Biology Commons^™

Effects Of Size And Temperature On Metabolic Rate, James Gillooly, James Brown, Geoffrey West, Van Savage, Eric Charnov

Biology Faculty & Staff Publications

We derive a general model, based on principles of biochemical kinetics and allometry, that characterizes the effects of temperature and body mass on metabolic rate. The model fits metabolic rates of microbes, ectotherms, endotherms (including those in hibernation), and plants in temperatures ranging from 0 to 40C. Mass - and temperature - compensated resting metabolic rates of all organisms are similar: The lowest (for unicellular organisms and plants) is separated from the highest (for endothermic vertebrates) by a factor of about 20. Temperature and body size are primary determinants of biological time and ecological roles.

Mitogen-Activated Protein Kinase Phosphorylates And Targets Inducible Camp Early Repressor To Ubiquitin-Mediated Destruction, Ghassan Yehia, Florence Schlotter, Reza Razavi, Alessandro Alessandrini, Carlos Molina

Department of Biology Faculty Scholarship and Creative Works

Inducible cAMP early repressor (ICER) is an important mediator of cAMP antiproliferative activity that acts as a putative tumor suppressor gene product. In this study, we examined the regulation of ICER protein by phosphorylation and ubiquitination in human choriocarcinoma JEG-3 and mouse pituitary AtT20 cells. We found that cAMP stabilized ICER protein by inhibiting the mitogen-activated protein kinase (MAPK) cascade. Activation of the MAPK pathway increased ICER phosphorylation. ICER phosphorylation was abrogated by inhibition of the MAPK pathway either by cAMP or directly by the MAPK inhibitor PD098059. The MAPKs extracellular signal-regulated kinases 1 and 2 physically interact with ICER …

Distinct Mechanisms Regulate Slow-Muscle Development, Michael J.F. Barresi, Joel A. D'Angelo, L. Patricia Hernández, Stephen H. Devoto

Biological Sciences: Faculty Publications

Vertebrate muscle development begins with the patterning of the paraxial mesoderm by inductive signals from midline tissues [1, 2]. Subsequent myotome growth occurs by the addition of new muscle fibers. We show that in zebrafish new slow-muscle fibers are first added at the end of the segmentation period in growth zones near the dorsal and ventral extremes of the myotome, and this muscle growth continues into larval life. In marine teleosts, this mechanism of growth has been termed stratified hyperplasia [3]. We have tested whether these added fibers require an embryonic architecture of muscle fibers to support their development and …

Biology Department Publications: 2001, Sam Lindgren

Biology Department Bibliographies

This document is a noncomprehensive list of publications made by graduate students, post-doctoral researchers, and faculty members in the Biology Department in 2001. It indexes those publications available through major databases, and serves as an archival record of the Department’s robust scholarly contributions.

Stem Morphology And Anatomy In Amaranthus L. (Amaranthaceae)—Taxonomic Significance, Mihai Costea, Darleen A. Demason

Biology Faculty Publications

The range of variation within the genus Amaranthus L. (Amaranthaceae) is described for a number of stem characters including: morphology, epidermis, primary stem vasculature and mechanism of secondary growth. The results provide new characters (phyllotaxy, complexity of leaf vascular supply and relative amount of secondary growth) that support (1) a new infrageneric classification (subgenus Amaranthus vs subgenus Albersia (Kunth)Gren. & Dodr.), and (2) the separation within the “hybridus” complex of cultivated amaranths (A. caudatus L., A. cruentus L., and A. hypochondriacus L.) from their presumed wild ancestors (A. hybridus L. subsp. quitensis (Kunth) Costea & Carretero, …

Structure Of The Rgrgs Domain Of P115rhogef, Zhe Chen, Clark D. Wells, Paul C. Sternweis, Stephen R. Sprang

Biological Sciences Faculty Publications

p115RhoGEF, a guanine nucleotide exchange factor for Rho GTPase, is also a GTPase activating protein (GAP) for G₁₂ and G₁₃ heterotrimeric Gα subunits. Near its N-terminus, p115RhoGEF contains a domain (rgRGS) with remote sequence identity to RGS (regulators of G protein signaling) domains. The rgRGS domain is necessary but not sufficient for the GAP activity of p115RhoGEF. The 1.9 Å resolution crystal structure of the rgRGS domain shows structural similarity to RGS domains but possesses a C-terminal extension that folds into a layer of helices that pack against the hydrophobic core of the domain. Mutagenesis experiments show that …

Mutations In Sid2, A Novel Gene In Saccharomyces Cerevisiae, Cause Synthetic Lethality With Sic1 Deletion And May Cause A Defect During S Phase, Matthew D. Jacobson , '97, Claudia C. Muñoz , '99, Kirstin S. Knox , '99, Beth E. Williams , '01, Lenette L. Lu , '02, Frederick Cross , '78, Elizabeth Ann Vallen

Biology Faculty Works

SIC1 encodes a nonessential B-type cyclin/CDK inhibitor that functions at the G1/S transition and the exit from mitosis. To understand more completely the regulation of these transitions, Mutations causing synthetic lethality with sic1 Delta were isolated. In this screen, we identified a novel gene, SID2, which encodes an essential protein that appear., to be required for DNA replication or repair. sid2-1 sic1 Delta strains and sid2-21 temperature-sensitive strains arrest preanaphase as large-budded cells with a single nucleus, a short spindle, and an similar to 2C DNA content. RAD9, which is necessary for the DNA damage checkpoint, is required for the …

New Vistas For Developmental Biology, Scott F. Gilbert, R. Tuan

Biology Faculty Works

No abstract provided.

Inferring And Testing Hypotheses Of Cladistic Character Dependence By Using Character Compatibility, F. Robin O’Keefe, Peter J. Wagner

Biological Sciences Faculty Research

The notion that two characters evolve independently is of interest for two reasons. First, theories of biological integration often predict that change in one character requires complementary change in another. Second, character independence is a basic assumption of most phylogenetic inference methods, and dependent characters might confound attempts at phylogenetic inference. Previously proposed tests of correlated character evolution require a model phylogeny and therefore assume that nonphylogenetic correlation has a negligible effect on initial tree construction. This paper develops “tree-free” methods for testing the independence of cladistic characters. These methods can test the character independence model as a hypothesis before …

Genomes, Gould, And Emergence, Ursula Goodenough

Biology Faculty Research

The publication of the human genome has elicited commentary to the effect that, since fewer genes were identified than anticipated, it follows that genes are less important to human biology than anticipated. The flaws in this syllogism are explained in the context of a treatise on how genomes operate and evolve and how genes function to produce embryos and brains. Most of our most cherished human traits are the result of the emergence of new properties from preexisting genetically scripted ideas, offering countless opportunities to celebrate the evolutionary process.

Precipitation And Temperature Effects On Populations Of Aedes Albopictus (Diptera : Culicidae): Implications For Range Expansion, B W. Alto, Steven A. Juliano

Faculty Publications – Biological Sciences

We investigated how temperature and precipitation regime encountered over the life cycle of Aedes albopictus (Skuse) affects populations. Caged populations of A. albopictus were maintained at 22, 26, and 30 degreesC. Cages were equipped with containers that served as sites for oviposition and larval development. All cages were assigned to one of three simulated precipitation regimes: (1) low fluctuation regime - water within the containers was allowed to evaporate to 90% of its maximum before being refilled, (2) high fluctuation regime - water was allowed to evaporate to 25% of its maximum before being refilled, and (3) drying regime - …

Functional And Structural Adaptations Of Skeletal Muscle To Microgravity, Robert H. Fitts, Danny R. Riley, Jeffrey J. Widrick

Biological Sciences Faculty Research and Publications

Our purpose is to summarize the major effects of space travel on skeletal muscle with particular emphasis on factors that alter function. The primary deleterious changes are muscle atrophy and the associated decline in peak force and power. Studies on both rats and humans demonstrate a rapid loss of cell mass with microgravity. In rats, a reduction in muscle mass of up to 37% was observed within 1 week. For both species, the antigravity soleus muscle showed greater atrophy than the fast-twitch gastrocnemius. However, in the rat, the slow type I fibers atrophied more than the fast type II fibers, …

Characterization Of Transepithelial Potential Oscillations In The Drosophila Malpighian Tubule, Edward M. Blumenthal

Biological Sciences Faculty Research and Publications

The Malpighian tubule of Drosophila melanogaster is a useful model system for studying the regulation of epithelial ion transport. In acutely isolated tubules, the transepithelial potential (TEP) undergoes large oscillations in amplitude with a period of approximately 30s. The TEP oscillations are diminished by reductions in the peritubular chloride concentration in a manner consistent with their being caused by fluctuations in chloride conductance. The oscillations are eliminated by pretreating tubules with the calcium chelator BAPTA-AM, although removal of peritubular calcium has no effect, suggesting that the oscillations are a result of either the release of calcium from intracellular stores or …

Habitat Use, Population Density, And Home Range Of Elf Owls (Micrathene Whitneyi) At Santa Ana National Wildlife Refuge, Texas, Christopher Michael Gamel, Timothy Brush

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

We collected data on the habitat use, home range size, and population density of the Elf Owl (Micrathene Whitneyi Idonea) in the Santa Ana National Wildlife refuge (SANWR) Lower Rio Grande Valley, Texas. Fourteen nocturnal surveys in 1995 and 1996 indicated that Elf Owls used chaparral habitat (92%) more than riparian woodlands(8%). Habitats used had high foliage densities(greatest density = 2.5-3.0 m) with partial canopies (x = 3.8 +_ 0.36 m [+_SE] and semi-open understories (greatest density< 1 m). Unused chaparral habitat lacked high canopy coverage and had a denser understory, while riparian woodlands had greater canopyheights (• = 5.25 m) and open understories. Home range size determined by radiotelemetry averaged1.0.5+_0.33 ha (range = 0.24-2.60, N = 9). We estimated the maximum potential population size in SANWR to be 802 Elf Owls, assuming a home range size of 1.05 ha per breeding pair and saturation of preferred habitat.

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Colectamos datos sobre el uso de habitat, tamafio del rango de hogar y densidad poblacional de Micrathene whitneyi idonea en el Refugio …

A Conserved Ubiquitin Ligase Of The Nuclear Envelope/Endoplasmic Reticulum That Functions In Both Er-Associated And Mat A2 Repressor Degradation, Rob Swanson

Biology Faculty Publications

Substrate discrimination in the ubiquitin–proteasome system is believed to be dictated by specific combinations of ubiquitin–protein ligases (E3s) and ubiquitin-conjugating enzymes (E2s). Here we identify Doa10/Ssm4 as a yeast E3 that is embedded in the endoplasmic reticulum (ER)/nuclear envelope yet can target the soluble transcription factor Mat2. Doa10 contains an unusual RING finger, which has ubiquitin-ligase activity in vitro and is essential in vivo for degradation of 2 via its Deg1 degradation signal. Doa10 functions with two E2s, Ubc6 and Ubc7, to ubiquitinate Deg1-bearing substrates, and it is also required for the degradation of at least one ER membrane protein. …

Invasive Plant Management Project, Scott J. Steinmaus

Biological Sciences

ARI Final Report - Project Number 46910.

Synaptic Heterogeneity And Stimulus-Induced Modulation Of Depression In Central Synapses, John D. Hunter, John Milton

WM Keck Science Faculty Papers

Short-term plasticity is a pervasive feature of synapses. Synapses exhibit many forms of plasticity operating over a range of time scales. We develop an optimization method that allows rapid characterization of synapses with multiple time scales of facilitation and depression. Investigation of paired neurons that are postsynaptic to the same identified interneuron in the buccal ganglion of Aplysia reveals that the responses of the two neurons differ in the magnitude of synaptic depression. Also, for single neurons, prolonged stimulation of the presynaptic neuron causes stimulus-induced increases in the early phase of synaptic depression. These observations can be described by a …

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

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

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 …

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 …

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 …

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

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 …

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 …

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

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

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

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

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 …