and embryos.” He has been studying NEBD in mitotic somatic mammalian cells over the last two years and has demonstrated a mechanical mechanism by which the nuclear envelope is torn by cytoplasmic spindle microtubules. Dr. Ellenberg is working with Mark Terasaki to characterize NEBD during meiosis in starfish oocytes because of the cell cycle and nuclear architecture in this type of cell. He also studies mitotic embryonic cells of sea urchins. Because of the key role for microtubules in triggering NEBD, he analyzes the dynamics of the cytoskeleton during maturation using fluorescently labeled tubulin and GFP tagged actin to monitor NEBD. These studies will allow him to compare similarities and differences in the mechanism of NEBD between echinoderm oocytes and embryos as well as somatic mammalian cells.
Dr. Ellenberg was the 2002 Nikon Fellow, funded by Nikon Instruments, Inc.
Sarah Garber, Ph.D. is an Associate Professor in the Department of Physiology and Biophysics at the Chicago Medical School, North Chicago, Illinois. The title of her research project is “Correlation of ion flux and regulation of cell volume.” She studies volume regulation in response to a hyposomotic challenge that requires the movement of anions and cations followed by osmotically obligated water. In most mammalian cells studied, the flow of chloride is thought to be initiated by cell swelling resulting in the subsequent activation of swelling-regulated anion channels. This serves to depolarize the cell and activate voltage-dependent potassium channels; thus allowing the flow of osmotically obligated water out of the cell. The amplitude of this current increases with time in response to cell swelling and seems to be affected by amino acids such as glutamate and aspartate. Because glutamate is a neurotransmitter, the release of this molecule during cell volume recovery in brain tissue would result in the activation of glutamate receptors and downstream effects, including the possibility of cell toxicity and death. This suggests there may be a link between homeostatic cell regulatory processes and glutamate activity, under normal and pathological conditions, such as ischemia.
Dr. Garber was funded by The Erik B. Fries Endowed Fellowship.
Yosef Gruenbaum, Ph.D. is Head of the Department of Genetics at the Institute of Life Sciences at The Hebrew University of Jerusalem, Jerusalem, Israel. His research project is titled “Molecular and functional dissection of the nuclear lamina in the surf clam.” The nuclear envelope (NE) is a selective barrier between the nucleus and the cytoplasm composed of outer and inner nuclear membranes, nuclear lamina, and nuclear pores. It is involved in nuclear organization, cell cycle regulation, nuclear migration, transcriptional repression, cell differentiation and apoptosis. Mutations of the lamina give rise to a range of inherited diseases. Dr. Gruenbaum is studying the role of lamin in meiosis by interrupting its assembly and to study the role of other NE proteins in surf clam meiosis. A unique advantage of the surf clam as an experimental system is the ability to study many oocytes undergoing synchronized meiosis and to isolate large numbers of nuclei before and after egg activation as nuclear breakdown takes place.
Dr. Gruenbaum was funded by The Gruss Lipper Foundation, The Frank R. Lillie Fund, The Erik B. Fries Endowed Fellowship, the Robert Day Allen Fellowship Fund, and the H. Burr Steinbach Memorial Fellowship Fund.
Leah Haimo, Ph.D. is an Associate Professor in the Department of Biology at the University of California, Riverside, California. Her research focuses on how molecular motors are regulated to control organelle transport. She uses pigment granule transport in melanophores as a model system to understand how motors that induce force in opposing directions are cyclically activated. Melanophores are transported along microtubules and along actin filaments in response to external stimuli either to the cell center or towards the cell periphery. She will depolymerize actin filaments in melanophores isolated from Fundulus heteroclitus, a fish found in Cape Cod estuaries, and analyze individual organelle transport characteristics to determine how the direction of organelle transport is regulated.
Dr. Haimo was funded by The Laura and Arthur Colwin Endowed Summer Research Fellowship Fund.
Jörg Hardege, Ph.D. is a Senior Lecturer in Chemical Ecology in the Department of Biological Sciences at Hull University, Hull, United Kingdom. The title of his research project is “Do sex pheromone differences in Nereidid polychaetes lead to reproductive isolation?” Pheromone signals are known to coordinate spawning events such as the mass spawning of Nereidid worms in Woods Hole. The project investigates whether these signal molecules are identical in different populations. The study focuses on the potential role of pheromone bouquet differences in the pre-mating isolation in Nereis in order to understand the stability and evolution of chemical signals in terms of population variability and speciation processes. This project also investigates whether inter-population aggression in N. acuminata is based on population-specific chemical signals. Dr. Hardege is also studying the chemical signal composition and responses of Nereis limbata and Platynereis megalops found in Woods Hole populations as compared to European populations. He envisions future studies on how pollutants affect pheromone distribution and how this disruption might “affect” reproduction.
Dr. Hardege was funded by the Lucy B. Lemann Fellowship Fund, The Charles R. Crane Fellowship Fund and The John O. Crane Fellowship Fund.
Mary-Ellen Harper, Ph.D. is an Assistant Professor in the Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine at the University of Ottawa, Ontario, Canada. The title of her research project is “Use and construction of self-referencing microelectro-chemical probes for studies into the role of Uncoupling Protein-3 (UCP3) in myocellular energy metabolism.” The uncoupling proteins are a family of integral membrane proteins found in the mitochondrial inner membrane of most cells of the body. There are thought to be at least five members of the family, each having a unique distribution amongst tissues. UCP3 is expressed almost exclusively in skeletal muscle of humans and there is an important link between UCP3 and energy metabolism. Dr. Harper has hypothesized that the mechanism of UCP3 function involves fatty acid translocation to facilitate continuous high rates of fatty acid oxidation in muscle but recent evidence suggests UCP3 also plays a role in increased glucose metabolism. These findings have important implications for the etiology and potential treatment of insulin resistance and Type 2 diabetes. Dr. Harper is working in the Biocurrents Research Center using a glucose oxidase probe to assess glucose uptake in transfected and non-transfected muscle cells.
Dr. Harper was funded by The Laura and Arthur Colwin Endowed Summer Research Fellowship and the H. Burr Steinbach Memorial Fellowship Fund.
Oscar Iribarne, Ph.D. is a Professor in the Department of Biology at the Universidad Nacional de Mar del Plata, Argentina. The title of his research project is “The role of the SW Atlantic intertidal burrowing crab Chasmagnathus granulata in the dynamics of nutrients.” Benthic fauna play an important role in sedimentary processes leading to changes in marsh and estuarine characteristics. Their burrowing activities have considerable effects on soil aeration and growth and distribution of the flora. Burrowing crabs are present in large numbers in these environments and they have a significant impact on microtopography, sediment chemistry and drainage. Dr. Iribarne evaluates the crabs’ importance as predators, bioturbators, and competitors but emphasizes their most important role is to trap and redirect nutrients reaching the water table. He uses stable isotopes to analyze nutrient dynamics and satellite imaging to identify population densities.
Dr. Iribarne was funded by the Lucy B. Lemann Fellowship Fund.
Diane Lipscombe, Ph.D. is an Associate Professor of Neuroscience in the Division of Biology and Medicine at Brown University, Providence, Rhode Island. The title of her research project is “The identification of novel conus toxins to discriminate among voltage-gated calcium channels and their splice variants.” Voltage-gated calcium channels are expressed in every excitable cell; they regulate a multitude of cellular processes and are targets of many drugs and neuro-transmitters. The stunning degree of diversity among voltage-gated calcium channels, predicted from molecular cloning and database mining, has far outpaced the ability to characterize the various genes and splice variants at the functional and pharmacological levels. Calcium entry through these channels controls neurotransmitter release, neurite outgrowth, gene expression, pacemaking, and muscle contraction. Dr. Lipscombe’s research focuses on screening for novel peptide toxins from venom of different Conus snail species for their ability to inhibit and discriminate among L-type Ca channels and to inhibit and discriminate among splice variants of the N-type Ca channel. The identification of new pharmacological tools that select among the different Ca channel subunits, in particular among L-type Ca channels and among alternative splice variants would be of enormous benefit.
Dr. Lipscombe was funded by The Catherine Filene Shouse Foundation and the MBL Associates.
Ido Perlman, Ph.D. is a Professor in the Department of Physiology and Biophysics, Faculty of Medicine, at the Technion-Israel Institute of Technology, Haifa, Israel. His research project is titled “Nitric oxide synthesis in the vertebrate retina and its physiological and cellular functions.” Visual information processing in the retina is based on a complex array of excitatory and inhibitory synaptic interactions among the various cells. The synaptic interactions are further modulated by neuromodulators to allow the retina to adjust its function to different conditions, e.g. light and dark. One such neuromodulator is nitric oxide (NO), however, NO can also be harmful to the retina due to its interaction with oxygen radicals, causing diseases such as diabetic retinopathy and glaucoma. Dr. Perlman’s research focuses on exploring the influence of different background irradiances upon NO synthesis by the intact retina, studying the interactions between glutamatergic pathways and the NO system, investigating NO synthesis in single retinal cells, and identifying sites of NO action at the cellular level.
Dr. Perlman was funded by The Gruss Lipper Foundation.
Prem Ponka, M.D., Ph.D. is Professor of Physiology and Medicine at McGill University, Montreal, Canada. The title of his research project is “Iron Trafficking in Erythroid Cells: A Collaborative Program.” Iron is an essential nutrient for all cells and tissues. Being an essential element for processes such as oxygen transport, mitochondrial respiration and DNA synthesis, it is also one of the most active producers of toxic radicals, making iron accumulation a lethal cytopathology. Iron found in hemoglobin of red blood cells accounts for up to 70% of the total iron in a normal adult. Therefore, by far, red blood cells have the highest requirement for iron, but our knowledge of iron translocation in developing red blood cells is rather limited. Dr. Ponka investigates the mechanisms involved in the acquisition and intracellular transport of iron in immature red blood cells. He uses various experimental and animal models to identify and characterize the pathway of iron from the cell surface to heme. This research will be very important to understand some of the anemias occurring in humans.
Dr. Ponka was funded by the Frank R. Lillie Fund.
Nancy Ratner, Ph.D. is an Associate Professor in the Department of Cell Biology, Neurobiology and Anatomy at the University of Cincinnati College of Medicine, Cincinnati, Ohio. The title of her research project is “Cyclin-dependent kinases in fast axonal transport.” Dr. Ratner is interested in the role of signaling cascades in the control of cellular trafficking in neurons and the molecular motor proteins that move organelles toward plus or minus ends of microtubules. Specifically, Dr. Ratner investigates the mechanisms whereby cyclin-dependent kinases (cdk) affect actin dynamics and synaptogenesis. She measures vesicle movement using various cdk doses and if effects are observed, will add inhibitors to determine the interaction between the pathways.
Dr. Ratner was funded by the Frank R. Lillie Fund and The Herbert W. Rand Fellowship Fund.
J. Richard Whittaker, Ph.D. is an Adjunct Research Professor of Biology in the Department of Biology at the University of New Brunswick in Fredericton, New Brunswick, Canada. He is a Library Reader this summer and will be working on the major part of a book manuscript titled “The Sea Squirt’s Secret: How We Discovered Our Chordate Ancestry.” This book summarizes the history, biology, and social philosophy behind our 19th Century discovery of protochordates (Amphioxus and the tunicate or “sea squirt” larva). The book examines how we have come to interpret these primitive chordates as surviving representatives of our first chordate ancestors. The book is directed at the so-called “curious non-scientist,” in the recent tradition of popular science books about evolution. He hopes to complete his book by December 31, 2002.
Dr. Whittaker was funded by the Frank A. Brown, Jr. Readership Fund. |
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