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Articles 811 - 840 of 2711

Full-Text Articles in Biology

An Improved Competitive Inhibition Enzymatic Immunoassay Method For Tetrodotoxin Quantification, James P. Strange, Becky L. Williams, Susannah S. French Jan 2012

An Improved Competitive Inhibition Enzymatic Immunoassay Method For Tetrodotoxin Quantification, James P. Strange, Becky L. Williams, Susannah S. French

Biology Faculty Publications

Quantifying tetrodotoxin (TTX) has been a challenge in both ecological and medical research due to the cost, time and training required of most quantification techniques. Here we present a modified Competitive Inhibition Enzymatic Immunoassay for the quantification of TTX, and to aid researchers in the optimization of this technique for widespread use with a high degree of accuracy and repeatability.


Improved Ex Vivo Method For Microbiocidal Activity Across Vertebrate Species, Susannah S. French, Lorin A. Neuman-Lee Jan 2012

Improved Ex Vivo Method For Microbiocidal Activity Across Vertebrate Species, Susannah S. French, Lorin A. Neuman-Lee

Biology Faculty Publications

The field of ecoimmunology is currently undergoing rapid expansion, whereby biologists from a wide range of ecological disciplines are increasingly interested in assessing immunocompetence in their study organisms. One of the key challenges to researchers is determining what eco-immune measures to use in a given experiment. Moreover, there are limitations depending on study species, requirements for specific antibodies, and relevance of the methodology to the study organism. Here we introduce an improved ex vivo method for microbiocidal activity across vertebrate species. The utility of this assay is that it determines the ability of an organism to remove a pathogen that …


Widespread Triploidy In Western North American Aspen (Populus Tremuloides), Karen E. Mock, Colin M. Callahan, M. Nurul Islam-Faridi, John D. Shaw, Hardeep S. Rai, Stewart C. Sanderson, Carol A. Rowe, Ronald J. Rye, Michael D. Madritch, Richard S. Gardner, Paul G. Wolf Jan 2012

Widespread Triploidy In Western North American Aspen (Populus Tremuloides), Karen E. Mock, Colin M. Callahan, M. Nurul Islam-Faridi, John D. Shaw, Hardeep S. Rai, Stewart C. Sanderson, Carol A. Rowe, Ronald J. Rye, Michael D. Madritch, Richard S. Gardner, Paul G. Wolf

Biology Faculty Publications

We document high rates of triploidy in aspen (Populus tremuloides) across the western USA (up to 69% of genets), and ask whether the incidence of triploidy across the species range corresponds with latitude, glacial history (as has been documented in other species), climate, or regional variance in clone size. Using a combination of microsatellite genotyping, flow cytometry, and cytology, we demonstrate that triploidy is highest in unglaciated, drought-prone regions of North America, where the largest clone sizes have been reported for this species. While we cannot completely rule out a low incidence of undetected aneuploidy, tetraploidy or duplicated loci, our …


Methodological Tools, Ethan P. White, Xiao Xiao, J. B. Nick, Richard M. Sibly Jan 2012

Methodological Tools, Ethan P. White, Xiao Xiao, J. B. Nick, Richard M. Sibly

Biology Faculty Publications

Methodological approaches for comparing metabolic theory predictions to empirical data fall into two general categories: 1) determining if the general functional form of a relationship predicted by the theory is valid; and 2) determining whether the observed values of the parameters match the specific quantitative predictions made by the theory. Both of these categories of analysis rely on being able to accurately determine the best fitting form of a model with the same general functional form as that of MTE, so we will begin by discussing how this has typically been done using OLS regression on appropriately transformed data. Potential …


Investigating Human Impact In The Environment With Faded Scaffolded Inquiry Supported By Technologies, D. T. Longhurst, M. Longhurst, A. M. Duffy, Paul G. Wolf Jan 2012

Investigating Human Impact In The Environment With Faded Scaffolded Inquiry Supported By Technologies, D. T. Longhurst, M. Longhurst, A. M. Duffy, Paul G. Wolf

Biology Faculty Publications

Teaching science as inquiry is advocated in all national science education documents and by leading science and science teaching organizations. In addition to teaching science as inquiry, we recognize that learning experiences need to connect to students’ lives. This article details how we use a sequence of faded scaffolded inquiry supported by technologies to engage students meaningfully in science connected to their lives and schoolyards. In this approach, more teacher guidance is provided earlier in the inquiry experiences before this is faded later in the sequence, as students are better prepared to complete successful inquiries. The sequence of inquiry experiences …


Survey Of Erwinia Amylovora, Causal Agent Of Fire Blight, From Apple And Pear Orchards In Utah For Streptomycin Resistance, Christine Dhiman Jan 2012

Survey Of Erwinia Amylovora, Causal Agent Of Fire Blight, From Apple And Pear Orchards In Utah For Streptomycin Resistance, Christine Dhiman

Browse All Undergraduate research

Fire blight caused by the bacterium Erwinia amylovora results in millions of dollar in losses worldwide. It is the most important disease problem for apple and pear growers in Utah. Currently the only effective management strategy is application of the antibiotic streptomycin. In 2006, resistant isolates were detected in an apple orchard in Utah County. To determine the distribution of resistant isolates, samples collected in 2006, 2007, 2010 and 2011 from orchards across Utah were tested for resistance to streptomycin. Isolates were screened at 0, 100 and 1000ppm of streptomycin. Bacteria were spread on LB agar. A hole was punched …


Relative Importance Of Environmental Variables For Spawning Cues And Tributary Use By An Adfluvial Lake Sucker, Brian A. Hines Dec 2011

Relative Importance Of Environmental Variables For Spawning Cues And Tributary Use By An Adfluvial Lake Sucker, Brian A. Hines

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The endangered June sucker (Chasmistes liorus mictus), which is only found in Utah Lake, UT, historically spawned in all streams flowing into the lake, but due to human-caused changes their spawning is restricted to the Provo River. The purpose of this study was to gain a better understanding of the spawning and early life-history of the
June sucker for recovery purposes. My specific objectives were to determine:

  1. what environmental factors attract or deter June suckers to certain Utah Lake tributaries for spawning,
  2. what cues June suckers to migrate upstream to spawn,
  3. if June suckers use more than one …


Effect Of Voluntary Exercise And Diet On The Unfolded Protein Response In The Brain Of Mice, Yu Ho Kim Dec 2011

Effect Of Voluntary Exercise And Diet On The Unfolded Protein Response In The Brain Of Mice, Yu Ho Kim

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The medical costs for many chronic diseases are increasing dramatically and placing a major financial burden on nations and individuals in both developed and developing countries. A number of chronic diseases, such as obesity, type 2 diabetes and some neurodegenerative diseases are all attenuated by a history of physical activity suggesting that they may be interconnected in some way. It has been suggested that cellular stress is a major factor promoting these chronic diseases.

Cellular stress occurs in a specific compartment within the cell, the endoplasmic reticulum, whose normal function is in the synthesis and folding of proteins into the …


The Biogeography Of Marbled Godwit (Limosa Fedoa) Populations In North America, Bridget E. Olson Dec 2011

The Biogeography Of Marbled Godwit (Limosa Fedoa) Populations In North America, Bridget E. Olson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The mission of the U.S. Fish and Wildlife Service (USFWS) is working with others to conserve, protect, and enhance fish, wildlife, plants, and their habitats for the continuing benefit of the American people. Toward fulfillment of that mission, a priority of the USFWS is conservation and management of migratory birds. Effective conservation actions to ensure the continued existence of a species on the landscape cannot be designed without first understanding basic life history characteristics of a species. It is common in the case of migratory birds, that we lack understanding of some of their elemental biological traits.

The Marbled Godwit, …


Linking Fruit Traits To Variation In Predispersal Vertebrate Seed Predation, Insect Seed Predation, And Pathogen Attack, Noelle G. Beckman, Helene C. Muller-Landau Nov 2011

Linking Fruit Traits To Variation In Predispersal Vertebrate Seed Predation, Insect Seed Predation, And Pathogen Attack, Noelle G. Beckman, Helene C. Muller-Landau

Biology Faculty Publications

The importance of vertebrates, invertebrates, and pathogens for plant communities has long been recognized, but their absolute and relative importance in early recruitment of multiple coexisting tropical plant species has not been quantified. Further, little is known about the relationship of fruit traits to seed mortality due to natural enemies in tropical plants. To investigate the influences of vertebrates, invertebrates, and pathogens on reproduction of seven canopy plant species varying in fruit traits, we quantified reductions in fruit development and seed germination due to vertebrates, invertebrates, and fungal pathogens through experimental removal of these enemies using canopy exclosures, insecticide, and …


Loss-Of-Function Of Constitutive Expresser Of Pathogenesis Related Genes5 Affects Potassium Homeostasis In Arabidopsis Thaliana, Monica Borghi, Ana Rus, David E. Salt Oct 2011

Loss-Of-Function Of Constitutive Expresser Of Pathogenesis Related Genes5 Affects Potassium Homeostasis In Arabidopsis Thaliana, Monica Borghi, Ana Rus, David E. Salt

Biology Faculty Publications

Here, we demonstrate that the reduction in leaf K+ observed in a mutant previously identified in an ionomic screen of fast neutron mutagenized Arabidopsis thaliana is caused by a loss-of-function allele of CPR5, which we name cpr5-3. This observation establishes low leaf K+ as a new phenotype for loss-of-function alleles of CPR5. We investigate the factors affecting this low leaf K+ in cpr5 using double mutants defective in salicylic acid (SA) and jasmonic acid (JA) signalling, and by gene expression analysis of various channels and transporters. Reciprocal grafting between cpr5 and Col-0 was used to determine the relative importance of …


The Decline And Conservation Status Of North American Bumble Bees, Jonathan B. Koch Aug 2011

The Decline And Conservation Status Of North American Bumble Bees, Jonathan B. Koch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Several reports of North American bumble bee (Bombus Latreille) decline have been documented across the continent, but no study has fully assessed the geographic scope of decline. In this study I discuss the importance of Natural History Collections (NHC) in estimating historic bumble bee distributions and abundances, as well as in informing current surveys. To estimate changes in distribution and relative abundance I compare historic data assembled from a >73,000 specimen database with a contemporary 3-year survey of North American bumble bees across 382 locations in the contiguous U.S.A. Based on my results, four historically abundant bumble bees, B. …


The High Cost Of Cheap Coal; Why Can't We Move To Renewable Energy, Cameron Dale Bartlett May 2011

The High Cost Of Cheap Coal; Why Can't We Move To Renewable Energy, Cameron Dale Bartlett

Undergraduate Honors Capstone Projects

This article addresses the historic and current use of coal as the main source of electric power throughout the United States. Coal powered power plants remain an important part of the history and industrialization of the United States, even though there are many detrimental health and environmental impacts associated with its use. A slowly growing trend has been emerging with research on and use of renewable energy to replace fossil fuels, such as coal. Greater public awareness and involvement will help drive the slowly emerging use of renewable energy. This article looks at the current barriers that are prohibiting the …


The Role Of Phosphoinositide Signaling In Breast Cancer Metastasis Suppressor 1-Mediated Metastasis Suppression Of Human Breast Carcinoma Cells, Sitaram Harihar May 2011

The Role Of Phosphoinositide Signaling In Breast Cancer Metastasis Suppressor 1-Mediated Metastasis Suppression Of Human Breast Carcinoma Cells, Sitaram Harihar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Breast cancer is the most common non-skin cancer in women and the second most common cause of cancer-related death in U.S. women. Despite numerous advances in treatment strategies against breast cancer, the presence of undetected distant metastasis of the primary tumor remains the main cause of mortality. Current screening and detection methods such as mammograms are simply not sensitive enough to detect formation of metastasis. Further, currently available therapies against metastatic breast cancer do not provide a complete cure for the disease. Thus, understanding the biology and molecular factors involved in cancer metastasis will help aid in preventing the onset …


Design Of A BiobrickTm Compatible Gene Expression System For Rhodobacter Sphaeroides, Junling Huo May 2011

Design Of A BiobrickTm Compatible Gene Expression System For Rhodobacter Sphaeroides, Junling Huo

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The concept of introducing engineering principles of abstraction and standardization into synthetic biology has received increasing attention in the past several years and continues to be in the forefront of synthetic biology. One direction being pursued by synthetic biologists is creation of modular biological parts (BioBrickTM) that can be readily synthesized and mixed together in different combinations. However, most standard BioBrickTM parts in the Registry were designed for E. coli, although synthesis of specific BioBrickTM parts for other bacteria, such as for yeast and cyanobacteria, have begun. Besides, at the present time, there are only …


Characterization And Application Of Dynamic In Vitro Models Of Human Airway, Hemangkumar J. Patel May 2011

Characterization And Application Of Dynamic In Vitro Models Of Human Airway, Hemangkumar J. Patel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In recent years, respiratory diseases have emerged as a leading cause of mortality across the globe. In the United States alone respiratory diseases are the fourth leading cause of deaths annually. Moreover, with the rapid increase of industrialization and urbanization, the occurrences of respiratory diseases are expected to remain high with strong chances of increasing in the future. To ameliorate the epidemic of respiratory disease, it is first important to understand its underlying mechanisms.

Respiratory research studies in animals have elucidated the chronological order of the pathological events and systemic responses inside the lung, but understanding the response of individual …


A Study On The Applications And Toxicity Assessments Of Carbon Nanotubes In Tissue Engineering, Rena Baktur May 2011

A Study On The Applications And Toxicity Assessments Of Carbon Nanotubes In Tissue Engineering, Rena Baktur

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Carbon nanotubes (CNTs) are one of the most popular nanomaterials. There has been increasing interest in the development and applications of carbon nanotubes due to their huge potential in industrial and medical applications. Recent applications of carbon nanotubes include development of scaffolds and drug delivery systems. Despite rapidly emerging applications of CNTs, little is known about the impact of CNTs on cellular processes, especially mesenchymal stem cell (MSC)'s differentiation. Also, the effects of nanoparticle exposure under different conditions on cellular responses have not been well characterized yet.

To characterize the effects of CNTs on creating nanoscale scaffolds for tissue engineering, …


Is Wildlife Going To The Dogs? Impacts Of Feral And Free-Roaming Dogs On Wildlife Populations, Julie K. Young, Kirk A. Olson, Richard P. Reading, Sukh Amgalanbaatar, Joel Berger Feb 2011

Is Wildlife Going To The Dogs? Impacts Of Feral And Free-Roaming Dogs On Wildlife Populations, Julie K. Young, Kirk A. Olson, Richard P. Reading, Sukh Amgalanbaatar, Joel Berger

Wildland Resources Faculty Publications

In human-populated landscapes, dogs (Canis familiaris) are often the most abundant terrestrial carnivore. However, dogs can significantly disrupt or modify intact ecosystems well beyond the areas occupied by people. Few studies have directly quantified the environmental or economic effects of free-roaming and feral dogs. Here, we review wildlife-dog interactions and provide a case study that focuses on interactions documented from our research in Mongolia to underscore the need for studies designed to best determine how dogs affect native wildlife and especially imperiled populations. We suggest additional research, public awareness campaigns, and the exclusion of dogs from critical wildlife habitat. The …


Temperature Increase Effects On Sagebrush Ecosystem Forbs: Exprimental Evidence And Range Manager Perspectives, Hilary Louise Whitcomb Jan 2011

Temperature Increase Effects On Sagebrush Ecosystem Forbs: Exprimental Evidence And Range Manager Perspectives, Hilary Louise Whitcomb

Green Canyon Environmental Research Area, Logan Utah

No abstract provided.


On The Use Of Log-Transformation Vs. Nonlinear Regression For Analyzing Biological Power-Laws, Xiao Xiao, Ethan P. White, M. B. Hooten, Susan L. Durham Jan 2011

On The Use Of Log-Transformation Vs. Nonlinear Regression For Analyzing Biological Power-Laws, Xiao Xiao, Ethan P. White, M. B. Hooten, Susan L. Durham

Biology Faculty Publications

Power-law relationships are among the most well-studied functional relationships in biology. Recently the common practice of fitting power-laws using linear regression on log-transformed data (LR) has been criticized, calling into question the conclusions of hundreds of studies. It has been suggested that nonlinear regression (NLR) is preferable, but no rigorous comparison of these two methods has been conducted. Using Monte Carlo simulations we demonstrate that the error distribution determines which method performs better, with LR better characterizing data with multiplicative lognormal error and NLR better characterizing data with additive, homoscedastic, normal error. Analysis of 471 biological power-laws shows that both …


Species Compositionand Abundance Of Mammalian Communities, K. M. Thibault, S. R. Supp, M. Griffin, Ethan P. White, S.K. Morgan Ernest Jan 2011

Species Compositionand Abundance Of Mammalian Communities, K. M. Thibault, S. R. Supp, M. Griffin, Ethan P. White, S.K. Morgan Ernest

Biology Faculty Publications

Ecologists have long sought to understand the mechanisms underlying the assembly and structure of communities. Such understanding is relevant to both basic science and conservation-related issues. The macroecological approach to this problem involves asking scientific questions using a large number of communities in order to elucidate generalities in pattern and process. Such analyses are typically conducted using a substantial amount of data from a particular taxonomic group across a diversity of systems. Large community databases are available for a number of taxa, but no publicly available database exists for mammals. Given the logistical challenges of collecting such data de novo, …


Dissimilatory Nitrate Reductionpathways In An Oligotrophic Aquatic Ecosystem: Spatial And Temporal Trends, I. J. Washbourne, C. L. Crenshaw, Michelle A. Baker Jan 2011

Dissimilatory Nitrate Reductionpathways In An Oligotrophic Aquatic Ecosystem: Spatial And Temporal Trends, I. J. Washbourne, C. L. Crenshaw, Michelle A. Baker

Biology Faculty Publications

Elevated nitrate (NO3−) concentrations can cause eutrophication, which may lead to harmful algal blooms, loss of habitat and reduction in biodiversity. Denitrification, a dissimilatory process that removes NO3− mainly as dinitrogen gas (N2), is believed to be the dominant NO3− removal pathway in aquatic ecosystems. Evidence suggests that a less well-studied process, dissimilatory nitrate reduction to ammonium (DNRA), which retains nitrogen (N) in the system, may also be important under favorable conditions. Using stable isotope tracers in sealed microcosms, we measured the potential for NO3− losses due to DNRA …


Simple Structural Differences Between Coding And Noncodingdna, Kenneth J. Locey, Ethan P. White Jan 2011

Simple Structural Differences Between Coding And Noncodingdna, Kenneth J. Locey, Ethan P. White

Biology Faculty Publications

Background

The study of large-scale genome structure has revealed patterns suggesting the influence of evolutionary constraints on genome evolution. However, the results of these studies can be difficult to interpret due to the conceptual complexity of the analyses. This makes it difficult to understand how observed statistical patterns relate to the physical distribution of genomic elements. We use a simpler and more intuitive approach to evaluate patterns of genome structure.

Methodology/Principal Findings

We used randomization tests based on Morisita's Index of aggregation to examine average differences in the distribution of purines and pyrimidines among coding and noncoding regions of 261 …


De Novo Characterization Of The Gametophyte Transcriptome In Bracken Fern, Pteridium Aquilinum, J. P. Der, M. S. Barker, N. J. Wickett, C. W. Depamphilis, Paul G. Wolf Jan 2011

De Novo Characterization Of The Gametophyte Transcriptome In Bracken Fern, Pteridium Aquilinum, J. P. Der, M. S. Barker, N. J. Wickett, C. W. Depamphilis, Paul G. Wolf

Biology Faculty Publications

Because of their phylogenetic position and unique characteristics of their biology and life cycle, ferns represent an important lineage for studying the evolution of land plants. Large and complex genomes in ferns combined with the absence of economically important species have been a barrier to the development of genomic resources. However, high throughput sequencing technologies are now being widely applied to non-model species. We leveraged the Roche 454 GS-FLX Titanium pyrosequencing platform in sequencing the gametophyte transcriptome of bracken fern (Pteridium aquilinum) to develop genomic resources for evolutionary studies.


The Evolution Of Chloroplast Genes And Genomes In Ferns, Paul G. Wolf, J. P. Der, A. M. Duffy, J. B. Davidson, A. L. Grusz, K. M. Pryer Jan 2011

The Evolution Of Chloroplast Genes And Genomes In Ferns, Paul G. Wolf, J. P. Der, A. M. Duffy, J. B. Davidson, A. L. Grusz, K. M. Pryer

Biology Faculty Publications

Most of the publicly available data on chloroplast (plastid) genes and genomes come from seed plants, with relatively little information from their sister group, the ferns. Here we describe several broad evolutionary patterns and processes in fern plastid genomes (plastomes), and we include some new plastome sequence data. We review what we know about the evolutionary history of plastome structure across the fern phylogeny and we compare plastome organization and patterns of evolution in ferns to those in seed plants. A large clade of ferns is characterized by a plastome that has been reorganized with respect to the ancestral gene …


The Selaginella Genome Identifies Changes In Gene Content Associated With The Evolution Of Vascular Plants, J. A. Banks, T. Nishiyama, M. Hasebe, J. L. Bowman, M. Gribskov, C. Depamphilis, Paul G. Wolf Jan 2011

The Selaginella Genome Identifies Changes In Gene Content Associated With The Evolution Of Vascular Plants, J. A. Banks, T. Nishiyama, M. Hasebe, J. L. Bowman, M. Gribskov, C. Depamphilis, Paul G. Wolf

Biology Faculty Publications

Vascular plants appeared ~410 million years ago, then diverged into several lineages of which only two survive: the euphyllophytes (ferns and seed plants) and the lycophytes. We report here the genome sequence of the lycophyte Selaginella moellendorffii (Selaginella), the first nonseed vascular plant genome reported. By comparing gene content in evolutionarily diverse taxa, we found that the transition from a gametophyte- to a sporophyte-dominated life cycle required far fewer new genes than the transition from a nonseed vascular to a flowering plant, whereas secondary metabolic genes expanded extensively and in parallel in the lycophyte and angiosperm lineages. Selaginella differs in …


Relative Changes In Krillabundance Inferred From Antarctic Fur Seal, T. Huang, L. Sun, John M. Stark, Y. Wang, Z. Cheng, Q. Yang, S. Sun Jan 2011

Relative Changes In Krillabundance Inferred From Antarctic Fur Seal, T. Huang, L. Sun, John M. Stark, Y. Wang, Z. Cheng, Q. Yang, S. Sun

Biology Faculty Publications

Antarctic krill Euphausia superba is a predominant species in the Southern Ocean, it is very sensitive to climate change, and it supports large stocks of fishes, seabirds, seals and whales in Antarctic marine ecosystems. Modern krill stocks have been estimated directly by net hauls and acoustic surveys; the historical krill density especially the long-term one in the Southern Ocean, however, is unknown. Here we inferred the relative krill population changes along the West Antarctic Peninsula (WAP) over the 20th century from the trophic level change of Antarctic fur seal Arctocephalus gazella using stable carbon (d13C) and nitrogen (d15N) isotopes of …


The Status Of Dwarfed Populations Of Short-Horned Lizards (Phrynosoma Hernandesi) And Great Plains Toads (Anaxyrus Cognatus) In The San Luis Valley, Colorado, Megan E. Lahti Dec 2010

The Status Of Dwarfed Populations Of Short-Horned Lizards (Phrynosoma Hernandesi) And Great Plains Toads (Anaxyrus Cognatus) In The San Luis Valley, Colorado, Megan E. Lahti

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The San Luis Valley is a large valley formation in Colorado surrounded on either side by mountain ranges exceeding 4,267 m. Within the Valley, two of the 14 amphibian and reptile species are dwarfed: the short-horned lizard (Phrynosoma hernandesi) and the Great Plains toad (Anaxyrus cognatus). Since its initial reporting in 1968 and confirmation in 1981, no research further investigating this dwarfism has been conducted. I collected morphological measurements to determine the extent and patterns of dwarfism of both species. I then investigated the genetics of both species using mitochondrial DNA to determine whether they are …


Historical Biogeography Of Velvet Ants (Hymenoptera: Mutillidae) In The North American Deserts And Arid Lands, Joseph S. Wilson Dec 2010

Historical Biogeography Of Velvet Ants (Hymenoptera: Mutillidae) In The North American Deserts And Arid Lands, Joseph S. Wilson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

For centuries, scientists have been intrigued by the high amount of biodiversity that is found in the deserts of North America. Recently, several studies have investigated the causes of the high diversity found in desert-dwelling mammals, reptiles, and amphibians. These studies have found that many of these organisms seem to have diversified in response to the same historical events. Little work has been done, however, on diverse desert-dwelling insect groups. In this dissertation, I investigate the patterns of genetic diversity in four groups of nocturnal wasps called velvet ants. I compare the patterns of genetic diversity to the historical events …


Selective Biochlorination Of Hydroxyquinolines By A Flavin-Dependent Halogenase, Fuchao Xu, Amanda Merkley, Dayu Yu, Jixun Zhan Oct 2010

Selective Biochlorination Of Hydroxyquinolines By A Flavin-Dependent Halogenase, Fuchao Xu, Amanda Merkley, Dayu Yu, Jixun Zhan

Biological Engineering Faculty Publications

Rdc2 is a flavin-dependent halogenase from Pochonia chlamydosporia. Through the introduction of a His6-tag to both the N- and C-termini, the isolation yield of Rdc2 from Escherichia coli using Ni-NTA affinity chromatography was increased by three-fold. In vitro reaction of Rdc2 and a flavin reductase (Fre) with seven different hydroxyquinolines revealed that 3-hydroxyquinoline (3), 5-hydroxyquinoline (5), 6-hydroxyquinoline (6), and 7-hydroxyquinoline (7) can be specifically halogenated. These products were prepared by incubating the corresponding substrates with IPTG-induced E. coli BL21(DE3)/Rdc2. They were respectively characterized as 3-hydroxy-4-chloroquinoline (3a), 5-hydroxy-6-chloroquinoline (5a), 5-chloro-6-hydroxyquinoline (6a), and 7-hydroxy-8-chloroquinoline (7a) by NMR and MS …