Life Sciences Commons^™

Prevalence Of Ehrlichia Chaffeensis And Ehrlichia Ewingii In Amblyomma Americanum And Dermacentor Variabilis Collected From Southeastern Virginia, 2010-2011, Chelsea L. Wright, Holly D. Gaff, Wayne L. Hynes

Biological Sciences Faculty Publications

Amblyomma americanum is the most commonly-encountered tick species in southeastern Virginia, representing approximately 95% of the human-biting tick population in this area. Here we investigated the prevalence of Ehrlichia chaffeensis and Ehrlichia ewingii in questing Amblyomma americanum and Dermacentor variabilis ticks collected from multiple sites in southeastern Virginia from 2010–2011. Although both Ehrlichia species were detected in Amblyomma americanum, no evidence of either pathogen was found in Dermacentor variabilis. Prevalence of E. chaffeensis varied by location, ranging from 0 – 5.08% among Amblyomma americanum populations. Ehrlichia ewingii prevalence was slightly higher, ranging from 0 – 8.20% among A. …

Single-Tube Real-Time Pcr Assay For Differentiation Of Ixodes Affinis And Ixodes Scapularis, Chelsea L. Wright, Wayne L. Hynes, Breanna T. White, Mindy N. Marshall, Holly D. Gaff, David T. Gauthier

Biological Sciences Faculty Publications

Ixodes affinis Neumann (1899) and Ixodes scapularis Say (1821) are tick vectors of the etiologic agent of Lyme disease, Borrelia burgdorferi sensu stricto. Ixodes affinis and I. scapularis are morphologically very similar, and as they are sympatric in the mid- and south-Atlantic U.S. coastal states, their accurate identification is crucial to studies of disease and vector ecology in this area. This work describes a rapid, single-tube SYBR® Green-based real-time PCR assay for differentiation of I. affinis and I. scapularis at all life stages. The assay employs 2 pairs of species specific primers directed against the internal transcribed spacer 2 (ITS2) …

Ticks And Spotted Fever Group Rickettsiae Of Southeastern Virginia, Robyn M. Nadolny, Chelsea L. Wright, Daniel E. Sonenshine, Wayne L. Hynes, Holly D. Gaff

Biological Sciences Faculty Publications

The incidence of tick-borne rickettsial disease in the southeastern United States has been rising steadily through the past decade, and the range expansions of tick species and tick-borne infectious agents, new and old, has resulted in an unprecedented mix of vectors and pathogens. The results of an ongoing 4-year surveillance project describe the relative abundance of questing tick populations in southeastern Virginia. Since 2009, more than 66,000 questing ticks of 7 species have been collected from vegetation in a variety of habitats, with Amblyomma americanum constituting over 95% of ticks collected. Other species represented included Ixodes scapularis, Dermacentor variabilis …

Phylogeography Unplugged: Comparative Surveys In The Genomic Era, Brian W. Bowen, Kartik Shanker, Nina Yasuda, Maria Celia Malay, Sophie Von Der Heyden, Gustav Paulay, Luiz A. Rocha, Kimberly A. Selkoe, Paul H. Barber, Suzanne T. Williams, Harilaos A. Lessios, Eric D. Crandall, Giacomo Bernardi, Christopher P. Meyer, Kent E. Carpenter, Robert J. Toonen

Biological Sciences Faculty Publications

In March 2012, the authors met at the National Evolutionary Synthesis Center (NESCent) in Durham, North Carolina, USA, to discuss approaches and cooperative ventures in Indo-Pacific phylogeography. The group emerged with a series of findings: (1) Marine population structure is complex, but single locus mtDNA studies continue to provide powerful first assessment of phylogeographic patterns. (2) These patterns gain greater significance/power when resolved in a diversity of taxa. New analytical tools are emerging to address these analyses with multi-taxon approaches. (3) Genome-wide analyses are warranted if selection is indicated by surveys of standard markers. Such indicators can include discordance between …

Basin Isolation And Oceanographic Features Influencing Lineage Divergence In The Humbug Damselfish (Dascyllus Aruanus) In The Coral Triangle, J. M. Raynal, E. D. Crandall, P. H. Barber, G. N. Mahardika, M. C. Lagman, Kent E. Carpenter

Biological Sciences Faculty Publications

The Coral Triangle is a hotspot for marine species diversity as well as for intraspecific genetic diversity. Here, we used nuclear RAG2 and mitochondrial D-Loop genes to identify deep genetic divergence among Dascyllus aruanus (Linnaeus, 1758) populations across relatively short scales within the Coral Triangle. Mitochondrial clades different by >20 mutational steps were completely isolated from one another across the distance between Java and the Lesser Sunda Islands, and also showed frequency differences in the eastern and western Philippines. Evidence for population structure in the Sulu Sea and at the Lesser Sunda Islands was also identified. Our results suggest that …

Comparison Of Phenology And Pathogen Prevalence, Including Infection With The Ehrlichia Muris-Like (Eml) Agent, Of Ixodes Scapularis Removed From Soldiers In The Midwestern And Northeastern United States Over A 15 Year Period (1997-2012), Ellen Stromdahl, Sarah Hamer, Sarah Jenkins, Lynne Sloan, Phillip Williamson, Erik Foster, Robyn Nadolny, Chad Elkins, Mary Vince, Bobbi Pritt

Biological Sciences Faculty Publications

Background: Since 1997, human-biting ticks submitted to the Department of Defense Human Tick Test Kit Program (HTTKP) of the US Army Public Health Command have been tested for pathogens by PCR. We noted differences in the phenology and infection prevalence among Ixodes scapularis ticks submitted from military installations in different geographic regions. The aim of this study was to characterize these observed differences, comparing the phenology and pathogen infection rates of I. scapularis submitted from soldiers at two sites in the upper Midwest ( Camp Ripley, MN, and Ft. McCoy, WI) and one site in the northeastern US (Ft. Indiantown …

Water As A Trophic Currency In Dryland Food Webs, Daniel C. Allen, Kevin E. Mccluney, Stephen R. Elser, John L. Sabo

Biological Sciences Faculty Publications

Water is essential for life on Earth, yet little is known about how water acts as a trophic currency, a unit of value in determining species interactions in terrestrial food webs. We tested the relative importance of groundwater and surface water in riparian food webs by manipulating their availability in dryland floodplains. Primary consumers (crickets) increased in abundance in response to added surface water and groundwater (contained in moist leaves), and predators (spiders and lizards) increased in abundance in response to added surface water, in spite of the presence of a river, an abundant water source. Moreover, the relative magnitude …

Population Genetic Structure In A Social Landscape: Barley In A Traditional Ethiopian Agricultural System, Leah H. Samberg, Lila Fishman, Fred W. Allendorf

Biological Sciences Faculty Publications

Conservation strategies are increasingly driven by our understanding of the processes and patterns of gene flow across complex landscapes. The expansion of population genetic approaches into traditional agricultural systems requires understanding how social factors contribute to that landscape, and thus to gene flow. This study incorporates extensive farmer interviews and population genetic analysis of barley landraces (Hordeum vulgare) to build a holistic picture of farmer-mediated geneflow in an ancient, traditional agricultural system in the highlands of Ethiopia. We analyze barley samples at 14 microsatellite loci across sites at varying elevations and locations across a contiguous mountain range, and across farmer-identified …

Wolves Facilitate The Recovery Of Browse-Sensitive Understory Herbs In Wisconsin Forests, Krystle Bouchard, Jane E. Wiedenhoeft, Adrian P. Wydeven, Thomas P. Rooney

Biological Sciences Faculty Publications

We asked whether wolf re-colonization would facilitate increased growth and reproduction of three browse-sensitive plant species. We hypothesized plant size and the proportion of reproductive individuals would be lowest in areas with no wolves, intermediate where wolves had been present for 4-6 years, and highest where wolves had been present for 12-13 years. Two plant species exhibited significantly greater reproduction where wolves were present for 12-13 years. Mean leaf size of indicator plants was significantly greater in areas where wolves were present for 12-13 years, as compared with that in areas where wolves were not present or were present for …

Experimental Evolution Of An Alternating Uni- And Multicellular Life Cycle In Chlamydomonas Reinhardtii, William C. Ratcliff, Matthew D. Herron, Kathryn Howell, Jennifer T. Pentz, Frank Rosenzweig, Michael Travisano

Biological Sciences Faculty Publications

The transition to multicellularity enabled the evolution of large, complex organisms, but early steps in this transition remain poorly understood. Here we show that multicellular complexity, including development from a single cell, can evolve rapidly in a unicellular organism that has never had a multicellular ancestor. We subject the alga Chlamydomonas reinhardtii to conditions that favour multicellularity, resulting in the evolution of a multicellular life cycle in which clusters reproduce via motile unicellular propagules. While a single-cell genetic bottleneck during ontogeny is widely regarded as an adaptation to limit among-cell conflict, its appearance very early in this transition suggests that …

Filopodia As Sensors, Carol A. Heckman, H. K. Plummer

Biological Sciences Faculty Publications

Filopodia are sensors on both excitable and non-excitable cells. The sensing function is well documented in neurons and blood vessels of adult animals and is obvious during dorsal closure in embryonic development. Nerve cells extend neurites in a bidirectional fashion with growth cones at the tips where filopodia are concentrated. Their sensing of environmental cues underpins the axon's ability to "guide," bypassing non-target cells and moving toward the target to be innervated. This review focuses on the role of filopodia structure and dynamics in the detection of environmental cues, including both the extracellular matrix (ECM) and the surfaces of neighboring …

Sequestration And Scavenging Of Iron In Infection, Nermi Lee Parrow, Robert E. Fleming, Michael F. Minnick

Biological Sciences Faculty Publications

The proliferative capability of many invasive pathogens is limited by the bioavailability of iron. Pathogens have thus developed strategies to obtain iron from their host organisms. In turn, host defense strategies have evolved to sequester iron from invasive pathogens. This review explores the mechanisms employed by bacterial pathogens to gain access to host iron sources, the role of iron in bacterial virulence, and iron-related genes required for the establishment or maintenance of infection. Host defenses to limit iron availability for bacterial growth during the acute-phase response and the consequences of iron overload conditions on susceptibility to bacterial infection are also …

Tossing The Coin For Half Life, William L. Romine

Biological Sciences Faculty Publications

No abstract provided.

Bacterial Endophytes Enhance Competition By Invasive Plants, Marnie E. Rout, Thomas H. Chrzanowski, Tara K. Westlie, Thomas H. Deluca, Ragan M. Callaway, William E. Holben

Biological Sciences Faculty Publications

• Premise of the study: Invasive plants can alter soil microbial communities and profoundly alter ecosystem processes. In the invasive grass Sorghum halepense, these disruptions are consequences of rhizome-associated bacterial endophytes. We describe the effects of N₂-fixing bacterial strains from S. halepense (Rout and Chrzanowski, 2009) on plant growth and show that bacteria interact with the plant to alter soil nutrient cycles, enabling persistence of the invasive.
• Methods: We assessed fluxes in soil nutrients for ~4 yr across a site invaded by S. halepense. We assayed the N₂-fixing bacteria in vitro for phosphate solubilization, …

The Science (And Pseudoscience) Of Dna Profiling, Dan E. Krane

Biological Sciences Faculty Publications

No abstract provided.

An Acid Test For G Proteins, Stephen R. Sprang

Biological Sciences Faculty Publications

Heterotrimeric G proteins are cytoplasmic transducers of signals generated by ligandactivated 7-transmembrane receptors (G protein-coupled receptors, or GPCRs) embedded in the plasma membranes of cells. GPCRs activate G proteins by catalyzing exchange of GDP for GTP at the alpha subunit (Gα) with the concomitant release of the Gβγ heterodimer. Separately or together Gα•GTP and Gβγ stimulate enzymes that produce second messengers (e.g. cyclic AMP), control ion channels, Ras-family G proteins and regulate transcription (Cabrera-Vera et al., 2003). In yeast, GPCRs intercept mating pheromones and monitor extracellular glucose concentration, and so generate intracellular signals either to arrest growth or to proliferate. …

Neurotensin And Cholecystokinin Contract Gallbladder Circular Muscle In Chickens, Teresa F. Degolier, D. R. Brown, Gary E. Duke, M. M. Palmer, J. R. Swenson, Robert E. Carraway

Biological Sciences Faculty Publications

The contractile effects of neurotensin (NT) and cholecystokinin octapeptide (CCK-8) on isolated circular smooth muscle strips of chicken gallbladder were investigated. The NT (0.25-300 nM) produced concentration-dependent contractions on smooth muscle with an EC50 of 8.5 nM (95% confidence limits = 5.3-13.6 nM). In comparison, CCK-8 produced concentration-dependent contractions with an EC50 of 13 nM (95% confidence limits of 9-20 nM). There were no statistical differences in contractile responses when comparing NT and CCK-8 at equimolar concentrations. The NT appears to act directly on smooth muscle tissue in the chicken; the contractile responses were not blocked by 10 μM atropine …

Rcytoscape: Tools For Exploratory Network Analysis, Paul Shannon, Mark L. Grimes, Burak Kutlu, Jan J. Bit, David J. Galas

Biological Sciences Faculty Publications

Background: Biomolecular pathways and networks are dynamic and complex, and the perturbations to them which cause disease are often multiple, heterogeneous and contingent. Pathway and network visualizations, rendered on a computer or published on paper, however, tend to be static, lacking in detail, and ill-equipped to explore the variety and quantities of data available today, and the complex causes we seek to understand.

Results: RCytoscape integrates R (an open-ended programming environment rich in statistical power and datahandling facilities) and Cytoscape (powerful network visualization and analysis software). RCytoscape extends Cytoscape's functionality beyond what is possible with the Cytoscape graphical user interface. …

An Inverted Repeat In The Ospc Operator Is Required For Induction In Borrelia Burgdorferi, Dan Drecktrah, Laura S. Hall, Laura L. Hoon-Hanks, D. Scott Samuels

Biological Sciences Faculty Publications

Borrelia burgdorferi, the spirochete that causes Lyme disease, differentially regulates synthesis of the outer membrane lipoprotein OspC to infect its host. OspC is required to establish infection but then repressed in the mammal to avoid clearance by the adaptive immune response. Inverted repeats (IR) upstream of the promoter have been implicated as an operator to regulate ospC expression. We molecularly dissected the distal inverted repeat (dIR) of the ospC operator by site-directed mutagenesis at its endogenous location on the circular plasmid cp26. We found that disrupting the dIR but maintaining the proximal IR prevented induction of OspC synthesis by …

Starvation-Associated Genome Restructuring Can Lead To Reproductive Isolation In Yeast, Evgueny Kroll, Scott Coyle, Barbara Dunn, Gregory Koniges, Anthony Aragon, Jeremy Edwards, Frank Rosenzweig

Biological Sciences Faculty Publications

Knowledge of the mechanisms that lead to reproductive isolation is essential for understanding population structure and speciation. While several models have been advanced to explain post-mating reproductive isolation, experimental data supporting most are indirect. Laboratory investigations of this phenomenon are typically carried out under benign conditions, which result in low rates of genetic change unlikely to initiate reproductive isolation. Previously, we described an experimental system using the yeast Saccharomyces cerevisiae where starvation served as a proxy to any stress that decreases reproduction and/or survivorship. We showed that novel lineages with restructured genomes quickly emerged in starved populations, and that these …

Subglacial Lake Vostok (Antarctica) Accretion Ice Contains A Diverse Set Of Sequences From Aquatic, Marine And Sediment-Inhabiting Bacteria And Eukarya, Scott O. Rogers, Yury M. Shtarkman, Zeynep A. Koçer, Robyn Edgar, Ram S. Veerapneni, Tom D'Elia, Paul F. Morris

Biological Sciences Faculty Publications

Lake Vostok, the 7th largest (by volume) and 4th deepest lake on Earth, is covered by more than 3,700 m of ice, making it the largest subglacial lake known. The combination of cold, heat (from possible hydrothermal activity), pressure (from the overriding glacier), limited nutrients and complete darkness presents extreme challenges to life. Here, we report metagenomic/metatranscriptomic sequence analyses from four accretion ice sections from the Vostok 5G ice core. Two sections accreted in the vicinity of an embayment on the southwestern end of the lake, and the other two represented part of the southern main basin. We obtained 3,507 …

Breed Locally, Disperse Globally: Fine-Scale Genetic Structure Despite Landscape-Scale Panmixia In A Fire-Specialist, Jennifer C. Pierson, Fred W. Allendorf, Pierre Drapeau, Michael K. Schwartz

Biological Sciences Faculty Publications

An exciting advance in the understanding of metapopulation dynamics has been the investigation of how populations respond to ephemeral patches that go 'extinct' during the lifetime of an individual. Previous research has shown that this scenario leads to genetic homogenization across large spatial scales. However, little is known about fine-scale genetic structuring or how this changes over time in ephemeral patches. We predicted that species that specialize on ephemeral habitats will delay dispersal to exploit natal habitat patches while resources are plentiful and thus display fine-scale structure. To investigate this idea, we evaluated the effect of frequent colonization of ephemeral …

Environment, Behavior And Physiology: Do Birds Use Barometric Pressure To Predict Storms?, Creagh W. Breuner, Rachel Seabury Sprague, Stephen Harold Patterson, H. Arthur Woods

Biological Sciences Faculty Publications

Severe storms can pose a grave challenge to the temperature and energy homeostasis of small endothermic vertebrates. Storms are accompanied by lower temperatures and wind, increasing metabolic expenditure, and can inhibit foraging, thereby limiting energy intake. To avoid these potential problems, most endotherms have mechanisms for offsetting the energetic risks posed by storms. One possibility is to use cues to predict oncoming storms and to alter physiology and behavior in ways that make survival more likely. Barometric pressure declines predictably before inclement weather, and several lines of evidence indicate that animals alter behavior based on changes in ambient pressure. Here …

Effects Of Experimentally Elevated Traffic Noise On Nestling White-Crowned Sparrow Stress Physiology, Immune Function And Life History, Ondi L. Crino, Erin E. Johnson, Jessica L. Blickley, Gail L. Patricelli, Creagh W. Breuner

Biological Sciences Faculty Publications

Roads have been associated with behavioral and physiological changes in wildlife. In birds, roads decrease reproductive success and biodiversity and increase physiological stress. Although the consequences of roads on individuals and communities have been well described, the mechanisms through which roads affect birds remain largely unexplored. Here, we examine one mechanism through which roads could affect birds: traffic noise. We exposed nestling mountain white-crowned sparrows (Zonotrichia leucophrys oriantha) to experimentally elevated traffic noise for 5 days during the nestling period. Following exposure to traffic noise we measured nestling stress physiology, immune function, body size, condition and survival. Based …

Native Congeners Provide Biotic Resistance To Invasive Potentilla Through Soil Biota, Ragan M. Callaway, Daniel Montesinos, Kimberlyn Williams, John L. Maron

Biological Sciences Faculty Publications

Soil biota can facilitate exotic plant invasions and these effects can be influenced by specific phylogenetic relationships among plant taxa. We measured the effects of sterilizing soils from different native plant monocultures on the growth of Potentilla recta, an exotic invasive forb in North America, and conducted plant–soil feedback experiments with P. recta, two native congeners, a close confamilial, and Festuca idahoensis, a native grass species. We also reanalyzed data comparing the ability of P. recta to invade experimentally constructed congeneric monocultures vs. monocultures of a broad suite of non-congeners. We found that monocultures as a group, …

Three-Dimensional, High-Resolution Skeletal Kinematics Of The Avian Wing And Shoulder During Ascending Flapping Flight And Uphill Flap-Running, David B. Baier, Stephen M. Gatesy, Kenneth P. Dial

Biological Sciences Faculty Publications

Past studies have shown that birds use their wings not only for flight, but also when ascending steep inclines. Uphill flap-running or wing-assisted incline running (WAIR) is used by both flight-incapable fledglings and flight-capable adults to retreat to an elevated refuge. Despite the broadly varying direction of travel during WAIR, level, and descending flight, recent studies have found that the basic wing path remains relatively invariant with reference to gravity. If so, joints undergo disparate motions to maintain a consistent wing path during those specific flapping modes. The underlying skeletal motions, however, are masked by feathers and skin. To improve …

The Early Dissemination Defect Attributed To Disruption Of Decorin-Binding Proteins Is Abolished In Chronic Murine Lyme Borreliosis, Denise M. Imai, D. Scott Samuels, Sunlian Feng, Emir Hodzic, Kim Olsen, Stephen W. Barthold

Biological Sciences Faculty Publications

The laboratory mouse model of Lyme disease has revealed that Borrelia burgdorferi differentially expresses numerous outer surface proteins that influence different stages of infection (tick-borne transmission, tissue colonization, dissemination, persistence, and tick acquisition). Deletion of two such outer surface proteins, decorin-binding proteins A and B (DbpA/B), has been documented to decrease infectivity, impede early dissemination, and, possibly, prevent persistence. In this study, DbpA/B-deficient spirochetes were confirmed to exhibit an early dissemination defect in immunocompetent, but not immunodeficient, mice, and the defect was found to resolve with chronicity. Development of disease (arthritis and carditis) was attenuated only in the early stage …

A Field Experiment Demonstrating Plant Life-History Evolution And Its Eco-Evolutionary Feedback To Seed Predator Populations, Anurag A. Agrawal, Marc T. J. Johnson, Amy P. Hastings, John L. Maron

Biological Sciences Faculty Publications

The extent to which evolutionary change occurs in a predictable manner under field conditions and how evolutionary changes feed back to influence ecological dynamics are fundamental, yet unresolved, questions. To address these issues, we established eight replicate populations of native common evening primrose (Oenothera biennis). Each population was planted with 18 genotypes in identical frequency. By tracking genotype frequencies with microsatellite DNA markers over the subsequent three years (up to three generations, approximate to 5,000 genotyped plants), we show rapid and consistent evolution of two heritable plant life-history traits (shorter life span and later flowering time). This rapid evolution was …

Distribution, Prevalence, And Genetic Analysis Of Panulirus Argus Virus 1 (Pav1) From The Caribbean Sea, Jessica Moss, Donald C. Behringer Jr., Jeffrey D. Shields, Antonio Baeza, Alfonso Aguilar-Perera, Phillippe G. Bush, Clement Dromer, Alejandro Herrera-Moreno, Lester Gittens, Thomas R. Matthews, Michael R. Mccord, Michelle T. Schärer, Lionel Reynal, Nathanial Truelove, Mark J. Butler Iv

Biological Sciences Faculty Publications

The pathogenic virus Panulirus argus virus 1 (PaV1) was first discovered in Caribbean spiny lobsters Panulirus argus from the Florida Keys (USA) in 1999 and has since been reported in Belize, Mexico, and Cuba; its distribution in the wider Caribbean is unknown. We collected tissue samples from adult spiny lobsters from 30 locations in 14 countries bordering the Caribbean Sea and used molecular diagnostics to assay for the presence of PaV1. PaV1 occurred primarily in the northern areas of the Caribbean, where its prevalence was highest. The virus was not found in lobsters from the southeastern Caribbean, and its prevalence …

Sh3 Interactome Conserves General Function Over Specific Form, Xiaofeng Xin, David Gfeller, Jackie Cheng, Raffi Tonikian, Lin Sun, Ailan Guo, Lianet Lopez, Alevtina Pavlenco, Adenrele Akintobi, Yingnan Zhang, Jean-Francois Rual, Bridget Currell, Somasekar Seshagiri, Tong Hao, Xinping Yang, Yun A. Shen, Kourosh Salehi-Ashtiani, Jingjing Li, Aaron T. Cheng, Dryden Bouamalay, Adrien Lugari, David E. Hill, Mark L. Grimes, David. G. Drubin, Barth D. Grant, Marc Vidal, Charles Boone, Sachdev S. Sidhu, Gary D. Bader

Biological Sciences Faculty Publications

Src homology 3 (SH3) domains bind peptides to mediate protein–protein interactions that assemble and regulate dynamic biological processes. We surveyed the repertoire of SH3 binding specificity using peptide phage display in a metazoan, the worm Caenorhabditis elegans, and discovered that it structurally mirrors that of the budding yeast Saccharomyces cerevisiae.We then mapped the worm SH3 interactome using stringent yeast two-hybrid and compared it with the equivalent map for yeast.We found that the wormSH3 interactome resembles the analogous yeast network because it is significantly enriched for proteins with roles in endocytosis. Nevertheless, orthologous SH3 domain mediated interactions are highly …