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Puerto Rican Karst - A Vital Resource, Ariel E. Lugo, Leopoldo Miranda Castro, Abel Vale, Tania Del Mar López, Enrique Hernández Prieto, Andrés García Martinó, Alberto R. Puente Rolón, Adrianne G. Tossas, Donald A. Mcfarlane, Tom Miller, Armando Rodríguez, Joyce Lundberg, John Thomlinson, José Colón, Johannes H. Schellekens, Olga Ramos, Eileen Helmer Aug 2001

Puerto Rican Karst - A Vital Resource, Ariel E. Lugo, Leopoldo Miranda Castro, Abel Vale, Tania Del Mar López, Enrique Hernández Prieto, Andrés García Martinó, Alberto R. Puente Rolón, Adrianne G. Tossas, Donald A. Mcfarlane, Tom Miller, Armando Rodríguez, Joyce Lundberg, John Thomlinson, José Colón, Johannes H. Schellekens, Olga Ramos, Eileen Helmer

WM Keck Science Faculty Papers

The limestone region of Puerto Rico covers about 27.5 percent of the island's surface and is subdivided into the northern, southern, and dispersed limestone areas. All limestone areas have karst features. The karst belt is that part of the northern limestone with the most spectacular surficial karst landforms. It covers 142,544 ha or 65 percent of the northern limestone. The karst belt is the focus of this publication, although reference is made to all limestone regions. The northern limestone contains Puerto Rico's most extensive freshwater aquifer, largest continuous expanse of mature forest, and largest coastal wetland, estuary, and underground cave …


Transduction By Phi Bb-1, A Bacteriophage Of Borrelia Burgdorferi, Christian H. Eggers, Betsy J. Kimmel, James L. Bono, Abdallah F. Elias, Patricia Rosa, D. Scott Samuels Aug 2001

Transduction By Phi Bb-1, A Bacteriophage Of Borrelia Burgdorferi, Christian H. Eggers, Betsy J. Kimmel, James L. Bono, Abdallah F. Elias, Patricia Rosa, D. Scott Samuels

Biological Sciences Faculty Publications

We previously described a bacteriophage of the Lyme disease agent Borrelia burgdorferi designated phi BB-1. This phage packages the host complement of the 32-kb circular plasmids (cp32s), a group of homologous molecules found throughout the genus Borrelia. To demonstrate the ability of phi BB-1 to package and transduce DNA, a kanamycin resistance cassette was inserted into a cloned fragment of phage DNA, and the resulting construct was transformed into B. burgdorferi CA-11.2A cells. The kan cassette recombined into a resident cp32 and was stably maintained. The cp32 containing the kan cassette was packaged by phi BB-1 released from this B. …


Restoring Enriched Grasslands: Effects Of Mowing On Species Richness, Productivity, And Nitrogen Retention, John L. Maron, Robert L. Jefferies Aug 2001

Restoring Enriched Grasslands: Effects Of Mowing On Species Richness, Productivity, And Nitrogen Retention, John L. Maron, Robert L. Jefferies

Biological Sciences Faculty Publications

Species-rich grasslands that become enriched with nitrogen often suffer decreases in species richness, increases in plant biomass, and invasion by weedy exotic species. Suitable techniques to restore enriched grasslands and reestablish native communities are increasingly needed. Here we report results of a 5-yr experiment in enriched coastal prairie grasslands (Bodega Marine Reserve, Bodega Bay, California, USA), to determine the combined effects of mowing and biomass removal on total soil nitrogen, net rates of mineralization, nitrogen retention, and species richness and biomass. We mowed and removed plant biomass from plots in areas where the N-fixing shrub, bush lupine (Lupinus arboreus …


Development And Characterization Of Monoclonal Antibodies Directed Against Yaba-Like Disease Virus, Scott Haller Aug 2001

Development And Characterization Of Monoclonal Antibodies Directed Against Yaba-Like Disease Virus, Scott Haller

Masters Theses

The hybridoma technique has been used for the production of monoclonal antibodies (mAb) directed against yaba-like disease virus (YLDV). Spleen cells, obtained from female BALB/c mice immunized with YLDV, were fused with P3x63.Ag8.653 myeloma cells and hybrids were selected. Hybridoma clones were screened for production of anti-YLDV antibodies by Indirect Immunofluorescence (IF) microscopy. Positive hybridoma clones were recloned via limiting dilution and characterized. A single clone (H12) has been selected that specifically reacted with YLDV infected cells and not uninfected cells. Immunodiffusion technique determined H12 monoclonal antibody as an IgG1 isoptype immunoglobulin. H12 antibodies recognized a late YLDV protein, and …


A Heat-Shock-Activated Cdna Encoding Gaga Factor Rescues Some Lethal Mutations In The Drosophila Melanogaster Trithorax-Like Gene, H Granok, B Leibovitch, Sarah C.R. Elgin Aug 2001

A Heat-Shock-Activated Cdna Encoding Gaga Factor Rescues Some Lethal Mutations In The Drosophila Melanogaster Trithorax-Like Gene, H Granok, B Leibovitch, Sarah C.R. Elgin

Biology Faculty Research

GAGA factor is an important chromosomal protein involved in establishing specific nucleosome arrays and in regulating gene transcription in Drosophila melanogaster. We developed a transgenic system for controlled heat-shock-dependent overexpression of the GAGA factor 519 amino acid isoform (GAGA-519) in vivo. Efficient production of stable protein from these transgenes provided genetic rescue of a hypomorphic Trithorax-like (Trl) lethal allele to adulthood. Nevertheless, supplemental GAGA-519 did not suppress position effect variegation (PEV), a phenomenon commonly used to measure dosage effects of chromosomal proteins, nor did it rescue other lethal alleles of Trl. The results suggest requirements for the additional isoforms of …


The Impact Of Logging On Aquatic Salamander Communities., Heather Noel Mcdonald Aug 2001

The Impact Of Logging On Aquatic Salamander Communities., Heather Noel Mcdonald

Electronic Theses and Dissertations

For this study, the abundance of the salamander fauna in two streams was compared to determine the impact of logging activities. After five months of study, the area around one stream was logged by the National Forest Service. Following logging, the abundance of salamanders in the stream was greatly reduced, while the population in the undisturbed stream remained relatively unchanged. Six abundant species were used as indicators; two of these species (Desmognathus quadramaculatus and Desmognathus ochrophaeus) were negatively affected by the logging, while four species (Demognathus fuscus, Desmognathus monticola, Eurycea wilderae, and Gyrinophilus porphyriticus …


The Detection Of Morphological Variation Across Time In Two Roan Mountain Endemics: Geum Radiatum And Houstonia Montana., Dalenia Medford Aug 2001

The Detection Of Morphological Variation Across Time In Two Roan Mountain Endemics: Geum Radiatum And Houstonia Montana., Dalenia Medford

Electronic Theses and Dissertations

Morphological variation between geographically distant populations has long been recognized. The primary objective of this study was to test whether nonrandom shifts in morphology have occurred across a 150-year time span in two rare, endangered plant species Geum radiatum and Houstonia montana. During the last century the vegetation on Roan Mountain has undergone numerous environmental pressures that may have produced morphological shifts.

A diverse suite of morphological characters was measured from both species. Characters included vegetative and reproductive structures. Herbarium specimens and direct field measurements were the sources of material used. Results indicated a significant increase in size across …


Survey And Comparison Of Amphibian Assemblages In Two Physiographic Regions Of Northeast Tennessee., Marquette Elaine Crockett Aug 2001

Survey And Comparison Of Amphibian Assemblages In Two Physiographic Regions Of Northeast Tennessee., Marquette Elaine Crockett

Electronic Theses and Dissertations

Declines in amphibian populations have prompted study of their ecology and distribution. The purpose of this study was to survey two sites located within different physiographic and one herpetofaunal region of Northeast Tennessee, comparing species composition and activity. The first, Henderson Wetland, is in the Appalachian Ridge and Valley physiographic region. The second, John's Bog, is in the Blue Ridge. Survey methods included random walks, aural surveys, and point source collections during a 16-month period (February 1999 to May 2000).

Nine caudate (Plethodontidae) and one anuran species (Ranidae) were found in John's Bog. Seven caudate (Ambystomatidae, Plethodontidae, Salamandridae) and five …


Reproductive Constraints And The Evolution Of Life Histories With Indeterminate Growth, Eric Charnov, Thomas Turner, Kirk Winemiller Jul 2001

Reproductive Constraints And The Evolution Of Life Histories With Indeterminate Growth, Eric Charnov, Thomas Turner, Kirk Winemiller

Biology Faculty & Staff Publications

This article develops a new evolutionary model for life histories by combining a new production-growth model with some general, yet specific, constraints on reproductive allocation, and by allowing natural selection to adjust the age of first breeding and the metabolic/productive capacity of cells. The optimal life histories correctly predict the numeric value of dimensionless numbers that combine maturation age (size), mortality, and reproductive allocation. The life-history prediction also yields a new lifetime growth model for body mass under indeterminate growth and predicts that the fastest growth rate will be near the size at first reproduction. Table 1 is a glossary …


Production Of Cell Wall Enzymes In Pepper Seedlings, Inoculated With Arbuscular Mycorrhiza Glomus Etunicatum, A C Odebode, A O Salami, O Osunubi Jul 2001

Production Of Cell Wall Enzymes In Pepper Seedlings, Inoculated With Arbuscular Mycorrhiza Glomus Etunicatum, A C Odebode, A O Salami, O Osunubi

Tanzania Journal of Science

Pepper seedlings inoculated with arbuscular mycorrhizal AM fungus, Glomus etunicatum, produced cellulase, polygal-acturonase and pectin methylestrase enzymes. The activities of the enzymes increased as the pepper seedlings matured in age, showing that the activity of the enzymes in the seedlings was age mediated. The pectinases showed higher activity than the cellulase enzyme which may indicate establishment of the mycorrhizal in the host. The significance of this finding is that there is an initial infectivity factor in (AM) fungi interactions with plant just like in other host-parasite interaction.


Occurrence And Activity Budget Of The Leopard Tortoise, Geochelone Pardalis, In Northern Tanzania, J Kabigumila Jul 2001

Occurrence And Activity Budget Of The Leopard Tortoise, Geochelone Pardalis, In Northern Tanzania, J Kabigumila

Tanzania Journal of Science

Occurrence and activity budget of the leopard tortoise, Geochelone pardalis were studied in northern Tanzania between October 1993 and June 1996. Tortoises occurred most frequently in short grass (51.5%) and along roads and track verges (33.9%), but only occasionally in the bush undergrowth (6.7%) and shambas (3.6%). Walking (46.3%) and feeding (37.2%) were the most frequent activities. Resting was observed only occasionally (13.6%) while courtship (1.9%) and drinking (0.9%) were rarely recorded. Activity budget differed significantly between the age classes and habitats, but not between the sexes. Juveniles walked more frequently (59.3%) than other age classes. Walking was most frequent …


Avian And Mammalian Use Of Three Small Urban Wetlands Invaded By A Pest Species, Reed Canarygrass (Phalaris Arundinacea L.), Laurie Dizney Jul 2001

Avian And Mammalian Use Of Three Small Urban Wetlands Invaded By A Pest Species, Reed Canarygrass (Phalaris Arundinacea L.), Laurie Dizney

Dissertations and Theses

Small urban wetlands are being destroyed and degraded at an alarming rate. One result of degradation is invasion by pest species, such as reed canarygrass (Phalaris arundinacea L. ). Reed canarygrass forms virtual monocultures in a wide range of wetland types. Wetlands normally have high plant species richness and abundance, which is widely believed to lead to faunal diversity. The purpose of the present study was to determine to what extent birds and mammals use a wetland dominated by reed canarygrass. The research was conducted at Tualatin Hills Nature Park in Beaverton, Washington County, Oregon. I examined three sites …


The Effect Of The El Niño–Southern Oscillation Event On The Distribution Of Reef-Associated Labrid Fishes In The Eastern Pacific Ocean, Benjamin C. Victor, Gerard M. Wellington, D. Ross Robertson, Benjamin I. Ruttenberg Jul 2001

The Effect Of The El Niño–Southern Oscillation Event On The Distribution Of Reef-Associated Labrid Fishes In The Eastern Pacific Ocean, Benjamin C. Victor, Gerard M. Wellington, D. Ross Robertson, Benjamin I. Ruttenberg

Biological Sciences

We surveyed the labrid fishes of the eastern Pacific ocean at multiple sites before, during, and after the 1997–98 ENSO event. Our observations showed that reef fish communities in general did not appear to change markedly as a result of the ENSO. Recruitment of labrids at the Galápagos Islands, Clipperton Atoll and Baja California was generally high near the end of the ENSO, indicating no negative effect on populations. Two labrid species did extend their known range during the ENSO: Stethojulis bandanensis settled onto the tip of Baja California and to the Galápagos Islands, while Thalassoma virens recruited heavily to …


Establishing A Direct Role For The Bartonella Bacilliformis Invasion-Associated Locus B (Ialb) Protein In Human Erythrocyte Parasitism, Sherry A. Coleman, Michael F. Minnick Jul 2001

Establishing A Direct Role For The Bartonella Bacilliformis Invasion-Associated Locus B (Ialb) Protein In Human Erythrocyte Parasitism, Sherry A. Coleman, Michael F. Minnick

Biological Sciences Faculty Publications

The invasion-associated locus A and B genes (ialAB) of Bartonella bacilliformis were previously shown to confer an erythrocyte-invasive phenotype upon Escherichia coli, indirectly implicating their role in virulence. We report the first direct demonstration of a role for ialB as a virulence factor in B, bacilliformis. The presence of a secretory signal sequence and amino acid sequence similarity to two known outer membrane proteins involved in virulence suggested that IalB was an outer membrane protein, To develop an antiserum for protein localization, the ialB gene was cloned in frame into an expression vector with a six-histidine tag and under control …


Comparison Of A Space Shuttle Flight (Sts-78) And Bed Rest On Human Muscle Function, Scott W. Trappe, Todd A. Trappe, Gary A. Lee, Jeffrey J. Widrick, David L. Costill, Robert H. Fitts Jul 2001

Comparison Of A Space Shuttle Flight (Sts-78) And Bed Rest On Human Muscle Function, Scott W. Trappe, Todd A. Trappe, Gary A. Lee, Jeffrey J. Widrick, David L. Costill, Robert H. Fitts

Biological Sciences Faculty Research and Publications

The purpose of this investigation was to assess muscle fiber size, composition, and in vivo contractile characteristics of the calf muscle of four male crew members during a 17-day spaceflight (SF; Life and Microgravity Sciences Spacelab Shuttle Transport System-78 mission) and eight men during a 17-day bed rest (BR). The protocols and timelines of these two investigations were identical, therefore allowing for direct comparisons between SF and the BR. The subjects’ age, height, and weight were 43 +/- 2 yr, 183 +/- 4 cm, and 86 +/- 3 kg for SF and 43 +/- 2 yr, 182 +/- 3 cm, …


Temperature Effects On The Dynamics Of Aedes Albopictus (Diptera : Culicidae) Populations In The Laboratory, Barry W. Alto, Steven A. Juliano Jul 2001

Temperature Effects On The Dynamics Of Aedes Albopictus (Diptera : Culicidae) Populations In The Laboratory, Barry W. Alto, Steven A. Juliano

Faculty Publications – Biological Sciences

We investigated how constant temperatures of 22, 24, and 26 degreesC experienced across the full life cycle affected the dynamics of caged populations of Aedes albopictus (Skuse). All cages were equipped with plastic beakers that served as sites for oviposition and larval development. We measured the per capita daily mortality and emergence rates of the adults and size of adult females, and estimated the intrinsic rate of increase (r) and asymptotic density (K) for each adult population. populations at 26 degreesC had greater intrinsic rates of increase and lower asymptotic densities than populations at 22 and 24 degreesC. Populations at …


Assembly Of Reca-Like Recombinases: Distinct Roles For Mediator Proteins In Mitosis And Meiosis, Stephen L. Gasior Jul 2001

Assembly Of Reca-Like Recombinases: Distinct Roles For Mediator Proteins In Mitosis And Meiosis, Stephen L. Gasior

Biological Sciences Faculty Publications

Members of the RecA family of recombinases from bacteriophage T4, Escherichia coli, yeast, and higher eukaryotes function in recombination as higher-order oligomers assembled on tracts of single-strand DNA (ssDNA). Biochemical studies have shown that assembly of recombinase involves accessory factors. These studies have identified a class of proteins, called recombination mediator proteins, that act by promoting assembly of recombinase on ssDNA tracts that are bound by ssDNA-binding protein (ssb). In the absence of mediators, ssb inhibits recombination reactions by competing with recombinase for DNA-binding sites. Here we briefly review mediated recombinase assembly and present results of new in vivo experiments. …


Preparations For Transformation Of Drosophila Melanogaster With Green Fluorescent Protein-Tagged Dmnopp140 And Dmnopp140-Rgg By P-Element Transformation, Jennifer Mccain Jul 2001

Preparations For Transformation Of Drosophila Melanogaster With Green Fluorescent Protein-Tagged Dmnopp140 And Dmnopp140-Rgg By P-Element Transformation, Jennifer Mccain

Honors Capstones

No abstract provided.


Molecular Diversity, Structure And Domestication Of Grasses, Edward S. Buckler Iv, Jeffry M. Thornsberry, Stephen Kresovich Jun 2001

Molecular Diversity, Structure And Domestication Of Grasses, Edward S. Buckler Iv, Jeffry M. Thornsberry, Stephen Kresovich

Faculty Publications

Over the last 10,000 years, crop domestication has been the single most important human cultural development. Grasses are prominent among these crops, and provide the vast majority of the world's food. Similar traits have been selected during the domestication and breeding of these critically important grasses, and since they share a similar complement of genes, the same set of genes may have been selected. Even though the process of domestication occurred over the same 5000 to 10,000 year period, the domesticated grasses have major differences in genome structure, diversity, and life history. Molecular investigations of grass domestication have succeeded in …


Different Regulatory Mechanisms Modulate The Expression Of A Dinoflagellate Iron-Superoxide Dismutase, O. Keith Okamoto, Deborah L. Robertson, Thomas F. Fagan, J. Woodland Hastings, Pio Colepicolo Jun 2001

Different Regulatory Mechanisms Modulate The Expression Of A Dinoflagellate Iron-Superoxide Dismutase, O. Keith Okamoto, Deborah L. Robertson, Thomas F. Fagan, J. Woodland Hastings, Pio Colepicolo

Biology

Regulation of antioxidant enzymes is critical to control the levels of reactive oxygen species in cell compartments highly susceptible to oxidative stress. In this work, we studied the regulation of a chloroplastic iron superoxide dismutase (Fe-SOD) from Lingulodinium polyedrum (formerly Gonyaulax polyedra) under different physiological conditions. A cDNA-encoding Fe-SOD was isolated from this dinoflagellate, showing high sequence similarity to cyanobacterial, algal, and plant Fe-SODs. Under standard growth conditions, on a 12:12-h light-dark cycle, Lingulodinium polyedrum Fe-SOD exhibited a daily rhythm of activity and cellular abundance with the maximum occurring during the middle of the light phase. Northern analyses showed that …


G Protein Regulation Of Ion Channels And Abscisic Acid Signaling In Arabidopsis Guard Cells, Hemayet Ullah, Xi-Qing Wang, Alan Jones, Sarah Assmann Jun 2001

G Protein Regulation Of Ion Channels And Abscisic Acid Signaling In Arabidopsis Guard Cells, Hemayet Ullah, Xi-Qing Wang, Alan Jones, Sarah Assmann

Department of Biology Faculty Publications

The phytohormone abscisic acid (ABA) promotes plant water conservation by decreasing the apertures of stomatal pores in the epidermis through which water loss occurs. We found that Arabidopsis thaliana plants harboring transferred DNA insertional mutations in the sole prototypical heterotrimeric GTP-binding (G) protein alpha subunit gene, GPA1, lack both ABA inhibition of guard cell inward K(+) channels and pH-independent ABA activation of anion channels. Stomatal opening in gpa1 plants is insensitive to inhibition by ABA, and the rate of water loss from gpa1 mutants is greater than that from wild-type plants. Manipulation of G protein status in guard cells may …


Parasitism Patterns And The Size-Fecundity Relationship In The Acoustically Orienting Dipteran Parasitoid Ormia Ochracea, Gita R. Kolluru, Marlene Zuk Jun 2001

Parasitism Patterns And The Size-Fecundity Relationship In The Acoustically Orienting Dipteran Parasitoid Ormia Ochracea, Gita R. Kolluru, Marlene Zuk

Biological Sciences

Female parasitoids are expected to distribute offspring among hosts in a manner that maximizes fitness. Several theoretical and empirical studies have focussed on clutch-size patterns in hymenopteran parasitoids. In contrast, dipteran parasitoids, which differ from hymenopterans in potentially important ways, have received little attention. The phonotactic tachinid fly Ormia ochracea has been intensively studied for its effects on host crickets, and has recently been the subject of studies of its own reproductive biology. This work suggests a negative relationship between clutch size and progeny fitness (consistent with hymenopterans), but no adjustment of clutch size to host size (different from hymenopterans). …


Book Review Of "Ecology And Conservation Of Grassland Birds Of The Western Hemisphere", Eric K. Bollinger Jun 2001

Book Review Of "Ecology And Conservation Of Grassland Birds Of The Western Hemisphere", Eric K. Bollinger

Faculty Research & Creative Activity

This book review appeared in The Auk, Volume 118 No. 3 (July 2001).


Book Review Of "Ecology And Conservation Of Grassland Birds Of The Western Hemisphere", Eric Bollinger Jun 2001

Book Review Of "Ecology And Conservation Of Grassland Birds Of The Western Hemisphere", Eric Bollinger

Faculty Research & Creative Activity

This book review appeared in The Auk, Volume 118 No. 3 (July 2001).


Invasion Genetics Of New World Medflies: Testing Alternative Colonization Scenarios, Andrew J. Bohonak, Neil Davies, Francis X. Villablanca, George K. Roderick Jun 2001

Invasion Genetics Of New World Medflies: Testing Alternative Colonization Scenarios, Andrew J. Bohonak, Neil Davies, Francis X. Villablanca, George K. Roderick

Biological Sciences

The Mediterranean fruit fly (Ceratitis capitata) is an invasive agricultural pest with a wide host range and a nearly global distribution. Efforts to forgo the medfly''s spread into the United States are dependent on an understanding of population dynamics in newly established populations elsewhere. To explore the potential influence of demographic and historical parameters in six medfly populations distributed from Mexico to Peru, we created population genetic null models using Monte Carlo simulations. Null expectations for genetic differentiation (F ST) were compared with actual sequence variation from four highly polymorphic nuclear loci. Four colonization scenarios that …


Modulation Of Cell Proliferation By Heterotrimeric G Protein In Arabidopsis, Hemayet Ullah Jun 2001

Modulation Of Cell Proliferation By Heterotrimeric G Protein In Arabidopsis, Hemayet Ullah

Department of Biology Faculty Publications

The alpha subunit of a prototypical heterotrimeric GTP-binding protein (G protein), which is encoded by a single gene (GPA1) in Arabidopsis, is a modulator of plant cell proliferation. gpa1 null mutants have reduced cell division in aerial tissues throughout development. Inducible overexpression of GPA1 in Arabidopsis confers inducible ectopic cell division. GPA1 overexpression in synchronized BY-2 cells causes premature advance of the nuclear cycle and the premature appearance of a division wall. Results from loss of function and ectopic expression and activation of GPA1 indicate that this subunit is a positive modulator of cell division in plants.


Characterization Of Partially Transesterified Poly(Β-Hydroxyalkanoate)S By Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry, Broderick Eribo Jun 2001

Characterization Of Partially Transesterified Poly(Β-Hydroxyalkanoate)S By Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry, Broderick Eribo

Department of Biology Faculty Publications

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) was used for the characterization of a partially transesterified poly(beta-hydroxyalkanoate) (PHA), a polymer produced by the bacterial strain Alcaligenes eutrophus with saponified vegetable oils as the sole carbon sources. The transesterification was carried out separately under acidic and basic conditions to obtain PHA oligomers weighing <10 kDa. The intact oligomers were detected in their cationized forms, [M + Na]+ and [M + K]+, by MALDI-TOFMS. A composition analysis, using the MALDI-TOF spectra, indicated that the oligomers obtained via acid catalysis contained a methyl 3-hydroxybutyrate end group, and those obtained by base catalysis had a methyl crotonate (olefinic) end group. In addition to hydroxybutyrate (HB), the oligomers were found to contain a small percentage of hydroxyvalerate, which was independently confirmed by gas chromatography/mass spectrometry. In comparison, analysis of a commercial PHA polymer, transesterified under identical conditions, showed only the presence of HB, i.e., a pure poly(HB) homopolymer.


The Mayfly Newsletter, Peter M. Grant Jun 2001

The Mayfly Newsletter, Peter M. Grant

The Mayfly Newsletter

The Mayfly Newsletter is the official newsletter of the Permanent Committee of the International Conferences on Ephemeroptera.


High Species Diversity In Fleshy-Fruited Tropical Understory Plants, James F. Smith Jun 2001

High Species Diversity In Fleshy-Fruited Tropical Understory Plants, James F. Smith

Biology Faculty Publications and Presentations

Key innovations may increase the number of taxa in a clade that possesses the proposed innovation in comparison to its sister group that lacks the trait through either increased speciation or reduced extinction rates. Comparing sister clades across several independent lineages provides statistical support that the trait has increased species diversity. Previous studies have indicated that there may not be a relationship between biotic dispersal and higher species diversity, but only a few of these studies specified habit, habitat, or type of disperser. No previous study has specified all of the above parameters and used a phylogenetic approach. This article …


Combined, Functional Genomic-Biochemical Approach To Intermediary Metabolism: Interaction Of Acivicin, A Glutamine Amidotransferase Inhibitor, With Escherichia Coli K-12, D. R. Smulski, L. L. Huang, M. P. Mccluskey, M. J. Gladnick Reeve, Amy Cheng Vollmer, T. K. Van Dyk, R. A. Larossa Jun 2001

Combined, Functional Genomic-Biochemical Approach To Intermediary Metabolism: Interaction Of Acivicin, A Glutamine Amidotransferase Inhibitor, With Escherichia Coli K-12, D. R. Smulski, L. L. Huang, M. P. Mccluskey, M. J. Gladnick Reeve, Amy Cheng Vollmer, T. K. Van Dyk, R. A. Larossa

Biology Faculty Works

Acivicin, a modified amino acid natural product, is a glutamine analog. Thus, it might interfere with metabolism by hindering glutamine transport, formation, or usage in processes such as transamidation and translation. This molecule prevented the growth of Escherichia coli in minimal medium unless the medium was supplemented with a purine or histidine, suggesting that the HisHF enzyme, a glutamine amidotransferase, was the target of acivicin action. This enzyme, purified from E. coli, was inhibited by low concentrations of acivicin. Acivicin inhibition was overcome by the presence of three distinct genetic regions when harbored on multicopy plasmids. Comprehensive transcript profiling using …