Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 42

Full-Text Articles in Life Sciences

Immunolocalization Of An Amino-Terminal Fragment Of Apolipoprotein E In The Pick's Disease Brain, Troy T. Rohn, Ryan J. Day, Lindsey W. Catlin, Raquel J. Brown, Alexander J. Rajic, Wayne W. Poon Dec 2013

Immunolocalization Of An Amino-Terminal Fragment Of Apolipoprotein E In The Pick's Disease Brain, Troy T. Rohn, Ryan J. Day, Lindsey W. Catlin, Raquel J. Brown, Alexander J. Rajic, Wayne W. Poon

Biology Faculty Publications and Presentations

Although the risk factor for apolipoprotein E (apoE) polymorphism in Alzheimer's disease (AD) has been well described, the role that apoE plays in other neurodegenerative diseases, including Pick's disease, is not well established. To examine a possible role of apoE in Pick's disease, an immunohistochemical analysis was performed utilizing a novel site-directed antibody that is specific for an amino-terminal fragment of apoE. Application of this antibody, termed the amino-terminal apoE cleavage fragment (nApoECF) antibody, consistently labeled Pick bodies within area CA1 of the hippocampus in 4 of the 5 cases examined. Co-localization of the nApoECF antibody with PHF-1, a general …


Abundance And Size Of Sand Crabs, Lepidopa Benedicti (Decapoda: Albuneidae), In Southern Texas, Jessica H. Murph, Zen Faulkes Dec 2013

Abundance And Size Of Sand Crabs, Lepidopa Benedicti (Decapoda: Albuneidae), In Southern Texas, Jessica H. Murph, Zen Faulkes

Biology Faculty Publications and Presentations

Albuneid sand crabs are found in sandy beaches around the world, but little is known about the basic biology of any species in the family. We sampled sand crabs, Lepidopa benedicti, for 2 years at South Padre Island, Texas, at two locations: one developed site near the town, where recreational use is high and one undeveloped site away from the town, where recreational use is lower. We hypothesized that sand crabs would be less abundant and smaller at the developed site than at the undeveloped one. Densities were highest in summer and lowest in winter but did not differ between …


Comparative Genome Analysis Of Ciprofloxacin-Resistant Pseudomonas Aeruginosa Reveals Genes Within Newly Identified High Variability Regions Associated With Drug Resistance Development, Hsun-Cheng Su, Jainab Khatun, Dona M. Kanavy, Morgan C. Giddings Nov 2013

Comparative Genome Analysis Of Ciprofloxacin-Resistant Pseudomonas Aeruginosa Reveals Genes Within Newly Identified High Variability Regions Associated With Drug Resistance Development, Hsun-Cheng Su, Jainab Khatun, Dona M. Kanavy, Morgan C. Giddings

Biology Faculty Publications and Presentations

The alarming rise of ciprofloxacin-resistant Pseudomonas aeruginosa has been reported in several clinical studies. Though the mutation of resistance genes and their role in drug resistance has been researched, the process by which the bacterium acquires high-level resistance is still not well understood. How does the genomic evolution of P. aeruginosa affect resistance development? Could the exposure of antibiotics to the bacteria enrich genomic variants that lead to the development of resistance, and if so, how are these variants distributed through the genome? To answer these questions, we performed 454 pyrosequencing and a whole genome analysis both before and after …


Taxis Toward Hydrogen Gas By Methanococcus Maripaludis, Kristen A. Brileya, James M. Connolly, Carey Downey, Robin Gerlach, Matthew W. Fields Nov 2013

Taxis Toward Hydrogen Gas By Methanococcus Maripaludis, Kristen A. Brileya, James M. Connolly, Carey Downey, Robin Gerlach, Matthew W. Fields

Biology Faculty Publications and Presentations

Knowledge of taxis (directed swimming) in the Archaea is currently expanding through identification of novel receptors, effectors, and proteins involved in signal transduction to the flagellar motor. Although the ability for biological cells to sense and swim toward hydrogen gas has been hypothesized for many years, this capacity has yet to be observed and demonstrated. Here we show that the average swimming velocity increases in the direction of a source of hydrogen gas for the methanogen, Methanococcus maripaludis using a capillary assay with anoxic gas-phase control and time-lapse microscopy. The results indicate that a methanogen couples motility to hydrogen concentration …


Effect Of Mycorrhizal Colonization And Light Limitation On Growth And Reproduction Of Lima Bean (Phaseolus Lunatus L.), Daniel J. Ballhorn, Jess A. Millar Nov 2013

Effect Of Mycorrhizal Colonization And Light Limitation On Growth And Reproduction Of Lima Bean (Phaseolus Lunatus L.), Daniel J. Ballhorn, Jess A. Millar

Biology Faculty Publications and Presentations

Plants can respond with sink stimulation of photosynthesis when colonized with fungal or bacterial root symbionts, compensating costs of carbohydrate allocation to the microbes. However, constraints may arise under light limitation when plants cannot extensively increase photosynthesis. We hypothesize that under such conditions the costs for maintaining the symbiosis outweigh the benefits, ultimately turning the mutualist microbes into parasites, resulting in reduced plant growth and reproduction.

Using lima bean (Phaseolus lunatus) as experimental plant, we applied two levels of light (full light, 75% shading) and microbial inoculation (sterile soil, mycorrhizal fungi) and quantified both vegetative and generative plant …


Protargol Synthesis: An In-House Protocol, Xuming Pan, William A. Bourland, Weibo Song Nov 2013

Protargol Synthesis: An In-House Protocol, Xuming Pan, William A. Bourland, Weibo Song

Biology Faculty Publications and Presentations

The protargol staining method has proved to be indispensable for revealing the cellular structures of a variety of protozoa, especially the flagellates and ciliates. Protargol provides permanent stains of a variety of cellular structures: nuclei, extrusomes, basal bodies, and microfilamentous constituents of cells. Together with the older silver nitrate methods, protargol impregnations have provided the basis for the detailed descriptions of nearly all ciliates to date. The performance of commercially available preparations has varied widely. Recently, suppliers have stopped stocking the effective forms of protargol resulting in a worldwide shortage. Thus, it has become necessary for protistologists to explore on-site …


Reversible Inactivation And Desiccation Tolerance Of Silicified Viruses, James R. Laidler, Jessica A. Shugart, Sherry L. Cady, Keith S. Bahjat, Kenneth M. Stedman Oct 2013

Reversible Inactivation And Desiccation Tolerance Of Silicified Viruses, James R. Laidler, Jessica A. Shugart, Sherry L. Cady, Keith S. Bahjat, Kenneth M. Stedman

Biology Faculty Publications and Presentations

Long-distance host-independent virus dispersal is poorly understood, especially for viruses found in isolated ecosystems. To
demonstrate a possible dispersal mechanism, we show that bacteriophage T4, archaeal virus Sulfolobus spindle-shaped virus Kamchatka, and vaccinia virus are reversibly inactivated by mineralization in silica under conditions similar to volcanic hot
springs. In contrast, bacteriophage PRD1 is not silicified. Moreover, silicification provides viruses with remarkable desiccation
resistance, which could allow extensive aerial dispersal.


Avoidance Of Apoptosis In Embryonic Cells Of The Annual Killifish Austrofundulus Limnaeus Exposed To Anoxia, Camie Lynn Meller, Jason E. Podrabsky Sep 2013

Avoidance Of Apoptosis In Embryonic Cells Of The Annual Killifish Austrofundulus Limnaeus Exposed To Anoxia, Camie Lynn Meller, Jason E. Podrabsky

Biology Faculty Publications and Presentations

Embryos of the annual killifish Austrofundulus limnaeus have unequalled ability among vertebrates to survive long-term anoxia. Surprisingly, these embryos can survive for months in anoxia despite a large-scale decrease in ATP levels during the initial hours of anoxic exposure. These conditions are known to trigger apoptotic cell death in mammalian cells as a result of ischemia or anoxia. Anoxia-induced induction of apoptosis was investigated in four developmental stages of A. limnaeus that differ in their tolerance of anoxia, and thus may respond to anoxia uniquely. Exposure to staurosporine was used to determine if A. limnaeus cells were competent …


Plasticity Regulators Modulate Specific Root Traits In Discrete Nitrogen Environments, Miriam L. Gifford, Joshua A. Banta, Manpreet S. Katari, Jo Hulsmans, Lisa Chen, Daniela Ristova, Daniel Tranchina, Michael D. Purugganan, Gloria M. Coruzzi, Kenneth D. Birnbaum Sep 2013

Plasticity Regulators Modulate Specific Root Traits In Discrete Nitrogen Environments, Miriam L. Gifford, Joshua A. Banta, Manpreet S. Katari, Jo Hulsmans, Lisa Chen, Daniela Ristova, Daniel Tranchina, Michael D. Purugganan, Gloria M. Coruzzi, Kenneth D. Birnbaum

Biology Faculty Publications and Presentations

Plant development is remarkably plastic but how precisely can the plant customize its form to specific environments? When the plant adjusts its development to different environments, related traits can change in a coordinated fashion, such that two traits co-vary across many genotypes. Alternatively, traits can vary independently, such that a change in one trait has little predictive value for the change in a second trait. To characterize such "tunability" in developmental plasticity, we carried out a detailed phenotypic characterization of complex root traits among 96 accessions of the model Arabidopsis thaliana in two nitrogen environments. The results revealed a surprising …


Getting To Evo-Devo: Concepts And Challenges For Students Learning Evolutionary Developmental Biology, Anna Hiatt, Gregory K. Davis, Caleb Trujillo, Mark Terry, Donald P. French, Rebecca M. Price, Kathryn E. Perez, Diane Ebert-May Sep 2013

Getting To Evo-Devo: Concepts And Challenges For Students Learning Evolutionary Developmental Biology, Anna Hiatt, Gregory K. Davis, Caleb Trujillo, Mark Terry, Donald P. French, Rebecca M. Price, Kathryn E. Perez, Diane Ebert-May

Biology Faculty Publications and Presentations

In this study we used surveys of evo-devo experts to identify the core concepts of evo-devo and outline an underlying conceptual framework. We also use interviews and surveys of conceptual difficulties with these concepts.

To examine how well biology majors have achieved the necessary foundation in evolution, numerous studies have examined how students learn natural selection. However, no studies to date have examined how students learn developmental aspects of evolution (evo-devo). Although evo-devo plays an increasing role in undergraduate biology curricula, we find that instruction often addresses development cursorily, with most of the treatment embedded within instruction on evolution. Based …


Serdemetan Antagonizes The Mdm2-Hif1Α Axis Leading To Decreased Levels Of Glycolytic Enzymes, Allan R. Albig Sep 2013

Serdemetan Antagonizes The Mdm2-Hif1Α Axis Leading To Decreased Levels Of Glycolytic Enzymes, Allan R. Albig

Biology Faculty Publications and Presentations

Serdemetan (JNJ-26854165), an antagonist to Mdm2, was anticipated to promote the activation of p53. While regulation of p53 by Mdm2 is important, Mdm2 also regulates numerous proteins involved in diverse cellular functions. We investigated if Serdemetan would alter the Mdm2-HIF1α axis and affect cell survival in human glioblastoma cells independently of p53. Treatment of cells with Serdemetan under hypoxia resulted in a decrease in HIF1α levels. HIF1α downstream targets, VEGF and the glycolytic enzymes (enolase, phosphoglycerate kinase1/2, and glucose transporter 1), were all decreased in response to Serdemetan. The involvement of Mdm2 in regulating gene expression of glycolytic enzymes raises …


Autism As The Early Closure Of A Neuroplastic Critical Period Normally Seen In Adolescence, Julia Marie Berger, Troy T. Rohn, Julia Thom Oxford Aug 2013

Autism As The Early Closure Of A Neuroplastic Critical Period Normally Seen In Adolescence, Julia Marie Berger, Troy T. Rohn, Julia Thom Oxford

Biology Faculty Publications and Presentations

The most severe cases of autism are diagnosed by extreme social dysfunction and other behavioral abnormalities. A number of genetic studies have been conducted to correlate behavioral phenotypes to genetic dysfunctions, but no “autism gene” has yet been discovered. In addition, environmental factors have been found to influence the development of autistic traits with high probability. This review will examine the role of a shortened period of neuroplasticity as a unifying feature of the autistic phenotype. The neuroplastic period of interest normally extends into adolescence, allowing for neural integration and the development of language and social skills. Early closure of …


Impacts Of An Ethanol-Blended Fuel Release On Groundwater And Fate Of Produced Methane: Simulation Of Field Observations, Kevin P. Feris Aug 2013

Impacts Of An Ethanol-Blended Fuel Release On Groundwater And Fate Of Produced Methane: Simulation Of Field Observations, Kevin P. Feris

Biology Faculty Publications and Presentations

[1] In a field experiment at Vandenberg Air Force Base (VAFB) designed to mimic the impact of a small-volume release of E10 (10% ethanol and 90% conventional gasoline), two plumes were created by injecting extracted groundwater spiked with benzene, toluene, and o-xylene, abbreviated BToX (no-ethanol lane) and BToX plus ethanol (with-ethanol lane) for 283 days. We developed a reactive transport model to understand processes controlling the fate of ethanol and BToX. The model was calibrated to the extensive field data set and accounted for concentrations of sulfate, iron, acetate, and methane along with …


A Framework For Understanding Noise Impacts On Wildlife: An Urgent Conservation Priority, Clinton D. Francis, Jesse R. Barber Aug 2013

A Framework For Understanding Noise Impacts On Wildlife: An Urgent Conservation Priority, Clinton D. Francis, Jesse R. Barber

Biology Faculty Publications and Presentations

Anthropogenic noise is an important environmental stressor that is rapidly gaining attention among biologists, resource managers, and policy makers. Here we review a substantial literature detailing the impacts of noise on wildlife and provide a conceptual framework to guide future research. We discuss how several likely impacts of noise exposure have yet to be rigorously studied and outline how behavioral responses to noise are linked to the nature of the noise stimulus. Chronic and frequent noise interferes with animals’ abilities to detect important sounds, whereas intermittent and unpredictable noise is often perceived as a threat. Importantly, these effects can lead …


Cross-Species Array Comparative Genomic Hybridization Identifies Novel Oncogenic Events In Zebrafish And Human Embryonal Rhabdomyosarcoma, Eleanor Y. Chen, Kimberly P. Dobrinski, Kim H. Brown, Ryan Clagg, Elena Edelman, Myron S. Ignatius, Jin Yun Helen Chen, Jillian Brockmann, G. Petur Nielsen, Sridhar Ramaswamy, Charles Keller, Charles Lee, David M. Langenau Aug 2013

Cross-Species Array Comparative Genomic Hybridization Identifies Novel Oncogenic Events In Zebrafish And Human Embryonal Rhabdomyosarcoma, Eleanor Y. Chen, Kimberly P. Dobrinski, Kim H. Brown, Ryan Clagg, Elena Edelman, Myron S. Ignatius, Jin Yun Helen Chen, Jillian Brockmann, G. Petur Nielsen, Sridhar Ramaswamy, Charles Keller, Charles Lee, David M. Langenau

Biology Faculty Publications and Presentations

Human cancer genomes are highly complex, making it challenging to identify specific drivers of cancer growth, progression, and tumor maintenance. To bypass this obstacle, we have applied array comparative genomic hybridization (array CGH) to zebrafish embryonal rhabdomyosaroma (ERMS) and utilized cross-species comparison to rapidly identify genomic copy number aberrations and novel candidate oncogenes in human disease. Zebrafish ERMS contain small, focal regions of low-copy amplification. These same regions were commonly amplified in human disease. For example, 16 of 19 chromosomal gains identified in zebrafish ERMS also exhibited focal, low-copy gains in human disease. Genes found in amplified genomic regions were …


Local Recruitment And Natal Dispersal Distances Of American Kestrels, Karen Steenhof, Julie A. Heath Aug 2013

Local Recruitment And Natal Dispersal Distances Of American Kestrels, Karen Steenhof, Julie A. Heath

Biology Faculty Publications and Presentations

Variation in recruitment patterns and dispersal behavior can have important consequences for population viability, genetic structure, and rates of evolutionary change. From 1992 to 2006 we studied a marked population of American Kestrels (Falco sparverius) nesting in boxes in southwestern Idaho to identify factors that affect local recruitment and natal dispersal distances. A low proportion (4%) of locally produced kestrels (n = 2180) returned to nest in study area boxes. Offspring of locally produced individuals were 3.1 times more likely to return than offspring of parents that did not hatch in study area boxes and, independent of …


Proteolytic Cleavage Of Apolipoprotein E4 As The Keystone For The Heightened Risk Associated With Alzheimer’S Disease, Troy T. Rohn Jul 2013

Proteolytic Cleavage Of Apolipoprotein E4 As The Keystone For The Heightened Risk Associated With Alzheimer’S Disease, Troy T. Rohn

Biology Faculty Publications and Presentations

Alzheimer’s disease (AD) is a progressive neurodegenerative disease characterized by microscopic lesions consisting of beta-amyloid plaques and neurofibrillary tangles (NFTs). The majority of cases are defined as sporadic and are likely caused by a combination of both genetic and environmental factors. Of the genetic risk factors identified, the 34 kDa protein, apolipoprotein (apo) E4, is of significant importance as APOE4 carriers account for 65%–80% of all AD cases. Although apoE4 plays a normal role in lipoprotein transport, how it contributes to AD pathogenesis is currently unknown. One potential mechanism by which apoE4 contributes to disease risk is its propensity to …


Safeguarding Forensic Dna Reference Samples With Nullomer Barcodes, Jayita Goswami, Michael C. Davis, Tim Andersen, Abdelkrim Alileche, Greg Hampikian Jul 2013

Safeguarding Forensic Dna Reference Samples With Nullomer Barcodes, Jayita Goswami, Michael C. Davis, Tim Andersen, Abdelkrim Alileche, Greg Hampikian

Biology Faculty Publications and Presentations

Unintended transfer of biological material containing DNA is a concern to all laboratories conducting PCR analysis. While forensic laboratories have protocols in place to reduce the possibility of contaminating casework samples, there is no way to detect when a reference sample is mislabeled as evidence, or contaminates a forensic sample. Thus there is public concern regarding the safeguarding of DNA submitted to crime labs. We demonstrate a method of introducing an internal amplification control to reference samples, in the form of a nullomer barcode which is based upon sequences absent or rare from publically accessible DNA databases. The detection of …


Increase In Acc Oxidase Levels And Activities During Paradormancy Release Of Leafy Spurge (Euphorbia Esula) Buds, Wun S. Chao, Marcelo Serpe, Jeffrey C. Suttle, Ying Jia Jul 2013

Increase In Acc Oxidase Levels And Activities During Paradormancy Release Of Leafy Spurge (Euphorbia Esula) Buds, Wun S. Chao, Marcelo Serpe, Jeffrey C. Suttle, Ying Jia

Biology Faculty Publications and Presentations

The plant hormone ethylene is known to affect various developmental processes including dormancy and growth. Yet, little information is available about the role of ethylene during paradormancy release in underground adventitious buds of leafy spurge. In this study, we examined changes in ethylene evolution and the ethylene biosynthetic enzyme ACC oxidase following paradormancy release (growth induction). Our results did not show an obvious increase in ethylene during bud growth. However, when buds were incubated with 1 mM ACC, ethylene levels were higher in growing than non-growing buds, suggesting that the levels of ACC oxidase increased in growing buds. Real-time qPCR …


Residential Edges As Ecological Traps: Postfledgling Survival Of A Ground-Nesting Passerine In A Forested Urban Park, Amy A. Shipley, Michael T. Murphy, Adam H. Elzinga Jul 2013

Residential Edges As Ecological Traps: Postfledgling Survival Of A Ground-Nesting Passerine In A Forested Urban Park, Amy A. Shipley, Michael T. Murphy, Adam H. Elzinga

Biology Faculty Publications and Presentations

Substantial offspring mortality can occur during the postfledging period of birds, but few postfledging survival studies have been conducted within the context of habitat suitability. We conducted a 2-year radiotelemetry study of Spotted Towhee (Pipilo maculatus) reproductive success and fledgling survival in a 24-ha forested park in a residential area of Lake Oswego, Oregon. In corroboration of previous research on this species, we found (1) that Spotted Towhees nested closer to the edge between the park and residential neighborhoods than expected by chance, and (2) that pairs nesting near edges produced the largest and most offspring. However, fates were reversed …


Examining New Phylogenetic Markers To Uncover The Evolutionary History Of Early-Diverging Fungi: Comparing Mcm7, Tsr1 And Rrna Genes For Single- And Multi-Gene Analyses Of The Kickxellomycotina, Eric D. Tretter, E. M. Johnson, Yan Wang, Prasanna Kandel, Merlin M. White Jun 2013

Examining New Phylogenetic Markers To Uncover The Evolutionary History Of Early-Diverging Fungi: Comparing Mcm7, Tsr1 And Rrna Genes For Single- And Multi-Gene Analyses Of The Kickxellomycotina, Eric D. Tretter, E. M. Johnson, Yan Wang, Prasanna Kandel, Merlin M. White

Biology Faculty Publications and Presentations

The recently recognised protein-coding genes MCM7 and TSR1 have shown significant promise for phylogenetic resolution within the Ascomycota and Basidiomycota, but have remained unexamined within other fungal groups (except for Mucorales). We designed and tested primers to amplify these genes across early-diverging fungal clades, with emphasis on the Kickxellomycotina, zygomycetous fungi with characteristic flared septal walls forming pores with lenticular plugs. Phylogenetic tree resolution and congruence with MCM7 and TSR1 were compared against those inferred with nuclear small (SSU) and large subunit (LSU) rRNA genes. We also combined MCM7 and TSR1 data with the rDNA data to …


Evolution Of A Higher Intracellular Oxidizing Environment In Caenorhabditis Elegans Under Relaxed Selection, Joanna Joyner-Matos, Kiley A. Hicks, Dustin Cousins, Michelle Keller, Dee R. Denver, Charles F. Baer, Suzanne Estes Jun 2013

Evolution Of A Higher Intracellular Oxidizing Environment In Caenorhabditis Elegans Under Relaxed Selection, Joanna Joyner-Matos, Kiley A. Hicks, Dustin Cousins, Michelle Keller, Dee R. Denver, Charles F. Baer, Suzanne Estes

Biology Faculty Publications and Presentations

We explored the relationship between relaxed selection, oxidative stress, and spontaneous mutation in a set of mutationaccumulation (MA) lines of the nematode Caenorhabditis elegans and in their common ancestor. We measured steady-state levels of free radicals and oxidatively damaged guanosine nucleosides in the somatic tissues of five MA lines for which nuclear genome base substitution and GC-TA transversion frequencies are known. The two markers of oxidative stress are highly correlated and are elevated in the MA lines relative to the ancestor; point estimates of the per-generation rate of mutational decay (DM) of these measures of oxidative stress are similar to …


Biochemical, Nutrient And Inhibitory Characteristics Of Streptomyces Cultured From A Hypersaline Estuary, The Laguna Madre (Texas), Luis E. Espinoza, Anita L. Davelos Baines, Kristine L. Lowe May 2013

Biochemical, Nutrient And Inhibitory Characteristics Of Streptomyces Cultured From A Hypersaline Estuary, The Laguna Madre (Texas), Luis E. Espinoza, Anita L. Davelos Baines, Kristine L. Lowe

Biology Faculty Publications and Presentations

Streptomyces are common soil bacteria that produce secondary metabolites, including several antibiotics; however, the characteristics of marine Streptomyces are largely unknown. Sediment samples were taken from 3 sites in the Laguna Madre to isolate marine Streptomyces. Sediment was diluted, spread onto synthetic seawater media to estimate the total bacterial density of the samples and spread onto starch casein agar to isolate Streptomyces. Isolated Streptomyces were tested for salinity tolerance and optimal growth pH. Isolates were assayed using API 20E® test strips and BIOLOG™ plates to construct biochemical profiles and assess nutrient utilization abilities of the bacteria, respectively. Individual Streptomyces were …


Bromus Tectorum Litter Alters Photosynthetic Characteristics Of Biological Soil Crusts From A Semiarid Shrubland, Marcelo D. Serpe, Eric Roberts, David J. Eldridge, Roger Rosentreter May 2013

Bromus Tectorum Litter Alters Photosynthetic Characteristics Of Biological Soil Crusts From A Semiarid Shrubland, Marcelo D. Serpe, Eric Roberts, David J. Eldridge, Roger Rosentreter

Biology Faculty Publications and Presentations

Invasion by the exotic annual grass Bromus tectorum has increased the cover and connectivity of fine litter in the sagebrush steppes of western North America. This litter tends to cover biological soil crusts, which could affect their metabolism and growth. To investigate this possible phenomenon, biological soil crusts dominated by either the moss Bryum argenteum or the lichen Diploschistes muscorum were covered with B.tectorum litter (litter treatment) or left uncovered (control treatment) and exposed to natural field conditions. After periods of five and ten months, we removed the litter and compared the photosynthetic performance of biological soil crusts …


The Extracellular Polysaccharide Pel Makes The Attachment Of P. Aeruginosa To Surfaces Symmetric And Short-Ranged, Benjamin J. Cooley, Travis W. Thatcher, Sara M. Hashmi, Guillaume L'Her, Daniel A. Hurwitz, Daniele Provenzano, Ahmed Touhami, Vernita D. Gordon Apr 2013

The Extracellular Polysaccharide Pel Makes The Attachment Of P. Aeruginosa To Surfaces Symmetric And Short-Ranged, Benjamin J. Cooley, Travis W. Thatcher, Sara M. Hashmi, Guillaume L'Her, Daniel A. Hurwitz, Daniele Provenzano, Ahmed Touhami, Vernita D. Gordon

Biology Faculty Publications and Presentations

Biofilms are surface-mounted, multicellular communities of microbes. Biofilms are often associated with chronic infections that resist treatment, evade the immune system, and damage host tissue. An essential characteristic of the biofilm state is that constituent organisms are bound in a polymeric matrix. This matrix gives the system spatial structure and clusters bacteria near each other, facilitating intercellular interactions. The Pseudomonas aeruginosa strain PAO1 is widely studied as a model biofilm-forming organism. The polymeric matrix of PAO1 biofilms is dominated by two bacteria-produced extracellular polymers, Pel and Psl. We use a combination of optical and atomic force microscopy to examine the …


Human Disturbance And Stage-Specific Habitat Requirements Influence Snowy Plover Site Occupancy During The Breeding Season, Alyson F. Webber, Julie A. Heath, Richard A. Fischer Apr 2013

Human Disturbance And Stage-Specific Habitat Requirements Influence Snowy Plover Site Occupancy During The Breeding Season, Alyson F. Webber, Julie A. Heath, Richard A. Fischer

Biology Faculty Publications and Presentations

Habitat use has important consequences for avian reproductive success and survival. In coastal areas with recreational activity, human disturbance may limit use of otherwise suitable habitat. Snowy plovers Charadrius nivosus have a patchy breeding distribution along the coastal areas on the Florida Panhandle, USA. Our goal was to determine the relative effects of seasonal human disturbance and habitat requirements on snowy plover habitat use. We surveyed 303 sites for snowy plovers, human disturbance, and habitat features between January and July 2009 and 2010. We made multiple visits during three different sampling periods that corresponded to snowy plover breeding: pre-breeding, incubation, …


Migration Timing And Wintering Areas Of Three Species Of Flycatchers (Tyrannus) Breeding In The Great Plains Of North America, Alex E. Jahn, Victor R. Cueto, James W. Fox, Michael S. Husak, Daniel H. Kim, Diane V. Landoll, Jesús Pinto Ledezma, Heather K. Lepage, Douglas J. Levey, Michael T. Murphy, Rosalind B. Renfrew Apr 2013

Migration Timing And Wintering Areas Of Three Species Of Flycatchers (Tyrannus) Breeding In The Great Plains Of North America, Alex E. Jahn, Victor R. Cueto, James W. Fox, Michael S. Husak, Daniel H. Kim, Diane V. Landoll, Jesús Pinto Ledezma, Heather K. Lepage, Douglas J. Levey, Michael T. Murphy, Rosalind B. Renfrew

Biology Faculty Publications and Presentations

Descriptions of intra- and interspecific variation in migratory patterns of closely related species are rare yet valuable because they can help assess how differences in ecology and life-history strategies drive the evolution of migration. We report data on timing and location of migration routes and wintering areas, and on migratory speed and phenology, of Eastern Kingbirds (Tyrannus tyrannus) from Nebraska and Oklahoma and of Western Kingbirds (T. verticalis) and Scissor-tailed Flycatchers (T. forficatus) from Oklahoma. Eastern Kingbirds primarily departed the breeding site in September, migrating to the Amazon Basin (Bolivia and Brazil), >6,400 km …


Insights Into Archaeal Evolution And Symbiosis From The Genomes Of A Nanoarchaeon And Its Inferred Crenarchaeal Host From Obsidian Pool, Yellowstone National Park, Mircea Podar, Kira S. Makarova, David E. Graham, Yuri L. Wolf, Eugene V. Koonin, Anna-Louise Reysenbach Apr 2013

Insights Into Archaeal Evolution And Symbiosis From The Genomes Of A Nanoarchaeon And Its Inferred Crenarchaeal Host From Obsidian Pool, Yellowstone National Park, Mircea Podar, Kira S. Makarova, David E. Graham, Yuri L. Wolf, Eugene V. Koonin, Anna-Louise Reysenbach

Biology Faculty Publications and Presentations

Background: A single cultured marine organism, Nanoarchaeum equitans, represents the Nanoarchaeota branch of symbiotic Archaea, with a highly reduced genome and unusual features such as multiple split genes.

Results: The first terrestrial hyperthermophilic member of the Nanoarchaeota was collected from Obsidian Pool, a thermal feature in Yellowstone National Park, separated by single cell isolation, and sequenced together with its putative host, a Sulfolobales archaeon. Both the new Nanoarchaeota (Nst1) and N. equitans lack most biosynthetic capabilities, and phylogenetic analysis of ribosomal RNA and protein sequences indicates that the two form a deepbranching archaeal lineage. However, the Nst1 …


A Pharm-Ecological Perspective Of Terrestrial And Aquatic Plant-Herbivore Interactions, Jennifer Sorensen Forbey, M. Denise Dearing, Elisabeth M. Gross, Colin M. Orians, Erik E. Sotka, William J. Foley Apr 2013

A Pharm-Ecological Perspective Of Terrestrial And Aquatic Plant-Herbivore Interactions, Jennifer Sorensen Forbey, M. Denise Dearing, Elisabeth M. Gross, Colin M. Orians, Erik E. Sotka, William J. Foley

Biology Faculty Publications and Presentations

We describe some recent themes in the nutritional and chemical ecology of herbivores and the importance of a broad pharmacological view of plant nutrients and chemical defenses that we integrate as “Pharm-ecology”. The central role that dose, concentration, and response to plant components (nutrients and secondary metabolites) play in herbivore foraging behavior argues for broader application of approaches derived from pharmacology to both terrestrial and aquatic plant-herbivore systems. We describe how concepts of pharmacokinetics and pharmacodynamics are used to better understand the foraging phenotype of herbivores relative to nutrient and secondary metabolites in food. Implementing these concepts into the field …


Sequencing And De Novo Transcriptome Assembly Of Brachypodium Sylvaticum (Poaceae), Samuel E. Fox, Justin Preece, Jeffrey A. Kimbrel, Gina L. Marchini, Abigail Sage, Ken Youens-Clark, Mitchell B. Cruzan, Pankaj Jaiswal Mar 2013

Sequencing And De Novo Transcriptome Assembly Of Brachypodium Sylvaticum (Poaceae), Samuel E. Fox, Justin Preece, Jeffrey A. Kimbrel, Gina L. Marchini, Abigail Sage, Ken Youens-Clark, Mitchell B. Cruzan, Pankaj Jaiswal

Biology Faculty Publications and Presentations

Premise of the study: We report the de novo assembly and characterization of the transcriptomes of Brachypodium sylvaticum (slender false-brome) accessions from native populations of Spain and Greece, and an invasive population west of Corvallis, Oregon, USA. Methods and Results: More than 350 million sequence reads from the mRNA libraries prepared from three B. sylvaticum genotypes were assembled into 120,091 (Corvallis), 104,950 (Spain), and 177,682 (Greece) transcript contigs. In comparison with the B. distachyon Bd21 reference genome and GenBank protein sequences, we estimate >90% exome coverage for B. sylvaticum . The transcripts were assigned Gene Ontology and InterPro annotations. Brachypodium …