Life Sciences Commons^™

Multilayered Structure Of Tension Wood Cell Walls In Salicaceae Sensu Lato And Its Taxonomic Significance, Barbara Ghislain, Eric-André Nicolini, Raïssa Romain, Julien Ruelle, Arata Yoshinaga, Mac H. Alford, Bruno Clair

Faculty Publications

Salicaceae have been enlarged to include a majority of the species formerly placed in the polyphyletic tropical Flacourtiaceae. Several studies have reported a peculiar and infrequently formed multilayered structure of tension wood in four of the tropical genera. Tension wood is a tissue produced by trees to restore their vertical orientation and most studies have focused on trees developing tension wood by means of cellulose-rich, gelatinous fibres, as in Populus and Salix (Salicaceae s.s.). This study aims to determine if the multilayered structure of tension wood is an anatomical characteristic common in other Salicaceae and, if so, how its …

Tlr8 Couples Socs-1 And Restrains Tlr7-Mediated Antiviral Immunity, Exacerbating West Nile Virus Infection In Mice, Amber M. Paul, Dhiraj Acharya, Linda Le, Penghua Wang, Dobrivoje S. Stokic, A. Arturo Leis, Lena Alexopoulou, Terrence Town, Richard A. Flavell, Erol Fikrig, Fengwei Bai

Faculty Publications

West Nile virus (WNV) is a neurotropic ssRNA flavivirus that can cause encephalitis, meningitis, and death in humans and mice. Human TLR7 and TLR8 and mouse TLR7 recognize viral ssRNA motifs and induce antiviral immunity. However, the role of mouse TLR8 in antiviral immunity is poorly understood. In this article, we report that TLR8-deficient (Tlr8−/−) mice were resistant to WNV infection compared with wild-type controls. Efficient WNV clearance and moderate susceptibility to WNV-mediated neuronal death in Tlr8−/− mice were attributed to overexpression of Tlr7and IFN-stimulated gene-56 expression, whereas reduced expression of the proapoptotic gene coding Bcl2-associated X protein was observed. …

Fluctuating Temperatures Alter Environmental Pathogen Transmission In A Daphnia–Pathogen System, Tad Dallas, John M. Drake

Faculty Publications

Environmental conditions are rarely constant, but instead vary spatially and temporally. This variation influences ecological interactions and epidemiological dynamics, yet most experimental studies examine interactions under constant conditions. We examined the effects of variability in temperature on the host–pathogen relationship between an aquatic zooplankton host (Daphnia laevis) and an environmentally transmitted fungal pathogen (Metschnikowia bicuspidata). We manipulated temperature variability by exposing all populations to mean temperatures of 20°C for the length of the experiments, but introducing periods of 1, 2, and 4 hr each day where the populations were exposed to 28°C followed by periods of …

Genome Sequence Of Mycobacterium Phage Waterfoul, Paige N. Jackson, Ella K. Embry, Christa O. Johnson, Jessica R. Douglas, J. Michael Sellers, William A. D'Angelo, Dmitri V. Mavrodi

Faculty Publications

Waterfoul is a new isolated temperate siphovirus of Mycobacterium smegmatis mc²155. It was identified as a member of the K5 cluster of Mycobacterium phages and has a 61,248-bp genome with 95 predicted genes."

Ordination Obscures The Influence Of Environment On Plankton Metacommunity Structure, Tad Dallas, Andrew M. Kramer, Marcus Zokan, John M. Drake

Faculty Publications

The composition of plankton communities in individual habitats is often influenced by environmental conditions like pH or hydroperiod. At larger scales, environmental gradients can influence community structure across interconnected local communities. Detecting the role of environmental and spatial factors on metacommunity structure depends on the ordering of sites and species prior to analysis. We investigated this ordination in two wetland metacommunities; a well-sampled, hyper-diverse zooplankton metacommunity, and a Central American phytoplankton metacommunity. We calculated coherence, turnover, and boundary clumping to classify the structure of the metacommunity, and we propose a statistic that responds to variation in both coherence and turnover. …

Pyruvate Oxidase Of Streptococcus Pneumoniae Contributes To Penumolysin Release, Joseph C. Bryant, Ridge C. Dabbs, Katie L. Oswalt, Lindsey R. Brown, Jason W. Rosch, Keun S. Seo, Janet R. Donaldson, Larry S. Mcdaniel, Justin A. Thornton

Faculty Publications

Background

Streptococcus pneumoniae is one of the leading causes of community acquired pneumonia and acute otitis media. Certain aspects of S. pneumoniae’s virulence are dependent upon expression and release of the protein toxin pneumolysin (PLY) and upon the activity of the peroxide-producing enzyme, pyruvate oxidase (SpxB). We investigated the possible synergy of these two proteins and identified that release of PLY is enhanced by expression of SpxB prior to stationary phase growth.

Results

Mutants lacking the <>spxB gene were defective in PLY release and complementation of spxB restored PLY release. This was demonstrated by cytotoxic effects of sterile filtered …

Fluctuating Asymmetry In Two Common Freshwater Fishes As A Biological Indicator Of Urbanization And Environmental Stress Within The Middle Chattahoochee Watershed, William I. Lutterschmidt, Samantha L. Martin, Jacob F. Schaefer

Faculty Publications

Deviations in bilateral symmetry or fluctuating asymmetry of an organism may result under environmental stressors that reduce developmental homeostasis and stability. Anthropogenic stressors such as increased urbanization can negatively impact environmental quality of aquatic ecosystems. Researchers have stressed the value in finding easy, accurate and inexpensive methods for assessing potential stress within ecosystems. Here we use fluctuating asymmetry (FA) as a useful quantitative tool in assessing the environmental quality and potential urban-based stressors within eight creeks of the Bull and Upatoi Creeks Watershed within the larger watershed of the Middle Chattahoochee. Using Geographic Information System (GIS), we characterize land-use patterns …

The Mirror-Based Eyes Of Scallops Demonstrate A Light-Evoked Pupillary Response, M. Desmond Ramirez, Autum N. Pairett, M. Sabrina Pankey, Jeanne M. Serb, Daniel Isaac Speiser, Andrew J. Swafford, Todd H. Oakley

Faculty Publications

The opsin gene family encodes key proteins animals use to sense light and has expanded dramatically as it originated early in animal evolution. Understanding the origins of opsin diversity can offer clues to how separate lineages of animals have repurposed different opsin paralogs for different light-detecting functions. However, the more we look for opsins outside of eyes and from additional animal phyla, the more opsins we uncover, suggesting we still do not know the true extent of opsin diversity, nor the ancestry of opsin diversity in animals. To estimate the number of opsin paralogs present in both the last common …

Sources, Distributions And Dynamics Of Dissolved Organic Matter In The Canada And Makarov Basins, Yuan Shen, Ronald Benner, Lisa L. Robbins, Jonathan G. Wynn

Faculty Publications

A comprehensive survey of dissolved organic carbon (DOC) and chromophoric dissolved organic matter (CDOM) was conducted in the Canada and Makarov Basins and adjacent seas during 2010–2012 to investigate the dynamics of dissolved organic matter (DOM) in the Arctic Ocean. Sources and distributions of DOM in polar surface waters were very heterogeneous and closely linked to hydrological conditions. Canada Basin surface waters had relatively low DOC concentrations (69 ± 6 μmol L−1), CDOM absorption (a325: 0.32 ± 0.07 m−1) and CDOM-derived lignin phenols (3 ± 0.4 nmol L−1), and high spectral slope values (S275–295: 31.7 ± …

Coastal Wetland Response To Sea‐Level Rise In A Fluvial Estuarine System, Karim Alizad, Scott C. Hagen, James T. Morris, Stephen C. Medeiros, Matthew V. Bilskie, John F. Weishampel

Faculty Publications

Coastal wetlands are likely to lose productivity under increasing rates of sea‐level rise (SLR). This study assessed a fluvial estuarine salt marsh system using the Hydro‐MEM model under four SLR scenarios. The Hydro‐MEM model was developed to apply the dynamics of SLR as well as capture the effects associated with the rate of SLR in the simulation. Additionally, the model uses constants derived from a 2‐year bioassay in the Apalachicola marsh system. In order to increase accuracy, the lidar‐based marsh platform topography was adjusted using Real Time Kinematic survey data. A river inflow boundary condition was also imposed to simulate …

Diversity As Opportunity: Insights From 600 Million Years Of Ahr Evolution, Rebeka R. Merson, Mark E. Hahn, Sibel I. Karchner

Faculty Publications

The aryl hydrocarbon receptor (AHR) was for many years of interest only to pharmacologists and toxicologists. However, this protein has fundamental roles in biology that are being revealed through studies in diverse animal species. The AHR is an ancient protein. AHR homologs exist in most major groups of modern bilaterian animals, including deuterostomes (chordates, hemichordates, echinoderms) and the two major clades of protostome invertebrates [ecdysozoans (e.g. arthropods and nematodes) and lophotrochozoans (e.g. molluscs and annelids)]. AHR homologs also have been identified in cnidarians such as the sea anemone Nematostella and in the genome of Trichoplax, a placozoan. Bilaterians, cnidarians, and …

A Snapshot Of The Microbiome Of Ambylomma Tuberculatum Ticks Infesting The Gopher Tortoise, An Endangered Species, Khemraj Budachetri, Daniel Lyle Gaillard, Jaclyn Bo Williams, Nabanita Mukherjee, Shahid Karim

Faculty Publications

The gopher tortoise tick, Amblyomma tuberculatum, has a unique relationship with the gopher tortoise, Gopherus polyphemus, found in sandy habitats across the southeastern United States. We aimed to understand the overall bacterial community associated with A. tuberculatum while also focusing on spotted fever group Rickettsia. These tortoises in the Southern Mississippi region are a federally threatened species; therefore, we have carefully trapped the tortoises and removed the species-specific ticks attached to them. Genomic DNA was extracted from individual ticks and used to explore overall bacterial load using pyrosequencing of bacterial 16S rRNA on 454-sequencing platform. The spotted fever group …

New Circumspection Of The Genus Gamochaeta (Asteraceae, Gnaphalieae) Inferred From Nuclear And Plastid Dna Sequences, Estrella Urtubey, Alicia López, María A. Chemisquy, Arne A. Anderberg, Carlos M. Baeza, Néstor D. Bayón, Leonardo P. Deble, Andrés Moreira-Muñoz, Guy L. Nesom, Mac H. Alford, Luciana Salomón, Susana E. Freire

Faculty Publications

Gamochaeta (tribe Gnaphalieae, Asteraceae) is composed of ca. 60 species primarily distributed in tropical and subtropical America. Within the tribe Gnaphalieae, the genus is characterized by capitula arranged in spikes or head-like clusters, few hermaphroditic central florets, truncate style branches with apical sweeping trichomes, pappus bristles connate at the base into a ring falling as a unit, and achenes with globose twin trichomes. Previous molecular phylogenetic studies have suggested the paraphyly of the genus, but have not provided a basis for redefining generic limits due to incomplete taxon sampling. To address this problem, DNA sequences from the plastid (trn …

Nitrogen Loading Leads To Increased Carbon Accretion In Both Invaded And Uninvaded Coastal Wetlands, Jason P. Martina, William S. Currie, Deborah E. Goldberg, Kenneth J. Elgersma

Faculty Publications

Gaining a better understanding of carbon (C) dynamics across the terrestrial and aquatic landscapes has become a major research initiative in ecosystem ecology. Wetlands store a large portion of the global soil C, but are also highly dynamic ecosystems in terms of hydrology and N cycling, and are one of the most invaded habitats worldwide. The interactions between these factors are likely to determine wetland C cycling, and specifically C accretion rates. We investigated these interactions using MONDRIAN, an individual-based model simulating plant growth and competition and linking these processes to N and C cycling. We simulated the effects of …

Different Roads Lead To Rome: Integrative Taxonomic Approaches Lead To The Discovery Of Two New Lizard Lineages In The Liolaemus Montanus Group (Squamata: Liolaemidae), Cesar Aguilar, Perry L. Wood Jr., Mark C. Belk, Mike H. Duff, Jack W. Sites Jr.

Faculty Publications

Integrative taxonomy (IT) is becoming a preferred approach to delimiting species boundaries by including different empirical criteria. IT methods can be divided into two types of procedures both of which use multiple kinds of evidence: step-by-step approaches test hypotheses by sequential evaluation in a hypothetic-deductive framework, while model-based procedures delimit groups based on statistical information criteria. In this study we used a step-by-step approach and a Gaussian clustering (GC) method to test species boundaries in the northernmost species of the Liolaemus montanus group. We used different methods based on mitochondrial and nuclear DNA sequence data, morphological measures and niche envelope …

Environmental Conditions Of 2 River Drainages Into The Northern Gulf Of Mexico During Successful Hatching Of Alabama Shad (Alosa Alabamae), Paul F. Mickle, Jacob F. Schaefer, Susan B. Adams, Brian R. Kreiser, William T. Slack

Faculty Publications

In recent years, the Alabama shad (Alosa alabamae) has experienced dramatic declines and extirpations from portions of its native range. Habitat degradation and barriers to migration are considered contributing factors to contraction in the distributional range this species. To identify conditions during successful spawning, river temperatures and discharges in 2 drainages of the northern Gulf of Mexico (the Apalachicola and Pascagoula rivers) were characterized during successful hatching “windows.” Sampling during 2005–2009 yielded 400 juvenile Alabama shad of which 261 were aged from counts of rings on sagittal otoliths. Results from logistic regression revealed that successful spawning coincided with increases in …

The Mitochondrial Cytochrome Oxidase Subunit I Gene Occurs On A Minichromosome With Extensive Heteroplasmy In Two Species Of Chewing Lice, Geomydoecus Aurei And Thomomydoecus Minor, Lucas L. Pietan, Theresa A. Spradling, James W. Demastes

Faculty Publications

In animals, mitochondrial DNA (mtDNA) typically occurs as a single circular chromosome with 13 protein-coding genes and 22 tRNA genes. The various species of lice examined previously, however, have shown mitochondrial genome rearrangements with a range of chromosome sizes and numbers. Our research demonstrates that the mitochondrial genomes of two species of chewing lice found on pocket gophers, Geomydoecus aurei and Thomomydoecus minor, are fragmented with the 1,536 base-pair (bp) cytochrome-oxidase subunit I (cox1) gene occurring as the only protein-coding gene on a 1,916–1,964 bp minicircular chromosome in the two species, respectively. The cox1 gene of T. …

An Ultrasensitive Electrogenerated Chemiluminescence-Based Immunoassay For Specific Detection Of Zika Virus, Dhiraj Acharya, Pradip Bastola, Linda Le, Amber M. Paul, Estefania Fernandez, Michael S. Diamond, Wujian Miao, Fengwei Bai

Faculty Publications

Zika virus (ZIKV) is a globally emerging mosquito-transmitted flavivirus that can cause severe fetal abnormalities, including microcephaly. As such, highly sensitive, specific, and cost-effective diagnostic methods are urgently needed. Here, we report a novel electrogenerated chemiluminescence (ECL)-based immunoassay for ultrasensitive and specific detection of ZIKV in human biological fluids. We loaded polystyrene beads (PSB) with a large number of ECL labels and conjugated them with anti-ZIKV monoclonal antibodies to generate anti-ZIKV-PSBs. These anti-ZIKV-PSBs efficiently captured ZIKV in solution forming ZIKV-anti-ZIKV-PSB complexes, which were subjected to measurement of ECL intensity after further magnetic beads separation. Our results show that the anti-ZIKV-PSBs …

Examining The Effects Of Chromatic Aberration, Object Distance, And Eye Shape On Image-Formation In The Mirror-Based Eyes Of The Bay Scallop Argopecten Irradians, Daniel Isaac Speiser, Yakir Luc Gagnon, Raghav K. Chhetri, Amy L. Oldenburg, Sönke Johnsen

Faculty Publications

The eyes of scallops form images using a concave spherical mirror and contain two separate retinas, one layered on top of the other. Behavioral and electrophysiological studies indicate that the images formed by these eyes have angular resolutions of about 2°. Based on previous ray-tracing models, it has been thought that the more distal of the two retinas lies near the focal point of the mirror and that the proximal retina, positioned closer to the mirror at the back of the eye, receives light that is out-of-focus. Here, we propose three mechanisms through which both retinas may receive focused light: …

Examining The Effects Of Chromatic Aberration, Object Distance, And Eye Shape On Image-Formation In The Mirror-Based Eyes Of The Bay Scallop Argopecten Irradians, Daniel Isaac Speiser, Yakir Luc Gagnon, Raghav K. Chhetri, Amy L. Oldenburg, Sönke Johnsen

Faculty Publications

The eyes of scallops form images using a concave spherical mirror and contain two separate retinas, one layered on top of the other. Behavioral and electrophysiological studies indicate that the images formed by these eyes have angular resolutions of about 28. Based on previous ray-tracing models, it has been thought that the more distal of the two retinas lies near the focal point of the mirror and that the proximal retina, positioned closer to the mirror at the back of the eye, receives light that is out-of-focus. Here, we propose three mechanisms through which both retinas may receive focused light: …

Developmental Functions Of Mir156-Regulated Squamosa Promoter Binding Protein-Like (Spl) Genes In Arabidopsis Thaliana, Mingli Xu, Tieqiang Hu, Jianfei Zhao, Mee-Yeon Park, Keith W. Earley, Gang Wu, Li Yang, R. Scott Poethig

Faculty Publications

Correct developmental timing is essential for plant fitness and reproductive success. Two important transitions in shoot development—the juvenile-to-adult vegetative transition and the vegetative-to-reproductive transition—are mediated by a group of genes targeted by miR156, SQUAMOSA PROMOTER BINDING PROTEIN (SBP) genes. To determine the developmental functions of these genes in Arabidopsis thaliana, we characterized their expression patterns, and their gain-of-function and loss-of-function phenotypes. Our results reveal that SBP-LIKE (SPL) genes in Arabidopsis can be divided into three functionally distinct groups: 1) SPL2, SPL9, SPL10, SPL11, SPL13 and SPL15 contribute to both the juvenile-to-adult vegetative transition …

Structural Characterization Of Tick Cement Cones Collected From In Vivo And Artifical Membrane Blood-Fed Lone Star Ticks (Ambylomma Americanum), Rebekah Bullard, Paige Allen, Chien-Chung Chao, Jessica Douglas, Pradipta K. Das, Sarah E. Morgan, Wei-Mei Ching, Shahid Karim

Faculty Publications

The Lone Star tick, Amblyomma americanum, is endemic to the southeastern United States and capable of transmitting pathogenic diseases and causing non-pathogenic conditions. To remain firmly attached to the host, the tick secretes a proteinaceous matrix termed the cement cone which hardens around the tick’s mouthparts to assist in the attachment of the tick as well as to protect the mouthparts from the host immune system. Cement cones collected from ticks on a host are commonly contaminated with host skin and hair making analysis of the cone difficult. To reduce the contamination found in the cement cone, we have adapted …

Sources And Transformations Of Dissolved Lignin Phenols And Chromophoric Dissolved Organic Matter In Otsuchi Bay, Japan, Chia-Jung Lu, Ronald Benner, Cedric Fichot, Hideki Fukuda, Youhei Yamashita, Hiroshi Ogawa

Faculty Publications

Dissolved lignin phenols and optical properties of dissolved organic matter (DOM) were measured to investigate the sources and transformations of terrigenous DOM (tDOM) in Otsuchi Bay, Japan. Three rivers discharge into the bay, and relatively high values of syringyl:vanillyl phenols (0.73 ± 0.07) and cinnamyl:vanillyl phenols (0.33 ± 0.10) indicated large contributions of non-woody angiosperm tissues to lignin and tDOM. The physical mixing of river and seawater played an important role in controlling the concentrations and distributions of lignin phenols and chromophoric DOM (CDOM) optical properties in the bay. Lignin phenol concentrations and the CDOM absorption coefficient at 350 nm, …

Assessment Of Tick Antioxidant Responses To Exogenous Oxidative Stressors And Insight Into The Role Of Catalase In The Reproductive Fitness Of The Gulf Coast Tick, Amblyomma Maculatum, D. Kumar, K. Budachetri, V.C. Meyers, Shahid Karim

Faculty Publications

As obligate blood‐sucking ectoparasites, to avoid tissue damage, ticks must neutralize the reactive oxygen species (ROS) generated from uptake and digestion of a bloodmeal. Consequently, ticks utilize a battery of antioxidant molecules, including catalase (CAT), an enzyme that converts hydrogen peroxide (H₂O₂) into water and oxygen. Here, we investigated the tick antioxidant machinery by exogenous injection of sublethal doses of H₂O₂ or paraquat. The relative transcript levels of selected Amblyomma maculatum antioxidant targets in tissues were determined by quantitative reverse transcriptase PCR following treatment. The results showed 2–16‐fold increases in target antioxidant gene …

Rickettsia Parkeri Colonization In Ambylomma Maculatum: The Role Of Superoxide Dismutases, Gary Crispell, Khemraj Budachetri, Shahid Karim

Faculty Publications

Background

The Gulf Coast tick (Amblyomma maculatum) is an arthropod vector of Rickettsia parkeri, the causative agent of American boutonneuse fever and an infectious agent of public health significance. In this study, we evaluated the biological significance of the superoxide dismutases (SODs) of A. maculatum in hematophagy and R. parkeri colonization within the tick host.

Methods

An RNA interference approach was used to measure the functional roles of tick SODs (Cu/Zn-SOD and Mn-SOD) in R. parkeri colonization of the tick vector. Total microbial load, R. parkeri infection rate, and compensatory mechanisms by tick genes were …

Destruction Of Opportunistic Pathogens Via Polymer Nanoparticle-Mediated Release Of Plant-Based Antimicrobial Payloads, Dahlia N. Amato, Douglas V. Amato, Olga V. Mavrodi, Dwaine A. Braasch, Susan E. Walley, Jessica R. Douglas, Dmitri V. Mavrodi, Derek L. Patton

Faculty Publications

The synthesis of antimicrobial thymol/carvacrol‐loaded polythioether nanoparticles (NPs) via a one‐pot, solvent‐free miniemulsion thiol‐ene photopolymerization process is reported. The active antimicrobial agents, thymol and carvacrol, are employed as “solvents” for the thiol‐ene monomer phase in the miniemulsion to enable facile high capacity loading (≈50% w/w), excellent encapsulation efficiencies (>95%), and elimination of all postpolymerization purification processes. The NPs serve as high capacity reservoirs for slow‐release and delivery of thymol/carvacrol‐combination payloads that exhibit inhibitory and bactericidal activity (>99.9% kill efficiency at 24 h) against gram‐positive and gram‐negative bacteria, including both saprophytic (Bacillus subtilis ATCC 6633 and Escherichia coli …

The Removal Kinetics Of Dissolved Organic Matter And The Optical Clarity Of Groundwater, Francis H. Chapelle, Yuan Shen, Eric W. Strom, Ronald Benner

Faculty Publications

Concentrations of dissolved organic matter (DOM) and ultraviolet/visible light absorbance decrease systematically as groundwater moves through the unsaturated zones overlying aquifers and along flowpaths within aquifers. These changes occur over distances of tens of meters (m) implying rapid removal kinetics of the chromophoric DOM that imparts color to groundwater. A one-compartment input-output model was used to derive a differential equation describing the removal of DOM from the dissolved phase due to the combined effects of biodegradation and sorption. The general solution to the equation was parameterized using a 2-year record of dissolved organic carbon (DOC) concentration changes in groundwater at …

Does Habitat Restoration Increase Coexistence Of Native Stream Fishes With Introduced Brown Trout: A Case Study On The Middle Provo River, Utah, Usa, Mark C. Belk, Eric J. Billman, Craig Ellsworth, Brock R. Mcmillan

Faculty Publications

Restoration of altered or degraded habitats is often a key component in the conservation plan of native aquatic species, but introduced species may influence the response of the native community to restoration. Recent habitat restoration of the middle section of the Provo River in central Utah, USA, provided an opportunity to evaluate the effect of habitat restoration on the native fish community in a system with an introduced, dominant predator—brown trout (Salmo trutta). To determine the change in distribution of fish species and community composition, we surveyed 200 m of each of the four study reaches both before …

Predicting Dissolved Lignin Phenol Concentrations In The Coastal Ocean From Chromophoric Dissolved Organic Matter (Cdom) Absorption Coefficients, Cédric G. Fichot, Ronald Benner, Karl Kaiser, Yuan Shen, Rainer M. W. Amon, Hiroshi Ogawa, Chua-Jung Lu

Faculty Publications

Dissolved lignin is a well-established biomarker of terrigenous dissolved organic matter (DOM) in the ocean, and a chromophoric component of DOM. Although evidence suggests there is a strong linkage between lignin concentrations and chromophoric dissolved organic matter (CDOM) absorption coefficients in coastal waters, the characteristics of this linkage and the existence of a relationship that is applicable across coastal oceans remain unclear. Here, 421 paired measurements of dissolved lignin concentrations (sum of nine lignin phenols) and CDOM absorption coefficients [ag(λ)] were used to examine their relationship along the river-ocean continuum (0–37 salinity) and across contrasting coastal oceans (sub-tropical, temperate, high-latitude). …

Costs Of Resistance And Infection By A Generalist Pathogen, Tad Dallas, Mathieu Holtackers, John M. Drake

Faculty Publications

Pathogen infection is typically costly to hosts, resulting in reduced fitness. However, pathogen exposure may also come at a cost even if the host does not become infected. These fitness reductions, referred to as “resistance costs”, are inducible physiological costs expressed as a result of a trade-off between resistance to a pathogen and aspects of host fitness (e.g., reproduction). Here, we examine resistance and infection costs of a generalist fungal pathogen (Metschnikowia bicuspidata) capable of infecting a number of host species. Costs were quantified as reductions in host lifespan, total reproduction, and mean clutch size as a function …