Life Sciences Commons^™

Multiple Environmental Stressors Induce Complex Transcriptomic Responses Indicative Of Phenotypic Outcomes In Western Fence Lizard, Kurt A. Gust, Vijender Chaitankar, Preetam Ghosh, Mitchell S. Wilbanks, Xianfeng Chen, Natalie D. Barker, Don Pham, Leona D. Scanlan, Arun Rawat, Larry G. Talent, Michael J. Quinn Jr., Christopher D. Vulpe, Mohamed O. Elasri, Mark S. Johnson, Edward J. Perkins, Craig A. Mcfarland

Faculty Publications

Background

The health and resilience of species in natural environments is increasingly challenged by complex anthropogenic stressor combinations including climate change, habitat encroachment, and chemical contamination. To better understand impacts of these stressors we examined the individual- and combined-stressor impacts of malaria infection, food limitation, and 2,4,6-trinitrotoluene (TNT) exposures on gene expression in livers of Western fence lizards (WFL, Sceloporus occidentalis) using custom WFL transcriptome-based microarrays.

Results

Computational analysis including annotation enrichment and correlation analysis identified putative functional mechanisms linking transcript expression and toxicological phenotypes. TNT exposure increased transcript expression for genes involved in erythropoiesis, potentially in response to …

Remote Sensing Of Sargassum Biomass, Nutrients, And Pigments, Mengqiu Wang, Chuanmin Hu, Jennifer Cannizzaro, David English, Xingxing Han, David Naar, Brian Lapointe, Rachel Brewton, Frank J. Hernandez Jr.

Faculty Publications

ield and laboratory experiments are designed to measure Sargassum biomass per area (density), surface reflectance, nutrient contents, and pigment concentrations. An Alternative Floating Algae Index (AFAI)‐biomass density model is established to link the spectral reflectance to Sargassum biomass density, with a relative uncertainty of ~ 12%. Monthly mean integrated Sargassum biomass in the Caribbean Sea and Central West Atlantic reached at least 4.4 million tons in July 2015. The average % C, % N, and % P per dry‐weight are 27.16, 1.06, and 0.10, respectively. The mean chlorophyll‐a (Chl‐a) concentration is ~ 0.05% of the dry‐weight. With these parameters, the …

Carboxypeptidase O Is A Lipid Droplet-Associated Enzyme Able To Cleave Both Acidic And Polar C-Terminal Amino Acids, Linnea C. Burke, Hazel O. Ezeribe, Anna Y. Kwon, Donnell Dockery, Peter J. Lyons

Faculty Publications

Carboxypeptidase O (CPO) is a member of the M14 family of metallocarboxypeptidases with a preference for the cleavage of C-terminal acidic amino acids. CPO is largely expressed in the small intestine, although it has been detected in other tissues such as the brain and ovaries. CPO does not contain a prodomain, nor is it strongly regulated by pH, and hence appears to exist as a constitutively active enzyme. The goal of this study was to investigate the intracellular distribution and activity of CPO in order to predict physiological substrates and function. The distribution of CPO, when expressed in MDCK cells, …

Evidence That A Respiratory Shield In Escherichia Coli Protects A Low-Molecular-Mass Fe-Ii Pool From O2-Dependent Oxidation, Joshua D. Wofford, Naimah Bolaji, Nathaniel Dziuba, Franklin Wayne Outten, Paul A. Lindahl

Faculty Publications

Iron is critical for virtually all organisms, yet major questions remain regarding the systems' level understanding of iron in whole cells. Here, we obtained Mössbauer and EPR spectra of Escherichia coli cells prepared under different nutrient iron concentrations, carbon sources, growth phases, and O₂ concentrations to better understand their global iron content. We investigated wild-type cells and those lacking Fur, FtnA, Bfr, and Dps proteins. The coarse-grain iron content of exponentially growing cells consisted of iron-sulfur clusters, variable amounts of nonheme high-spin Fe^II species, and an unassigned residual quadrupole doublet. The iron in stationary-phase cells was dominated by …

Detrital Nutrient Content And Leaf Species Differenitally Affect Growth And Nutritional Regulation Of Detritivores, Halvor M. Halvorson, Chris L. Fuller, Sally A. Entrekin, J. Thad Scott, Michelle A. Evans-White

Faculty Publications

© 2018 The Authors Resource nutrient content and identity are common bottom–up controls on organismal growth and nutritional regulation. One framework to study these factors, ecological stoichiometry theory, predicts that elevated resource nitrogen (N) and phosphorus (P) contents enhance organism growth by alleviating constraints on N and P acquisition. However, the regulatory mechanisms underlying this response – including whether responses depend on resource identity – remain poorly understood. In this study, we tested roles of detrital N and P contents and identity (leaf species) in constraining growth of aquatic invertebrate detritivores. We synthesized results from seven detritivore species fed wide …

The Tick Endosymbiont Candidatus Midichloria Mitochondrii And Selenoproteins Are Essential For The Growth Of Rickettsia Parkeri In The Gulf Coast Tick Vector, Khemraj Budachetri, Deepak Kumar, Gary Crispell, Christine Beck, Gregory Dasch, Shahid Karim

Faculty Publications

Background

Pathogen colonization inside tick tissues is a significant aspect of the overall competence of a vector. Amblyomma maculatum is a competent vector of the spotted fever group rickettsiae, Rickettsia parkeri. When R. parkeri colonizes its tick host, it has the opportunity to dynamically interact with not just its host but with the endosymbionts living within it, and this enables it to modulate the tick’s defenses by regulating tick gene expression. The microbiome in A. maculatum is dominated by two endosymbiont microbes: a Francisella-like endosymbiont (FLE) and CandidatusMidichloria mitochondrii (CMM). A range of selenium-containing proteins (selenoproteins) in A. …

Evolving Paradigms In Biological Carbon Cycling In The Ocean, Chuanlun Zhang, Hongyue Dang, Farooq Azam, Ronald Benner, Louis Legendre, Uta Passow, Luca Polimene, Carol Robinson, Curtis A. Suttle, Nianzhi Jiao

Faculty Publications

Carbon is a keystone element in global biogeochemical cycles. It plays a fundamental role in biotic and abiotic processes in the ocean, which intertwine to mediate the chemistry and redox status of carbon in the ocean and the atmosphere. The interactions between abiotic and biogenic carbon (e.g. CO₂, CaCO₃, organic matter) in the ocean are complex, and there is a half-century-old enigma about the existence of a huge reservoir of recalcitrant dissolved organic carbon (RDOC) that equates to the magnitude of the pool of atmospheric CO₂. The concepts of the biological carbon pump (BCP) …

Detection And Verification Of Mammalian Mirtrons By Northern Blotting, Mohammad Farid Zia, Alex S. Flynt

Faculty Publications

microRNAs (miRNAs) have vital roles in regulating gene expression—contributing to major diseases like cancer and heart disease. Over the last decade, thousands of miRNAs have been discovered through high throughput sequencing-based annotation. Different classes have been described, as well as a great dynamic range of expression levels. While sequencing approaches provide insight into biogenesis and allow confident identification, there is a need for additional methods for validation and characterization. Northern blotting was one of the first techniques used for studying miRNAs, and remains one of the most valuable as it avoids enzymatic manipulation of miRNA transcripts. Blotting can also provide …

Physical Processes Dictate Early Biogeochemical Dynamics Of Soil Pyrogenic Organic Matter In A Subtropical Forest Ecosystem, Jason Stuart, Russell Anderson, Patrick Lazzarino, Kevin A. Kuehn, Omar R. Harvey

Faculty Publications

Quantifying links between pyOM dynamics, environmental factors and processes is central to predicting ecosystem function and response to future perturbations. In this study, changes in carbon (TC), nitrogen (TN), pH, and relative recalcitrance (R50) for pineand cordgrass-derived pyOM were measured at 3–6 weeks intervals throughout the first year of burial in the soil. Objectives were to (1) identify key environmental factors and processes driving early-stage pyOM dynamics, and (2) develop quantitative relationships between environmental factors and observed changes in pyOM properties. The study was conducted in sandy soils of a forested ecosystem within the Longleaf pine range of the United …

Threshold-Dependent Repression Of Spl Gene Expression By Mir156/Mir157 Controls Vegetative Phase Change In Arabidopsis Thaliana, Jia He, Mingli Xu, Matthew R. Willmann, Kevin Mccormick, Tieqiang Hu, Li Yang, Colby G. Starker, Daniel F. Voytas, Blake C. Meyers, R. Scott Poethig

Faculty Publications

Vegetative phase change is regulated by a decrease in the abundance of the miRNAs, miR156 and miR157, and the resulting increase in the expression of their targets, SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) transcription factors. To determine how miR156/miR157 specify the quantitative and qualitative changes in leaf morphology that occur during vegetative phase change, we measured their abundance in successive leaves and characterized the phenotype of mutations in different MIR156 and MIR157 genes. miR156/miR157 decline rapidly between leaf 1&2 and leaf 3 and decrease more slowly after this point. The amount of miR156/miR157 in leaves 1&2 greatly exceeds the …

High Male Sexual Investment As A Driver Of Extinction In Fossil Ostracods, Maria João Fernandes Martins, T. Markham Puckett, Rowan Lockwood, John P. Swaddle, Gene Hunt

Faculty Publications

Sexual selection favours traits that confer advantages in the competition for mates. In many cases, such traits are costly to produce and maintain, because the costs help to enforce the honesty of these signals and cues. Some evolutionary models predict that sexual selection also produces costs at the population level, which could limit the ability of populations to adapt to changing conditions and thus increase the risk of extinction. Other models, however, suggest that sexual selection should increase rates of adaptation and enhance the removal of deleterious mutations, thus protecting populations against extinction. Resolving the conflict between these models is …

A Plant-Produced Vaccine Protects Mice Against Lethal West Nile Virus Infection Without Enhancing Zika Or Dengue Virus Infectivity, Huafang Lai, Amber M. Paul, Haiyan Sun, Junyun He, Ming Yang, Fengwei Bai

Faculty Publications

West Nile virus (WNV) has caused multiple global outbreaks with increased frequency of neuroinvasive disease in recent years. Despite many years of research, there are no licensed therapeutics or vaccines available for human use. One of the major impediments of vaccine development against WNV is the potential enhancement of infection by related flaviviruses in vaccinated subjects through the mechanism of antibody-dependent enhancement of infection (ADE). For instance, the recent finding of enhancement of Zika virus (ZIKV) infection by pre-exposure to WNV further complicates the development of WNV vaccines. Epidemics of WNV and the potential risk of ADE by current vaccine …

Long-Term Irrigation Affects The Dynamics And Activity Of The Wheat Rhizosphere Microbiome, Dmitri V. Mavrodi, Olga Mavrodi, Liam D.H. Elbourne, Sasha Tetu, Robert F. Bonsall, James Parejko, Mingming Yang, Ian T. Paulsen, David M. Weller, Linda S. Thomashow

Faculty Publications

The Inland Pacific Northwest (IPNW) encompasses 1. 6 million cropland hectares and is a major wheat-producing area in the western United States. The climate throughout the region is semi-arid, making the availability of water a significant challenge for IPNW agriculture. Much attention has been given to uncovering the effects of water stress on the physiology of wheat and the dynamics of its soilborne diseases. In contrast, the impact of soil moisture on the establishment and activity of microbial communities in the rhizosphere of dryland wheat remains poorly understood. We addressed this gap by conducting a three-year field study involving wheat …

Does Body Size Affect Fitness The Same Way In Males And Females? A Test Of Multiple Fitness Components, Ashlee N. Smith, Mark C. Belk

Faculty Publications

Body size generally has an important relationship with fitness, whereby larger body size leads to an increase in fitness through competition, reproductive output and survivorship. However, the traits through which body size increases fitness often differ between the sexes. We tested for the effects of body size on fitness in both sexes using three separate experiments on competitive ability, reproductive output and starvation resistance in the burying beetle Nicrophorus marginatus. Results varied between sexes as follows: (1) larger body size increased competitive ability differentially between sexes; (2) female body size, but not male body size, significantly affected reproductive output …

Spatial Extinction Date Estimation: A Novel Method For Reconstructing Spatiotemporal Patterns Of Extinction And Identifying Potential Zones Of Rediscovery, Colin J. Carlson, Kevin R. Burgio, Tad Dallas, Alexander L. Bond

Faculty Publications

1. The estimation of extinction dates from limited and incomplete sighting records

is a key challenge in conservation (when experts are uncertain whether a species has

gone extinct) and historical ecology (when the date and mechanism of extinction is

controversial).

2. We introduce a spatially-explicit method of interpolating extinction date estima8 tors, allowing users to estimate spatiotemporal surfaces of population persistence 9 from georeferenced sighting data of variable quality.

3. We present the R package spatExtinct, which produces spatially-explicit extinction date surfaces from geolocated sightings, including options for custom randomization schemes to improve accuracy with limited datasets. We use simulations …

A Bio-Based Pro-Antimicrobial Polymer Network Via Degradable Acetal Linkages, Douglas V. Amato, Dahlia N. Amato, Logan T. Blancett, Olga V. Mavrodi, William B. Martin, Sarah N. Swilley, Michael J. Sandoz, Glenmore Shearer, Dmitri V. Mavrodi, Derek Patton

Faculty Publications

The synthesis of a fully degradable, bio-based, sustained release, pro-antimicrobial polymer network comprised of degradable acetals (PANDA) is reported. The active antimicrobial agent – p-anisaldehyde (pA) (an extract from star anise) – was converted into a UV curable acetal containing pro-antimicrobial monomer and subsequently photopolymerized into a homogenous thiol-ene network. Under neutral to acidic conditions (pH < 8), the PANDAs undergo surface erosion and exhibit sustained release of pA over 38 days. The release of pA from PANDAs was shown to be effective against both bacterial and fungal pathogens. From a combination of confocal microscopy and transmission electron microscopy, we observed that the released pA disrupts the cell membrane. Additionally, we demonstrated that PANDAs have minimal cytotoxicity towards both epithelial cells and macrophages. Although a model platform, these results point to promising pathways for the design of fully degradable sustained-release antimicrobial systems with potential applications in agriculture, pharmaceuticals, cosmetics, household/personal care, and food industries.

Rewired Rnai-Mediated Genome Surveillance In House Dust Mites, Mosharrof H. Mondal, Pavel Klimov, Alex S. Flynt

Faculty Publications

House dust mites are common pests with an unusual evolutionary history, being descendants of a parasitic ancestor. Transition to parasitism is frequently accompanied by genome rearrangements, possibly to accommodate the genetic change needed to access new ecology. Transposable element (TE) activity is a source of genomic instability that can trigger large-scale genomic alterations. Eukaryotes have multiple transposon control mechanisms, one of which is RNA interference (RNAi). Investigation of the dust mite genome failed to identify a major RNAi pathway: the Piwi-associated RNA (piRNA) pathway, which has been replaced by a novel small-interfering RNA (siRNA)-like pathway. Co-opting of piRNA function by …

Experimental Evidence Of A Pathogen Invasion Threshold, Tad Dallas, Martin Krkošek, John M. Drake

Faculty Publications

Host density thresholds to pathogen invasion separate regions of parameter space corresponding to endemic and disease-free states. The host density threshold is a central concept in theoretical epidemiology and a common target of human and wildlife disease control programmes, but there is mixed evidence supporting the existence of thresholds, especially in wildlife populations or for pathogens with complex transmission modes (e.g. environmental transmission). Here, we demonstrate the existence of a host density threshold for an environmentally transmitted pathogen by combining an epidemiological model with a microcosm experiment. Experimental epidemics consisted of replicate populations of naive crustacean zooplankton (Daphnia dentifera …

Exosomes Serve As Novel Modes Of Tick-Borne Flavivirus Transmission From Arthropod To Human Cells And Facilitates Dissemination Of Viral Rna And Proteins To The Vertebrate Neuronal Cells, Wenshuo Zhou, Michael Woodson, Biswas Neupane, Fengwei Bai, Michael B. Sherman, Kyung H. Choi, Girish Neelakanta, Hameeda Sultana

Faculty Publications

Molecular determinants and mechanisms of arthropod-borne flavivirus transmission to the vertebrate host are poorly understood. In this study, we show for the first time that a cell line from medically important arthropods, such as ticks, secretes extracellular vesicles (EVs) including exosomes that mediate transmission of flavivirus RNA and proteins to the human cells. Our study shows that tick-borne Langat virus (LGTV), a model pathogen closely related to tick-borne encephalitis virus (TBEV), profusely uses arthropod exosomes for transmission of viral RNA and proteins to the human- skin keratinocytes and blood endothelial cells. Cryo-electron microscopy showed the presence of purified arthropod/neuronal exosomes …

De-Extinction And The Conception Of Species, Leonard Finkelman

Faculty Publications

Developments in genetic engineering may soon allow biologists to clone organisms from extinct species. The process, dubbed “de-extinction,” has been publicized as a means to bring extinct species back to life. For theorists and philosophers of biology, the process also suggests a thought experiment for the ongoing “species problem”: given a species concept, would a clone be classified in the extinct species? Previous analyses have answered this question in the context of specific de-extinction technologies or particular species concepts. The thought experiment is given more comprehensive treatment here. Given the products of three de-extinction technologies, twenty-two species concepts are “tested” …

Modeling The Disappearance Of The Neanderthals Using Concepts Of Population Dynamics And Ecology, Michael F. Roberts, Stephen E. Bricher

Faculty Publications

Current hypotheses regarding the disappearance of Neanderthals (NEA) in Europe fall into two main categories: climate change, and competition. Here we review current research and existing mathematical models that deal with this question, and we propose an approach that incorporates and permits the investigation of the current hypotheses. We have developed a set of differential equations that model population dynamics of anatomically modern humans (AMH) and NEA, their ecological relations to prey species, and their mutual interactions. The model allows investigators to explore each of the two main categories or combinations of both, as well as various forms of competition …

The Roles Of Inter- And Intra-Sexual Selection In Behavioral Isolation Between Native And Invasive Pupfishes, Cory Becher, Jennifer M. Gumm

Faculty Publications

Male-male competition and female mate choice may both play important roles in driving and maintaining reproductive isolation between species. When previously allopatric species come into secondary contact with each other due to introductions, they provide an opportunity to evaluate the identity and strength of reproductive isolating mechanisms. If reproductive isolation is not maintained, hybridization may occur. We examined how reproductive isolating mechanisms mediate hybridization between endemic populations of the Red River pupfish Cyprinodon rubrofluviatilis and the recently introduced sheepshead minnow C. variegatus. In lab-based dominance trials, males of both species won the same number of competitions. However, male C. rubrofluviatilis …

The Effects Of Ultraviolet Light On Anthocyanin Accumulation In The Adventitious Roots Of Sedum Wrightii (Crassulaceae), Lila D. Kerr, Dennis A. Gravatt, Robert J. Wiggers

Faculty Publications

Several studies have supported the idea that anthocyanin accumulation may be a possible protection mechanism in plants against DNA damage caused by ultraviolet radiation (UV). This study explored the accumulation of anthocyanins in the adventitious root tips of Sedum wrightii using the following treatments: UVA, UVA+low UVB, and UVA+high UVB. Following exposure to UV radiation, samples were analyzed for anthocyanin accumulation using an ethanol extraction procedure. Using ELISA, additional root samples were analyzed for indicators of DNA damage: cyclobutane pyrimidine dimers (CPDs) and pyrimidine (6-4) pyrimidone dimers (6-4 PPs). The anthocyanin concentrations were significantly higher in the UVA + high …

Effects Of Nonnative Rainbow Trout On Two Species Of Endemic Mexican Amphibians, A. B. Estrella Zamora, Geoffrey R. Smith, J. A. Lemos-Espinal, G. A. Woolrich-Pina, R. Montoya Ayala

Faculty Publications

No abstract provided.

Amphibians And Reptiles Of The State Of Durango, Mexico, With Comparisons With Adjoining States, J. A. Lemos-Espinal, Geoffrey R. Smith, H. Gadsden-Esparza, R. Valdez-Lares, G. A. Woolrich-Pina

Faculty Publications

No abstract provided.

Amphibians And Reptiles Of The State Of San Luis Potosi, Mexico, With Comparisons With Adjoining States, J. A. Lemos-Espinal, Geoffrey R. Smith, G. A. Woolrich-Pina

Faculty Publications

No abstract provided.