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Diversity And Structure Of Bacterial Chemolithotrophic Communities In Pine Forest And Agroecosystem Soils, J. Tolli, G. M. King Dec 2005

Diversity And Structure Of Bacterial Chemolithotrophic Communities In Pine Forest And Agroecosystem Soils, J. Tolli, G. M. King

Faculty Publications

Obligate lithotrophs (e.g., ammonia oxidizers) and facultative lithotrophs (e.g., CO and hydrogen oxidizers) collectively comprise a phylogenetically diverse functional group that contributes significantly to carbon and nitrogen cycles in soils and plays important roles in trace gas dynamics (e.g., carbon monoxide and nitrous and nitric oxides) that affect tropospheric chemistry and radiative forcing. In spite of their diverse physiologies, facultative and obligate lithotrophs typically possess the Calvin-Benson-Bassham cycle enzyme, ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisCO). In an effort designed to understand the structure of lithotrophic communities in soil, genomic DNA extracts from surface (0 to 2 cm) and subsurface (5 to 7 cm) …

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Glycosylphosphatidylinositol-Anchored Proteins Are Required For Cell Wall Synthesis And Morphogenesis In Arabidopsis, C. Stewart Gillmor, Wolfgang Lukowitz, Ginger Brininstool, John C. Sedbrook, Thorsten Hamann, Patricia Poindexter, Chris Somerville Dec 2005

Glycosylphosphatidylinositol-Anchored Proteins Are Required For Cell Wall Synthesis And Morphogenesis In Arabidopsis, C. Stewart Gillmor, Wolfgang Lukowitz, Ginger Brininstool, John C. Sedbrook, Thorsten Hamann, Patricia Poindexter, Chris Somerville

Faculty Publications

Mutations at five loci named PEANUT1-5 (PNT) were identified in a genetic screen for radially swollen embryo mutants, pnt1 cell walls showed decreased crystalline cellulose, increased pectins, and irregular and ectopic deposition of pectins, xyloglucans, and callose. Furthermore, pnt1 pollen is less viable than the wild type, and pnt1 embryos were delayed in morphogenesis and showed defects in shoot and root meristems. The PNT1 gene encodes the Arabidopsis thaliana homolog of mammalian PIG-M, an endoplasmic reticulum-localized mannosyltransferase that is required for synthesis of the glycosylphosphatidylinositol (GPI) anchor. All five pnt mutants showed strongly reduced accumulation of GPI-anchored proteins, suggesting that …

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Cryopreservation Of Human Hematopoietic Stem And Progenitor Cells Loaded With Trehalose: Transient Permeabilization Via The Adenosine Triphosphate-Dependent P2z Receptor Channel, Sandhya S. Buchanan, Michael A. Menze, Steven C. Hand, David W. Pyatt, John F. Carpenter Dec 2005

Cryopreservation Of Human Hematopoietic Stem And Progenitor Cells Loaded With Trehalose: Transient Permeabilization Via The Adenosine Triphosphate-Dependent P2z Receptor Channel, Sandhya S. Buchanan, Michael A. Menze, Steven C. Hand, David W. Pyatt, John F. Carpenter

Faculty Publications

Hematopoietic stem and progenitor cells (HPCs) are a heterogenic population of cells used to treat a number of human diseases. Multilineage differentiation is a required function in successful hematopoietic reconstitution after transplantation of cryopreserved grafts. Conventional use of the cryoprotectant dimethyl sulfoxide (DMSO) has resulted in some reports of infusion related toxicity attributed to DMSO and/or damage to cells during freeze-thawing procedures. The purpose of this study was to explore the use of trehalose, a nontoxic disaccharide of glucose, as an alternative cryoprotectant. Trehalose was introduced into HPCs using the P2Z receptor, known to form nonselective pores in the presence …

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Importance Of Race/Ethnicity In Clinical Trials: Lessons From The African-American Heart Failure Trial (A-Heft), The African-American Study Of Kidney Disease And Hypertension (Aask), And The Antihypertensive And Lipid-Lowering Treatment To Prevent Heart Attack Trial (Allhat), Anne L. Taylor, Jackson T. Wright, Richard S. Cooper Dec 2005

Importance Of Race/Ethnicity In Clinical Trials: Lessons From The African-American Heart Failure Trial (A-Heft), The African-American Study Of Kidney Disease And Hypertension (Aask), And The Antihypertensive And Lipid-Lowering Treatment To Prevent Heart Attack Trial (Allhat), Anne L. Taylor, Jackson T. Wright, Richard S. Cooper

Faculty Publications

No abstract provided.

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A Mobile Element Based Phylogeny Of Old World Monkeys, Jinchuan Xing, Hui Wang, Kyudong Han, David A. Ray, Cheney H. Huang, Leona G. Chemnick, Caro Beth Stewart, Todd R. Disotell, Oliver A. Ryder, Mark A. Batzer Dec 2005

A Mobile Element Based Phylogeny Of Old World Monkeys, Jinchuan Xing, Hui Wang, Kyudong Han, David A. Ray, Cheney H. Huang, Leona G. Chemnick, Caro Beth Stewart, Todd R. Disotell, Oliver A. Ryder, Mark A. Batzer

Faculty Publications

SINEs (Short INterspersed Elements) are a class of non-autonomous mobile elements that are states, making them useful genetic systems for phylogenetic studies. Alu elements are the most successful SINE in primate genomes and have been utilized for resolving primate phylogenetic relationships and human population genetics. However, no Alu based phylogenetic analysis has yet been performed to resolve relationships among Old World monkeys. Using both a computational approach and polymerase chain reaction display methodology, we identified 285 new Alu insertions from sixteen Old World monkey taxa that were informative at various levels of catarrhine phylogeny. We have utilized these elements along …

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Mutation Of Sac1, An Arabidopsis Sac Domain Phosphoinositide Phosphatase, Causes Alterations In Cell Morphogenesis, Cell Wall Synthesis, And Actin Organization, Ruiqin Zhong, David H. Burk, C. Joseph Nairn, Alicia Wood-Jones, W. Herbert Morrison, Zheng Hua Ye Dec 2005

Mutation Of Sac1, An Arabidopsis Sac Domain Phosphoinositide Phosphatase, Causes Alterations In Cell Morphogenesis, Cell Wall Synthesis, And Actin Organization, Ruiqin Zhong, David H. Burk, C. Joseph Nairn, Alicia Wood-Jones, W. Herbert Morrison, Zheng Hua Ye

Faculty Publications

SAC (for suppressor of actin) domain proteins in yeast and animals have been shown to modulate the levels of phosphoinositides, thereby regulating several cellular activities such as signal transduction, actin cytoskeleton organization, and vesicle trafficking. Nine genes encoding SAC domain-containing proteins are present in the Arabidopsis thaliana genome, but their roles in plant cellular functions and plant growth and development have not been characterized. In this report, we demonstrate the essential roles of one of the Arabidopsis SAC domain proteins, AtSAC1, in plant cellular functions. Mutation of the AtSAC1 gene in the fragile fiber7 (fra7) mutant caused a dramatic decrease …

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Insights From The X-Ray Crystal Structure Of Coral 8r-Lipoxygenase: Calcium Activation Via A C2-Like Domain And A Structural Basis Of Product Chirality, Michael L. Oldham, Alan R. Brash, Marcia E. Newcomer Nov 2005

Insights From The X-Ray Crystal Structure Of Coral 8r-Lipoxygenase: Calcium Activation Via A C2-Like Domain And A Structural Basis Of Product Chirality, Michael L. Oldham, Alan R. Brash, Marcia E. Newcomer

Faculty Publications

Lipoxygenases (LOXs) catalyze the regio- and stereospecific dioxygenation of polyunsaturated membrane-embedded fatty acids. We report here the 3.2 Å resolution structure of 8R-LOX from the Caribbean sea whip coral Plexaura homomalla, a LOX isozyme with calcium dependence and the uncommon R chiral stereospecificity. Structural and spectroscopic analyses demonstrated calcium binding in a C2-like membrane-binding domain, illuminating the function of similar amino acids in calcium-activated mammalian 5-LOX, the key enzyme in the pathway to the pro-inflammatory leukotrienes. Mutation of Ca2+- ligating amino acids in 8R-LOX resulted not only in a diminished capacity to bind membranes, as monitored by fluorescence resonance energy …

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Association Of The 17-Kda Extrinsic Protein With Photosystem Ii In Higher Plants, Glen D. Meades, Anne Mclachlan, Larry Sallans, Patrick A. Limbach, Laurie K. Frankel, Terry M. Bricker Nov 2005

Association Of The 17-Kda Extrinsic Protein With Photosystem Ii In Higher Plants, Glen D. Meades, Anne Mclachlan, Larry Sallans, Patrick A. Limbach, Laurie K. Frankel, Terry M. Bricker

Faculty Publications

The structural association of the spinach 17-kDa extrinsic protein of photosystem II with other extrinsic and membrane-bound components of the photosystem was investigated by labeling the 17-kDa extrinsic protein with the amino-group-specific reagent N-hydroxysuccinimidobiotin both on intact photosystem II membranes or as a free protein in solution. After isolation of the biotinylated molecules, the modified 17-kDa proteins were allowed to rebind to photosystem II membranes which were depleted of the 17-kDa component. Differential binding of the protein biotinylated in solution compared to unmodified 17-kDa protein or 17-kDa protein modified on PSII membranes was observed. This indicated possible steric or ionic …

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Detection Of Homocysteine And Cysteine, Weihua Wang, Oleksandr Rusin, Xiangyang Xu, Kyu Kwang Kim, Jorge O. Escobedo, Sayo O. Fakayode, Kristin A. Fletcher, Mark Lowry, Corin M. Schowalter, Candace M. Lawrence, Frank R. Fronczek, Isiah M. Warner, Robert M. Strongin Nov 2005

Detection Of Homocysteine And Cysteine, Weihua Wang, Oleksandr Rusin, Xiangyang Xu, Kyu Kwang Kim, Jorge O. Escobedo, Sayo O. Fakayode, Kristin A. Fletcher, Mark Lowry, Corin M. Schowalter, Candace M. Lawrence, Frank R. Fronczek, Isiah M. Warner, Robert M. Strongin

Faculty Publications

At elevated levels, homocysteine (Hcy, 1) is a risk factor for cardiovascular diseases, Alzheimer's disease, neural tube defects, and osteoporosis. Both 1 and cysteine (Cys, 3) are linked to neurotoxicity. The biochemical mechanisms by which 1 and 3 are involved in disease states are relatively unclear. Herein, we describe simple methods for detecting either Hey or Cys in the visible spectral region with the highest selectivity reported to date without using biochemical techniques or preparative separations. Simple methods and readily available reagents allow for the detection of Cys and Hey in the range of their physiologically relevant levels. New HPLC …

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Trehalose Loading Through The Mitochondrial Permeability Transition Pore Enhances Desiccation Tolerance In Rat Liver Mitochondria, Xiang Hong Liu, Alptekin Aksan, Michael A. Menze, Steven C. Hand, Mehmet Toner Nov 2005

Trehalose Loading Through The Mitochondrial Permeability Transition Pore Enhances Desiccation Tolerance In Rat Liver Mitochondria, Xiang Hong Liu, Alptekin Aksan, Michael A. Menze, Steven C. Hand, Mehmet Toner

Faculty Publications

Trehalose has extensively been used to improve the desiccation tolerance of mammalian cells. To test whether trehalose improves desiccation tolerance of mammalian mitochondria, we introduced trehalose into the matrix of isolated rat liver mitochondria by reversibly permeabilizing the inner membrane using the mitochondrial permeability transition pore (MPTP). Measurement of the trehalose concentration inside mitochondria using high performance liquid chromatography showed that the sugar permeated rapidly into the matrix upon opening the MPTP. The concentration of intra-matrix trehalose reached 0.29 mmol/mg protein (∼190 mM) in 5 min. Mitochondria, with and without trehalose loaded into the matrix, were desiccated in a buffer …

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Host-Parasitoid Spatial Ecology: A Plea For A Landscape-Level Synthesis, James T. Cronin, John D. Reeve Nov 2005

Host-Parasitoid Spatial Ecology: A Plea For A Landscape-Level Synthesis, James T. Cronin, John D. Reeve

Faculty Publications

A growing body of literature points to a large-scale research approach as essential for understanding population and community ecology. Many of our advances regarding the spatial ecology of predators and prey can be attributed to research with insect parasitoids and their hosts. In this review, we focus on the progress that has been made in the study of the movement and population dynamics of hosts and their parasitoids in heterogeneous landscapes, and how this research approach may be beneficial to pest management programs. To date, few studies have quantified prey and predator rates and ranges of dispersal and population dynamics …

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Multiple Bromodomain Genes Are Involved In Restricting The Spread Of Heterochromatic Silencing At The Saccharomyces Cerevisiae Hmr-Trna Boundary, Nithya Jambunathan, Adam W. Martinez, Elizabeth C. Robert, Nneamaka B. Agochukwu, Megan E. Ibos, Sandra L. Dugas, David Donze Nov 2005

Multiple Bromodomain Genes Are Involved In Restricting The Spread Of Heterochromatic Silencing At The Saccharomyces Cerevisiae Hmr-Trna Boundary, Nithya Jambunathan, Adam W. Martinez, Elizabeth C. Robert, Nneamaka B. Agochukwu, Megan E. Ibos, Sandra L. Dugas, David Donze

Faculty Publications

The transfer RNA gene downstream from the HMR locus in S. cerevisiae functions as part of a boundary (barrier) element that restricts the spread of heterochromatic gene silencing into the downstream region of chromosome III. A genetic screen for identifying additional genes that, when mutated, allow inappropriate spreading of silencing from HMR through the tRNA gene was performed. YTA7, a gene containing bromodomain and ATPase homologies, was identified multiple times. Previously, others had shown that the bromodomain protein Bdf1p functions to restrict silencing at yeast euchromatin- heterochromatin boundaries; therefore we deleted nonessential bromodomain-containing genes to test their effects on heterochromatin …

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The Case For Selection At Ccr5-Δ32, Pardis C. Sabeti, Emily Walsh, Steve F. Schaffner, Patrick Varilly, Ben Fry, Holli B. Hutcheson, Mike Cullen, Tarjei S. Mikkelsen, Jessica Roy, Nick Patterson, Richard Cooper, David Reich, David Altshuler, Stephen O'Brien, Eric S. Lander Nov 2005

The Case For Selection At Ccr5-Δ32, Pardis C. Sabeti, Emily Walsh, Steve F. Schaffner, Patrick Varilly, Ben Fry, Holli B. Hutcheson, Mike Cullen, Tarjei S. Mikkelsen, Jessica Roy, Nick Patterson, Richard Cooper, David Reich, David Altshuler, Stephen O'Brien, Eric S. Lander

Faculty Publications

The C-C chemokine receptor 5, 32 base-pair deletion (CCR5-Δ32) allele confers strong resistance to infection by the AIDS virus HIV. Previous studies have suggested that CCR5-Δ32 arose within the past 1,000 y and rose to its present high frequency (5%-14%) in Europe as a result of strong positive selection, perhaps by such selective agents as the bubonic plague or smallpox during the Middle Ages. This hypothesis was based on several lines of evidence, including the absence of the allele outside of Europe and long-range linkage disequilibrium at the locus. We reevaluated this evidence with the benefit of much denser genetic …

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Successful Island Reintroductions Of New Zealand Robins And Saddlebacks With Small Numbers Of Founders, Sabrina S. Taylor, Ian G. Jamieson, Doug P. Armstrong Nov 2005

Successful Island Reintroductions Of New Zealand Robins And Saddlebacks With Small Numbers Of Founders, Sabrina S. Taylor, Ian G. Jamieson, Doug P. Armstrong

Faculty Publications

Populations established with a small number of founders are thought to have a high risk of extinction due to Allee effects, demographic stochasticity, inbreeding and reduced genetic variation. We tested whether the initial number of birds released was related to persistence in reintroductions of saddlebacks (Philesturnus carunculatus) and robins (Petroica australis) to New Zealand offshore islands. Data were analysed for 31 populations that had been observed for at least 3 years since reintroductions. The numbers released ranged from 5-188. Most of the populations (26) survived and grew, including five from less than 15 founders, and four out of the five …

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Bioassay-Guided Fractionation Of Rubus Suavissimus Leaf Extracts Possessing Nf-Κb Inhibitory Activities And A Separable Cytotoxicity, Dong Liu, Zhanguo Gao, Jian Zhang, Jianping Ye, Zhijun Liu Nov 2005

Bioassay-Guided Fractionation Of Rubus Suavissimus Leaf Extracts Possessing Nf-Κb Inhibitory Activities And A Separable Cytotoxicity, Dong Liu, Zhanguo Gao, Jian Zhang, Jianping Ye, Zhijun Liu

Faculty Publications

Leaf extract of Rubus suavissimus S. Lee (Rosaceae), a perennial woody shrub indigenous to southern China, was tested for its biological activity in the regulation of transcription factor NF-κB (nuclear factor kappa B) A NF-κB luciferase reporter cell line was used in this study. The crude extract inhibited NF-κB at 100-1000 μg/ml concentrations with minor cytotoxicity. This finding prompted two more rounds of fractionation toward separating the active fraction from the cytotoxic fraction. Five fractions were obtained in the first round of fractionation, of which RUS-C20 was found to be the most potent in inhibiting NF-κB without signs of cytotoxicity …

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Genomic Rearrangements By Line-1 Insertion-Mediated Deletion In The Human And Chimpanzee Lineages, Kyudong Han, Shurjo K. Sen, Jianxin Wang, Pauline A. Callinan, Jungnam Lee, Richard Cordaux, Ping Liang, Mark A. Batzer Oct 2005

Genomic Rearrangements By Line-1 Insertion-Mediated Deletion In The Human And Chimpanzee Lineages, Kyudong Han, Shurjo K. Sen, Jianxin Wang, Pauline A. Callinan, Jungnam Lee, Richard Cordaux, Ping Liang, Mark A. Batzer

Faculty Publications

Long INterspersed Elements (LINE-1s or L1s) are abundant non-LTR retrotransposons in mammalian genomes that are capable of insertional mutagenesis. They have been associated with target site deletions upon insertion in cell culture studies of retrotransposition. Here, we report 50 deletion events in the human and chimpanzee genomes directly linked to the insertion of L1 elements, resulting in the loss of ∼18 kb of sequence from the human genome and ∼15 kb from the chimpanzee genome. Our data suggest that during the primate radiation, L1 insertions may have deleted up to 7.5 Mb of target genomic sequences. While the results of …

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A Role For Airway Remodeling During Respiratory Syncytial Virus Infection, David Becnel, Dahui You, Joshua Erskin, Dawn M. Dimina, Stephania A. Cormier Oct 2005

A Role For Airway Remodeling During Respiratory Syncytial Virus Infection, David Becnel, Dahui You, Joshua Erskin, Dawn M. Dimina, Stephania A. Cormier

Faculty Publications

Background: Severe respiratory syncytial virus infection (RSV) during infancy has been shown to be a major risk factor for the development of subsequent wheeze. However, the reasons for this link remain unclear. The objective of this research was to determine the consequences of early exposure to RSV and allergen in the development of subsequent airway hyperreactivity (AHR) using a developmental time point in the mouse that parallels that of the human neonate. Methods: Weanling mice were sensitized and challeged with ovalbumin (Ova) and/or infected with RSV. Eight days after the last allergen challenge, various pathophysiological endpoints were examined. Results: AHR …

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Limitations And Potentials Of Current Motif Discovery Algorithms, Jianjun Hu, Bin Li, Daisuke Kihara Oct 2005

Limitations And Potentials Of Current Motif Discovery Algorithms, Jianjun Hu, Bin Li, Daisuke Kihara

Faculty Publications

Computational methods for de novo identification of gene regulation elements, such as transcription factor binding sites, have proved to be useful for deciphering genetic regulatory networks. However, despite the availability of a large number of algorithms, their strengths and weaknesses are not sufficiently understood. Here, we designed a comprehensive set of performance measures and benchmarked five modern sequence-based motif discovery algorithms using large datasets generated from Escherichia coli RegulonDB. Factors that affect the prediction accuracy, scalability and reliability are characterized. It is revealed that the nucleotide and the binding site level accuracy are very low, while the motif level accuracy …

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Cross-Talk Among Gp130 Cytokines In Adipocytes, Sanjin Zvonic, James E. Baugh, Patricia Arbour-Reily, Randall L. Mynatt, Jacqueline M. Stephens Oct 2005

Cross-Talk Among Gp130 Cytokines In Adipocytes, Sanjin Zvonic, James E. Baugh, Patricia Arbour-Reily, Randall L. Mynatt, Jacqueline M. Stephens

Faculty Publications

The interleukin-6 (IL-6) family of cytokines is a family of structurally and functionally related proteins, including IL-6, IL-11, leukemia inhibitory factor (LIF), oncostatin M (OSM), ciliary neurotrophic factor (CNTF), and cardiotrophin-1 (CT-1). These proteins are also known as gp130 cytokines because they all share gp130 as a common transducer protein within their functional receptor complexes. Several of these cytokines (LIF, OSM, CNTF, and CT-1) also utilize the LIF receptor (LIFR) as a component of their receptor complex. We have shown that all of these cytokines are capable of activating both the JAK/STAT and p42/44 mitogen-activated protein kinase signaling pathways in …

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Tracking Alu Evolution In New World Primates, David A. Ray, Mark A. Batzer Oct 2005

Tracking Alu Evolution In New World Primates, David A. Ray, Mark A. Batzer

Faculty Publications

Background: Alu elements are Short INterspersed Elements (SINEs) in primate genomes that have proven useful as markers for studying genome evolution, population biology and phylogenetics. Most of these applications, however, have been limited to humans and their nearest relatives, chimpanzees. In an effort to expand our understanding of Alu sequence evolution and to increase the applicability of these markers to non-human primate biology, we have analyzed available Alu sequences for loci specific to platyrrhine (New World) primates. Results: Branching patterns along an Alu sequence phylogeny indicate three major classes of platyrrhine-specific Alu sequences. Sequence comparisons further reveal at least three …

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Modulation Of Yeast Genome Expression In Response To Defective Rna Polymerase Iii-Dependent Transcription, Christine Conesa, Roberta Ruotolo, Pascal Soularue, Tiffany A. Simms, David Donze, André Sentenac, Giorgio Dieci Oct 2005

Modulation Of Yeast Genome Expression In Response To Defective Rna Polymerase Iii-Dependent Transcription, Christine Conesa, Roberta Ruotolo, Pascal Soularue, Tiffany A. Simms, David Donze, André Sentenac, Giorgio Dieci

Faculty Publications

We used genome-wide expression analysis in Saccharomyces cerevisiae to explore whether and how the expression of protein-coding, RNA polymerase (Pol) II-transcribed genes is influenced by a decrease in RNA Pol III-dependent transcription. The Pol II transcriptome was characterized in four thermosensitive, slow-growth mutants affected in different components of the RNA Pol III transcription machinery. Unexpectedly, we found only a modest correlation between altered expression of Pol II-transcribed genes and their proximity to class III genes, a result also confirmed by the analysis of single tRNA gene deletants. Instead, the transcriptome of all of the four mutants was characterized by increased …

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Cellular Efflux Of Auxin Catalyzed By The Arabidopsis Mdr/Pgp Transporter Atpgp1, Markus Geisler, Joshua J. Blakeslee, Rodolphe Bouchard, Ok Ran Lee, Vincent Vincenzetti, Anindita Bandyopadhyay, Boosaree Titapiwatanakun, Wendy Ann Peer, Aurèlien Bailly, Elizabeth L. Richards, Karin F.K. Ejendal, Aaron P. Smith, Célia Baroux, Ueli Grossniklaus, Axel Müller, Christine A. Hrycyna, Robert Dudler, Angus S. Murphy, Enrico Martinoia Oct 2005

Cellular Efflux Of Auxin Catalyzed By The Arabidopsis Mdr/Pgp Transporter Atpgp1, Markus Geisler, Joshua J. Blakeslee, Rodolphe Bouchard, Ok Ran Lee, Vincent Vincenzetti, Anindita Bandyopadhyay, Boosaree Titapiwatanakun, Wendy Ann Peer, Aurèlien Bailly, Elizabeth L. Richards, Karin F.K. Ejendal, Aaron P. Smith, Célia Baroux, Ueli Grossniklaus, Axel Müller, Christine A. Hrycyna, Robert Dudler, Angus S. Murphy, Enrico Martinoia

Faculty Publications

Directional transport of the phytohormone auxin is required for the establishment and maintenance of plant polarity, but the underlying molecular mechanisms have not been fully elucidated. Plant homologs of human multiple drug resistance/P-glycoproteins (MDR/PGPs) have been implicated in auxin transport, as defects in MDR1 (AtPGP19) and AtPGP1 result in reductions of growth and auxin transport in Arabidopsis (atpgp1, atpgp19), maize (brachytic2) and sorghum (dwarf3). Here we examine the localization, activity, substrate specificity and inhibitor sensitivity of AtPGP1. AtPGP1 exhibits non-polar plasma membrane localization at the shoot and root apices, as well as polar localization above the root apex. Protoplasts from …

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Hurricane-Forced Upwelling And Chlorophyll A Enhancement Within Cold-Core Cyclones In The Gulf Of Mexico, Nan D. Walker, Robert R. Leben, Shreekanth Balasubramanian Sep 2005

Hurricane-Forced Upwelling And Chlorophyll A Enhancement Within Cold-Core Cyclones In The Gulf Of Mexico, Nan D. Walker, Robert R. Leben, Shreekanth Balasubramanian

Faculty Publications

Clear skies, subsequent to Hurricane Ivan's passage across the Gulf of Mexico in September 2004, provided a unique opportunity to investigate upper ocean responses to a major hurricane. Oceanic cyclonic circulation was rapidly intensified by the hurricane's wind field (59-62 m s-1), maximizing upwelling and surface cooling (3-7°C) in two large areas along Ivan's track. Upward isothermal displacements of 50-65 m, computed from wind stress and sea surface height changes, caused rapid ventilation of thermoclines and nutriclines, leading to phytoplankton blooms with peak concentrations 3-4 days later. Wind speed changes along Ivan's track demonstrated that the cool waters …

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Modulation Of Synaptic Function In Retinal Amacrine Cells, Brian K. Hoffpauir, Evanna L. Gleason Sep 2005

Modulation Of Synaptic Function In Retinal Amacrine Cells, Brian K. Hoffpauir, Evanna L. Gleason

Faculty Publications

Amacrine cells are interneurons that have diverse functions in retinal signal processing. In order to study signaling and modulation in retinal amacrine cells, we employ a simplified culture system containing identifiable GABAergic amacrine cells. Immunocytochemistry experiments indicate that GABAergic amacrine cells express metabotropic glutamate receptor 5 (mGluR5), a group I mGluR usually linked to the IP3 signaling pathway. Ca2+ imaging experiments using an mGluR5-specific agonist indicate that these receptors are functional and when activated, can stimulate temporally diverse Ca2+ elevations. To begin to establish the role of these receptors in modulating amacrine cell function, we have used electrophysiological methods to …

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A Climate-Based Approach To The Restoration Of Fire-Dependent Ecosystems, Brian Beckage, William J. Platt, Bob Panko Sep 2005

A Climate-Based Approach To The Restoration Of Fire-Dependent Ecosystems, Brian Beckage, William J. Platt, Bob Panko

Faculty Publications

Recurrent fires are integral to the function of many ecosystems worldwide. The management of fire-frequented ecosystems requires the application of fire at the appropriate frequency and seasonally, but establishing the natural fire regime for an ecosystem can be problematic. Historical records of fires are often not available, and surrogates for past fires may not exist. We suggest that the relationship between climate and fire can provide an alternative means for inferring past fire regimes in some ecosystems. © 2005 Society for Ecological Restoration International.

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Analysis Of The Distribution And Diversity In Recent Hawaiian Volcanic Deposits Of A Putative Carbon Monoxide Dehydrogenase Large Subunit Gene, Kari E. Dunfield, Gary M. King Sep 2005

Analysis Of The Distribution And Diversity In Recent Hawaiian Volcanic Deposits Of A Putative Carbon Monoxide Dehydrogenase Large Subunit Gene, Kari E. Dunfield, Gary M. King

Faculty Publications

A putative carbon monoxide dehydrogenase large subunit gene (BMS putative coxL) was amplified from genomic DNA extracts of four recent (42-300 year old) Hawaiian volcanic deposits by polymerase chain reaction (PCR). Sequence databases derived from clone libraries constructed using PCR products were analysed phylogenetically and statistically. These analyses indicated that each of the deposits supported distinct BMS putative coxL gene assemblages. Statistical analyses also showed that the youngest deposit (42 years old) contained the least diverse sequences (P < 0.05), but that diversity did not vary significantly among three older deposits with ages from about 108-300 years. Although diversity indices did not vary among the older deposits, mismatch analyses suggested population structures increased in complexity with increasing deposit age. At each of the sites, most of the clone sequences appeared to originate from Proteobacteria not currently represented in culture or recognized as CO oxidizers. © 2005 Society for Applied Microbiology and Blackwell Publishing Ltd.

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Status, Trends And Management Of Sturgeon And Paddlefish Fisheries, Ellen K. Pikitch, Phaedra Doukakis, Liz Lauck, Prosanta Chakrabarty, Daniel L. Erickson Sep 2005

Status, Trends And Management Of Sturgeon And Paddlefish Fisheries, Ellen K. Pikitch, Phaedra Doukakis, Liz Lauck, Prosanta Chakrabarty, Daniel L. Erickson

Faculty Publications

The 27 extant species of sturgeons and paddlefishes (Order Acipenseriformes) represent a unique and relict lineage of fishes. Producers of coveted black caviar, sturgeons are one of the most valuable wildlife commodities on earth. The group is among the most endangered fishes with all species listed under Convention on International Trade in Endangered Species (CITES) Appendix I (two species) or II (25 species), only two species considered Lower Risk by IUCN, four of the nine US taxa and one Caspian species protected under the Endangered Species Act, and local extinctions recorded for 19 of 27 species. Despite their well-publicized imperilled …

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Thioredoxin Reductase System Mediates Iron Binding In Isca And Iron Delivery For The Iron-Sulfur Cluster Assembly In Iscu, Huangen Ding, Karyn Harrison, Jianxin Lu Aug 2005

Thioredoxin Reductase System Mediates Iron Binding In Isca And Iron Delivery For The Iron-Sulfur Cluster Assembly In Iscu, Huangen Ding, Karyn Harrison, Jianxin Lu

Faculty Publications

IscA is a key member of the iron-sulfur cluster assembly machinery found in bacteria and eukaryotes. Previously, IscA was characterized as an alternative iron-sulfur cluster assembly scaffold, as purified IscA can host transient iron-sulfur clusters. However, recent studies indicated that IscA is an iron-binding protein that can provide iron for the iron-sulfur cluster assembly in a proposed scaffold IscU (Ding H., Clark, R. J., and Ding, B. (2004) J. Biol. Chem. 279, 37499-37504). To further elucidate the roles of IscA in the biogenesis of iron-sulfur clusters, we reevaluate the iron binding activity of IscA under physiologically relevant conditions. The results …

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Animal Virus Replication And Rnai-Mediated Antiviral Silencing In Caenorhabditis Elegans, R. Lu, M. Maduro, F. Li, H. W. Li, G. Broitman-Maduro, W. X. Li, S. W. Ding Aug 2005

Animal Virus Replication And Rnai-Mediated Antiviral Silencing In Caenorhabditis Elegans, R. Lu, M. Maduro, F. Li, H. W. Li, G. Broitman-Maduro, W. X. Li, S. W. Ding

Faculty Publications

The worm Caenorhabditis elegans is a model system for studying many aspects of biology, including host responses to bacterial pathogens, but it is not known to support replication of any virus. Plants and insects encode multiple Dicer enzymes that recognize distinct precursors of small RNAs and may act cooperatively. However, it is not known whether the single Dicer of worms and mammals is able to initiate the small RNA-guided RNA interference (RNAi) antiviral immunity as occurs in plants and insects. Here we show complete replication of the Flock house virus (FHV) bipartite, plus-strand RNA genome in C. elegans. We show …

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Surface Salt Bridges Modulate The Dna Site Size Of Bacterial Histone-Like Hu Proteins, Edwin Kamau, Nick D. Tsihlis, L. Alice Simmons, Anne Grove Aug 2005

Surface Salt Bridges Modulate The Dna Site Size Of Bacterial Histone-Like Hu Proteins, Edwin Kamau, Nick D. Tsihlis, L. Alice Simmons, Anne Grove

Faculty Publications

Bacterial histone-like DNA-binding proteins are best known for their role in compacting the genomic DNA. Of these proteins, HU is ubiquitous and highly conserved across the eubacterial kingdom. Using the HBsu (Bacillus subtilis-encoded HU homologue) as a model, we explore here the molecular basis for the ability of some HU homologues to engage a longer approx. 35 bp DNA site as opposed to the much shorter sites reported for other homologues. Using electrophoretic mobility-shift assays, we show that the DNA site size for HBsu is approx. 10-13 bp and that a specific surface salt bridge limits the DNA site size …

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