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The Emergence Of Sex, Ursula Goodenough Dec 2007

The Emergence Of Sex, Ursula Goodenough

Biology Faculty Research

Biological traits, the foci of natural selection, are by definition emergent from the genes, proteins, and other “nothing-buts” that constitute them. Moreover, and with the exception of recently emergent “spandrels,” each can be accorded a teleological dimension—each is “for” some purpose conducive to an organism's continuation. Sex, which is “for” the generation of recombinant genomes, may be one of the most ancient and ubiquitous traits in biology. In the course of its evolution, many additional traits, such as gender and nurture, have emerged. Patterns of sexual exchange are the basis for patterns of biological evolution and are central to the …


Genomic Resources For Myzus Persicae: Est Sequencing, Snp Identification, And Microarray Design, John S. Ramsey, Alex C. C. Wilson, Marin De Vos, Qi Sun, Cecilia Tamborindeguy, Agnese Winfield, Gaynor Malloch, Dawn M. Smith, Brian Fenton, Stewart M. Gray, Georg Jander Nov 2007

Genomic Resources For Myzus Persicae: Est Sequencing, Snp Identification, And Microarray Design, John S. Ramsey, Alex C. C. Wilson, Marin De Vos, Qi Sun, Cecilia Tamborindeguy, Agnese Winfield, Gaynor Malloch, Dawn M. Smith, Brian Fenton, Stewart M. Gray, Georg Jander

Biology Articles and Papers

Backgorund

The green peach aphid, Myzus persicae (Sulzer), is a world-wide insect pest capable of infesting more than 40 plant families, including many crop species. However, despite the significant damage inflicted by M. persicae in agricultural systems through direct feeding damage and by its ability to transmit plant viruses, limited genomic information is available for this species.

Results

Sequencing of 16 M. persicae cDNA libraries generated 26,669 expressed sequence tags (ESTs). Aphids for library construction were raised on Arabidopsis thaliana, Nicotiana benthamiana, Brassica oleracea, B. napus, and Physalis floridana (with and without Potato leafroll virus infection). The …


Horizontal Transfer Of A Nitrate Assimilation Gene Cluster And Ecological Transitions In Fungi: A Phylogenetic Study, Jason C. Slot, David S. Hibbett Oct 2007

Horizontal Transfer Of A Nitrate Assimilation Gene Cluster And Ecological Transitions In Fungi: A Phylogenetic Study, Jason C. Slot, David S. Hibbett

Biology

High affinity nitrate assimilation genes in fungi occur in a cluster (fHANT-AC) that can be coordinately regulated. The clustered genes include nrt2, which codes for a high affinity nitrate transporter; euknr, which codes for nitrate reductase; and NAD(P)H-nir, which codes for nitrite reductase. Homologs of genes in the fHANT-AC occur in other eukaryotes and prokaryotes, but they have only been found clustered in the oomycete Phytophthora (heterokonts). We performed independent and concatenated phylogenetic analyses of homologs of all three genes in the fHANT-AC. Phylogenetic analyses limited to fungal sequences suggest that the fHANT-AC has been transferred horizontally from a basidiomycete …


Contrasting Infection Strategies In Generalist And Specialist Wasp Parasitoids Of Drosophila Melanogaster, Todd A. Schlenke, Jorge Morales, Shubha Govind, Andrew G. Clark Oct 2007

Contrasting Infection Strategies In Generalist And Specialist Wasp Parasitoids Of Drosophila Melanogaster, Todd A. Schlenke, Jorge Morales, Shubha Govind, Andrew G. Clark

Publications and Research

Although host–parasitoid interactions are becoming well characterized at the organismal and cellular levels, much remains to be understood of the molecular bases for the host immune response and the parasitoids’ ability to defeat this immune response. Leptopilina boulardi and L. heterotoma, two closely related, highly infectious natural parasitoids of Drosophila melanogaster, appear to use very different infection strategies at the cellular level. Here, we further characterize cellular level differences in the infection characteristics of these two wasp species using newly derived, virulent inbred strains, and then use whole genome microarrays to compare the transcriptional response of Drosophila to each. While …


The Effectiveness Of Prophylactic Eye Drops On The Reversal Of Uv-Light Induced Cataracts, Contessa Bly Bowman Oct 2007

The Effectiveness Of Prophylactic Eye Drops On The Reversal Of Uv-Light Induced Cataracts, Contessa Bly Bowman

Theses and Dissertations

Cataracts are a cloudiness of the lens within the eye which obstructs vision. They are found in many species including rats, dogs, and humans. Vision is hindered where this "cloudiness", made of water build up and broken crystalline, proteins take form. Oculvet is an eye medication, used by veterinarians, containing carnosine as its active ingredient. Topical application of carnosine is reported to be an effective treatment for the prevention and removal of pre-existing cataracts. For this experiment, Sprague- Dawley rats were anesthetized and exposed to ultraviolet radiation, UVB and UVC. They were divided into four groups (n = 32), three …


Arbuscular Mycorrhizal Fungal Root Colonization And Inoculum Propagules In Deciduos Floodplain Forests Of Southwestern Michigan, Usa, Peter G. Avis, Sara D. Foster, Paul D. Olexia Oct 2007

Arbuscular Mycorrhizal Fungal Root Colonization And Inoculum Propagules In Deciduos Floodplain Forests Of Southwestern Michigan, Usa, Peter G. Avis, Sara D. Foster, Paul D. Olexia

Faculty and Professional Research

We examined the arbuscular mycorrhizal (AM) fungi of temperate deciduous floodplain forests in southwest Michigan, USA, and the relationship between soil moisture and AM fungal root colonization and inoculum. In four floodplain forests, AM root colonization was measured for roots collected from soil samples taken along soil moisture, micro-topography and vegetation gradients. An AM fungal inoculum bioassay was also conducted using these samples to measure the amount of infective propagules found across these gradients. Although soil moisture had no significant effect on either AM parameter measured, the effect of forest site was significant in most instances. We also found a …


Algal Regulation Of Extracellular Enzyme Activity In Stream Microbial Communities Associated With Inert Substrata And Detritus, Steven T. Rier, Kevin A. Kuehn, Steven N. Francoeur Sep 2007

Algal Regulation Of Extracellular Enzyme Activity In Stream Microbial Communities Associated With Inert Substrata And Detritus, Steven T. Rier, Kevin A. Kuehn, Steven N. Francoeur

Faculty Publications

We tested the hypothesis that algae influence the activities of extracellular enzymes involved in mineralization processes within microbial assemblages in streams. We tested the prediction that the factors that influence algal biomass and photosynthesis (i.e., diel fluctuations in photosynthetically active radiation [PAR], long-term variations in light regime, and community development stage) would have a corresponding effect on extracellular enzyme activities. We also tested the prediction that algae would influence enzyme activities on inorganic substrata and in detrital communities where they ultimately would influence plant litter decomposition rates. We allowed microbial communities to develop on inert substrata (glass-fiber filters) or on …


Survival Of Pacific White Shrimp, , In Low-Salinity And Mixed-Ion Environments, Kirk Parmenter Aug 2007

Survival Of Pacific White Shrimp, , In Low-Salinity And Mixed-Ion Environments, Kirk Parmenter

All Theses

This study was conducted to (1) evaluate the effectiveness of two different salt mixtures, MI-2 (NaCl, MgSO4, MgCl2, KCl, CaCl2, and NaHCO3) and MI (NaCl, MgCl2, KCl, and CaCl2) as compared to artificial sea salt (SS) to provide a sufficient environment for the survival of Litopenaeus vannamei and (2) determine if additions of the MI-2 salt mixture to low concentrations of sea salt would result in comparable survival as that seen in pure SS environments.
Tests conducted at 5 g/L of total dissolved solids showed that the pure SS treatment had a significantly higher survival rate than the MI-2 and …


The Bertalanffy Growth Equation: Theory Of Paulys Auximetric Plots, Eric L. Charnov Jul 2007

The Bertalanffy Growth Equation: Theory Of Paulys Auximetric Plots, Eric L. Charnov

Biology Faculty & Staff Publications

No abstract provided.


Protein Coevolution And Coadaptation In The Vertebrate Bc1 Complex, Kimberly Kay Baer Jul 2007

Protein Coevolution And Coadaptation In The Vertebrate Bc1 Complex, Kimberly Kay Baer

Theses and Dissertations

The cytochrome bc1 complex of the mitochondrial electron transport chain accomplishes the enzymatic reaction known as the modified Q-cycle. In the Q-cycle the bc1 complex transports protons from the matrix to the intermembrane space of the mitochondria, creating the proton gradient used to make ATP. The energy to move these protons is obtained by shuttling electrons from the coenzyme ubiquinol (QH2) to coenzyme ubiquinone (Q) and the mobile cytochrome c. This well studied complex is ideal for examining molecular adaptation because it consists of ten different subunits, it functions as a dimer, and it includes at least five different active …


Direct And Indirect Effects Of Animal Detritus On Growth, Survival, And Mass Of Invasive Container Mosquito Aedes Albopictus (Diptera : Culicidae, Donald A. Yee, Banugopan Kesavaraju, Steven A. Juliano Jul 2007

Direct And Indirect Effects Of Animal Detritus On Growth, Survival, And Mass Of Invasive Container Mosquito Aedes Albopictus (Diptera : Culicidae, Donald A. Yee, Banugopan Kesavaraju, Steven A. Juliano

Faculty Publications – Biological Sciences

Compared with plant detritus, animal detritus yields higher growth rates, survival, adult mass, and population growth of container-dwelling mosquitoes. It is unclear whether the benefit from animal detritus to larvae results from greater microorganism growth, direct ingestion of animal detritus by larvae, or some other mechanism. We tested alternative mechanisms by which animal detritus may benefit the invasive container-dwelling mosquito Aedes albopictus (Skuse) (Diptera: Culicidae). In the laboratory, larvae were reared under three conditions with access to 1) detritus, but where microorganisms in the water column were reduced through periodic flushing; 2) water column microorganisms, but larvae had no direct …


Change In Nutritional Status Modulates The Abundance Of Critical Pre-Initiation Intermediate Complexes During Translation Initiation In Vivo, Chingakham Ranjit Singh, Tsuyoshi Udagawa, Bumjun Lee, Sarah Wassink, Hei He, Yasufumi Yamamoto, James T. Anderson, Graham D. Pavitt, Katsura Asano Jul 2007

Change In Nutritional Status Modulates The Abundance Of Critical Pre-Initiation Intermediate Complexes During Translation Initiation In Vivo, Chingakham Ranjit Singh, Tsuyoshi Udagawa, Bumjun Lee, Sarah Wassink, Hei He, Yasufumi Yamamoto, James T. Anderson, Graham D. Pavitt, Katsura Asano

Biological Sciences Faculty Research and Publications

In eukaryotic translation initiation, eIF2∙GTP–Met-tRNAiMet ternary complex (TC) interacts with eIF3–eIF1–eIF5 complex to form the multifactor complex (MFC), while eIF2∙GDP associates with eIF2B for guanine nucleotide exchange. Gcn2p phosphorylates eIF2 to inhibit eIF2B. Here we evaluate the abundance of eIFs and their pre-initiation intermediate complexes in gcn2 deletion mutant grown under different conditions. We show that ribosomes are three times as abundant as eIF1, eIF2 and eIF5, while eIF3 is half as abundant as the latter three and hence, the limiting component in MFC formation. By quantitative immunoprecipitation, we estimate that ∼ 15% of …


The Effects Of Testosterone On The Induction Of Experimental Autoimmune Thyroiditis In Sprague-Dawley Rats, Travis William Reed Jun 2007

The Effects Of Testosterone On The Induction Of Experimental Autoimmune Thyroiditis In Sprague-Dawley Rats, Travis William Reed

Theses, Dissertations and Culminating Projects

Experimental Autoimmune Thyroiditis (EAT) could not be induced in young, immature Sprague-Dawley rats (150-200g). EAT was successfully induced in the same group of animals when they weighed 400g. The animals developed the disease every time. Sexual immaturity or immaturity of the immune system may be responsible for these results (Fernandez, 2006). It has been proven that pharmacologic doses of testosterone have shown immunosuppressive effects on the severity of EAT in the PVG/c strain of rats (Ahmed et al, 1982). In this current thesis research, it appears that normal physiologic levels of testosterone have no effect on the development and severity …


Structure-Function Studies Of Self- Assembling Flagellin Proteins Fromsalmonella Typhimurium And Aquifex Pyrophilus, Venkata Raghu Ram Malapaka Jun 2007

Structure-Function Studies Of Self- Assembling Flagellin Proteins Fromsalmonella Typhimurium And Aquifex Pyrophilus, Venkata Raghu Ram Malapaka

Dissertations

The eubacterial flagellum is a complex structure with an elongated extracellular filament that is primarily composed of a single protein termed flagellin. The highly conserved N-and C- termini of flagellin are important in its export and assembly, whereas the middle "hypervariable" region is highly variable in size across different species and is largely dispensable. InSalmonella typhimurium phase 1 flagellin (FliC), this hypervariable region encodes two solvent-exposed D2 and D3 domains. The functional role of this knob-like structural feature in motility remains unclear. The structural and physiological role of the hypervariable region in flagellar assembly, stability and cellular motility was investigated. …


Comparative Immune Function In Wild Birds, Kevin David Matson May 2007

Comparative Immune Function In Wild Birds, Kevin David Matson

Dissertations

Over the last several decades, interest in quantifying immune function in comparative studies of wild animals has grown appreciably. Now, the field of ecological immunology is undergoing a transition, and ¿second generation¿ studies are being designed and carried out. With a greater appreciation of the complexity of immune systems, these second generation studies are commonly distinguished from their antecedents by making comparisons using multiple assays and including multiple species. I worked to advance this transition by developing novel approaches to comparative immunology, exploring the interrelationships among indices of immune function, and applying multiple indices to a question of comparative avian …


A Direct Role Of Jh In The Control Of Imaginal Disc Formation And Growth In Manduca, J. W. Truman, K. Hiruma, J. P. Allee, S.G.B. Macwhinnie, David Champlin Ph.D., L. M. Riddiford May 2007

A Direct Role Of Jh In The Control Of Imaginal Disc Formation And Growth In Manduca, J. W. Truman, K. Hiruma, J. P. Allee, S.G.B. Macwhinnie, David Champlin Ph.D., L. M. Riddiford

Faculty Publications

No abstract provided.


Histologic Examination Of Host-Parasite Interactions In The Gulf Killifish, Fundulus Grandis, Marlee Marsh May 2007

Histologic Examination Of Host-Parasite Interactions In The Gulf Killifish, Fundulus Grandis, Marlee Marsh

All Dissertations

Little is known about the immunobiology of fish responses to parasitic infections. The aim of this study was to describe a model for the examination of fish-nematode interactions on the immunological front, and to develop new reagents for the study of this model. Gulf killifish, Fundulus grandis, were collected over two seasons from Simmon's Bayou, Jackson County, MS, USA, pre Hurricane Katrina, and examined for endoparasites, particularly the larval nematode Eustrongylides ignotus. A baseline study was preformed to determine the prevalence, intensity, and histologic features of E. ignotus infection in F. grandis, and this study serves as the first description …


Effects Of Environmental Conditions And Insect Life Stages On Performance Of Entomopathogenic Nematodes For Suppression Of Plum Curculio, Conotrachelus Nenuphar (Coleoptera: Curculionidae), In Northern Utah, Hong Geun Kim May 2007

Effects Of Environmental Conditions And Insect Life Stages On Performance Of Entomopathogenic Nematodes For Suppression Of Plum Curculio, Conotrachelus Nenuphar (Coleoptera: Curculionidae), In Northern Utah, Hong Geun Kim

Biology

In a series of field and laboratory experiments, I tested two entomopathogenic nematode species, two nematode concentrations, and three life stages of the economically damaging insect pest, Contrachelus nenuphar, to support the development of a biological control program for this pest in northern Utah. Two entomopathogenic nematodes, Heterorhabditis bacteriophora and Steinernema feltiae, were tested for their virulence. The population of H. bacteriophora tested was collected from soil infested with plum curculio in Brigham City, UT in 2002. The S. feltiae population was obtained from a commercial source. In temperature bioassays, the two nematodes species exhibited different thermal ranges. …


Screening Candidate Fungicides For Control Of Chalkbrood Disease In Alfalfa Leafcutting Bees, Megachile Rotundata (F.) (Hymenoptera: Megachilidae), Craig Huntzinger May 2007

Screening Candidate Fungicides For Control Of Chalkbrood Disease In Alfalfa Leafcutting Bees, Megachile Rotundata (F.) (Hymenoptera: Megachilidae), Craig Huntzinger

Biology

Pollination of alfalfa seed crops is done primarily by managed populations of the alfalfa leafcutting bee, Megachile rotundata (F.). One of the biggest problems associated with managing M. rotundata on a commercial scale is a fungal disease called chalkbrood, caused by Ascosphaera aggregata Skou. The disease infects larvae that have consumed pollen and nectar contaminated with fungal spores. The spores germinate in the bee's gut, spreading hyphae throughout the host and killing the bee. Mortality from chalkbrood is regularly 10% to 35% in the northwestern United States, and infection levels in excess of 50% are not uncommon. As a consequence, …


A Database Of Wing Diversity In The Hawaiian Drosophila, Kevin A. Edwards, Linden T. Doescher, Kenneth Y. Kaneshiro, Daisuke Yamamoto May 2007

A Database Of Wing Diversity In The Hawaiian Drosophila, Kevin A. Edwards, Linden T. Doescher, Kenneth Y. Kaneshiro, Daisuke Yamamoto

Faculty Publications – Biological Sciences

Background. Within genus Drosophila, the endemic Hawaiian species offer some of the most dramatic examples of morphological and behavioral evolution. The advent of the Drosophila grimshawi genome sequence permits genes of interest to be readily cloned from any of the hundreds of species of Hawaiian Drosophila, offering a powerful comparative approach to defining molecular mechanisms of species evolution. A key step in this process is to survey the Hawaiian flies for characters whose variation can be associated with specific candidate genes. The wings provide an attractive target for such studies: Wings are essentially two dimensional, and genes controlling wing shape, …


The Deleterious Effects Of Bed Rest On Human Skeletal Muscle Fibers Are Exacerbated By Hypercortisolemia And Ameliorated By Dietary Supplementation, Robert H. Fitts, Janell Romatowski, Jim R. Peters, D. Paddon-Jones, R. R. Wolfe, A. A. Ferrando Apr 2007

The Deleterious Effects Of Bed Rest On Human Skeletal Muscle Fibers Are Exacerbated By Hypercortisolemia And Ameliorated By Dietary Supplementation, Robert H. Fitts, Janell Romatowski, Jim R. Peters, D. Paddon-Jones, R. R. Wolfe, A. A. Ferrando

Biological Sciences Faculty Research and Publications

Prolonged inactivity associated with bed rest in a clinical setting or spaceflight is frequently associated with hypercortisolemia and inadequate caloric intake. Here, we determined the effect of 28 days of bed rest (BR); bed rest plus hypercortisolemia (BRHC); and bed rest plus essential amino acid (AA) and carbohydrate (CHO) supplement (BRAA) on the size and function of single slow- and fast-twitch muscle fibers. Supplementing meals, the BRAA group consumed 16.5 g essential amino acids and 30 g sucrose at 1100, 1600, and 2100 h, and the BRHC subjects received 5 daily doses of 10–15 mg of oral hydrocortisone sodium succinate …


Filling Key Gaps In Population And Community Ecology, Anurag A. Agrawal, David D. Ackerly, Fred Adler, A. Elizabeth Arnold, Carla Cáceres, Daniel F. Doak, Eric Post, Peter J. Hudson, John L. Maron, Kailen A. Mooney, Mary Power, Doug Schemske, Jay Stachowicz, Sharon Strauss, Monica G. Turner, Earl Werner Apr 2007

Filling Key Gaps In Population And Community Ecology, Anurag A. Agrawal, David D. Ackerly, Fred Adler, A. Elizabeth Arnold, Carla Cáceres, Daniel F. Doak, Eric Post, Peter J. Hudson, John L. Maron, Kailen A. Mooney, Mary Power, Doug Schemske, Jay Stachowicz, Sharon Strauss, Monica G. Turner, Earl Werner

Biological Sciences Faculty Publications

We propose research to fill key gaps in the areas of population and community ecology, based on a National Science Foundation workshop identifying funding priorities for the next 5–10 years. Our vision for the near future of ecology focuses on three core areas: predicting the strength and context-dependence of species interactions across multiple scales; identifying the importance of feedbacks from individual interactions to ecosystem dynamics; and linking pattern with process to understand species coexistence. We outline a combination of theory development and explicit, realistic tests of hypotheses needed to advance population and community ecology.


Community Composition Of Crustaceans And Gastropods On Caulerpa Prolifera, Halodule Wrightii And Thalassia Testudinum, Jennifer A. Gibson Mar 2007

Community Composition Of Crustaceans And Gastropods On Caulerpa Prolifera, Halodule Wrightii And Thalassia Testudinum, Jennifer A. Gibson

USF Tampa Graduate Theses and Dissertations

No abstract provided.


Invasion By Aegilops Triuncialis (Barb Goatgrass) Slows Carbon And Nutrient Cycling In A Serpentine Grassland, Rebecca E. Drenovsky, Katharine M. Batton Mar 2007

Invasion By Aegilops Triuncialis (Barb Goatgrass) Slows Carbon And Nutrient Cycling In A Serpentine Grassland, Rebecca E. Drenovsky, Katharine M. Batton

Biology

Invasive plant species alter plant community composition and ecosystem function. In the United States, California native grasslands have been displaced almost completely by invasive annual grasses, with serpentine grasslands being one of the few remaining refugia for California grasslands. This study examined how the invasive annual grass, Aegilops triuncialis, has altered decomposition processes in a serpentine annual grassland. Our objectives were to (1) assess howA. triuncialis alters primary productivity and litter tissue chemistry, (2) determine whether A. triuncialis litter is more recalcitrant to decomposition than native litter, and (3) evaluate whether differences in the soil microbial community in A. triuncialis-invaded …


Availability Of Dissolved Organic Matter Offsets Metabolic Costs Of A Protracted Larval Period For Bugula Neritina (Bryozoa), Collin H. Johnson, Dean E. Wendt Mar 2007

Availability Of Dissolved Organic Matter Offsets Metabolic Costs Of A Protracted Larval Period For Bugula Neritina (Bryozoa), Collin H. Johnson, Dean E. Wendt

Biological Sciences

For nearly a century researchers have investigated the uptake and utilization of dissolved organic matter (DOM) by marine invertebrates, but its contribution to their growth, reproduction, and survival remains unclear. Here, the benefit of DOM uptake was assessed for the marine bryozoan Bugula neritina (Linnaeus 1758) through performance comparisons of individuals in the presence and absence of DOM. The experiments were performed using B. neritina collected from floating docks in Beaufort, NC, USA from July to September 2004. Seawater was subjected to ultraviolet irradiation to reduce naturally occurring DOM, and then enriched with either 1 μM of palmitic acid or …


Interspecific And Intraspecific Differences In Foraging Preferences Of Container-Dwelling Mosquitoes, Kesavaraju Banugopan, Donald A. Yee, Steven A. Juliano Mar 2007

Interspecific And Intraspecific Differences In Foraging Preferences Of Container-Dwelling Mosquitoes, Kesavaraju Banugopan, Donald A. Yee, Steven A. Juliano

Faculty Publications – Biological Sciences

Feeding preferences of larval container-dwelling mosquitoes are not well understood. Primary production is often absent in container systems and external inputs of animal and plant detritus supply the energy base of container food webs by supporting microorganism prey for mosquitoes. We quantified the feeding preferences of Aedes albopictus (Skuse), a non-native invasive mosquito, and Ochlerotahts triseriatus (Say), a native mosquito, when given a choice of animal and plant detritus. We tested for interpopulational (Illinois versus Florida) differences in feeding preferences, and quantified each species' performance on these two detritus types. When given a choice, both species spent significantly more time …


Is Oak Establishment In Old‐Fields And Savanna Openings Context Dependent?, Ian A. Dickie, Stefan A. Schnitzer, P. B. Reich, S. E. Hobbie Feb 2007

Is Oak Establishment In Old‐Fields And Savanna Openings Context Dependent?, Ian A. Dickie, Stefan A. Schnitzer, P. B. Reich, S. E. Hobbie

Biological Sciences Faculty Research and Publications

  1. Multiple factors are known to influence tree seedling establishment, yet the degree to which these factors depend on each other and on spatial context is largely unknown. We examined the influence of herbaceous competition and water and nitrogen limitations on tree seedling establishment as functions of distance from trees (within‐site spatial context) and site history (between‐site spatial context; as old‐fields vs. savanna openings).
  2. We grew Quercus ellipsoidalis E.J. Hill (pin oak) and Q. macrocarpa Michx. (bur oak) seedlings for 3 years in abandoned agricultural fields and savannas in central Minnesota, USA, near and distant from adult oak trees, with and …


Aphid Thermal Tolerance Is Governed By A Point Mutation In Bacterial Symbionts, Helen E. Dunbar, Alex C. C. Wilson, Nicole R. Ferguson, Nancy A. Moran Jan 2007

Aphid Thermal Tolerance Is Governed By A Point Mutation In Bacterial Symbionts, Helen E. Dunbar, Alex C. C. Wilson, Nicole R. Ferguson, Nancy A. Moran

Biology Articles and Papers

Symbiosis is a ubiquitous phenomenon generating biological complexity, affecting adaptation, and expanding ecological capabilities. However, symbionts, which can be subject to genetic limitations such as clonality and genomic degradation, also impose constraints on hosts. A model of obligate symbiosis is that between aphids and the bacterium Buchnera aphidicola, which supplies essential nutrients. We report a mutation in Buchnera of the aphid Acyrthosiphon pisum that recurs in laboratory lines and occurs in field populations. This single nucleotide deletion affects a homopolymeric run within the heat-shock transcriptional promoter for ibpA, encoding a small heat-shock protein. This Buchnera mutation virtually eliminates the transcriptional …


Seasonal And Diel Patterns Of Manatee Habitat Use, Monica Ann Ross Jan 2007

Seasonal And Diel Patterns Of Manatee Habitat Use, Monica Ann Ross

Electronic Theses and Dissertations

State and Federal agencies have created sanctuaries and speed zones to help reduce manatee mortality while incorporating the recreational and commercial resource needs of these same habitats for humans. Specific habitat resources are considered necessary to increase manatee survivorship. We have only recently begun to address how manatees use some of these resources based on physiological or reproductive strategies. In this study, I quantified patterns of habitat use during seasonal and diel periods for different sex and reproductive manatee classes using data from a radio-telemetry study conducted by the Florida Fish and Wildlife Conservation Commission during 1991-1996. I used five …


Production Of Methanethiol And Volatile Sulfur Compounds By The Archaeon ‘‘Ferroplasma Acidarmanus’’, David J. Baumler, Kai F. Hung, Kwang Cheol Jeong, Charles W. Kaspar Jan 2007

Production Of Methanethiol And Volatile Sulfur Compounds By The Archaeon ‘‘Ferroplasma Acidarmanus’’, David J. Baumler, Kai F. Hung, Kwang Cheol Jeong, Charles W. Kaspar

Faculty Research & Creative Activity

Acidophiles are typically isolated from sulfaterich ecological niches yet the role of sulfur metabolism in their growth and survival is poorly defined. Studies of heterotrophically grown ‘‘Ferroplasma acidarmanus’’ showed that its growth requires a minimum of 100 mM of a sulfate-containing salt. Headspace gas analyses by GC/ MS determined that the volatile sulfur compound emitted by active ‘‘F. acidarmanus’’ cultures is methanethiol. In ‘‘F. acidarmanus’’ cultures grown either heterotrophically or chemolithotrophically, methanethiol was produced constitutively. Radiotracer studies with 35S-labeled methionine, cysteine, and sulfate showed that all three were used in methanethiol production. Additionally, 3H-labeled methionine was incorporated into methanethiol and …