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Full-Text Articles in Life Sciences

Biophysical Characteristics Of Lipid-Induced Aβ Oligomers Correlate To Distinctive Phenotypes In Transgenic Mice, Jhinuk Saha, Dexter N. Dean, Shailendra Dhakal, Kelli A. Stockmal, Sarah E. Morgan, Kristy D. Dillon, Munir F. Adamo, Yona Levites, Vijayaraghavan Rangachari Feb 2021

Biophysical Characteristics Of Lipid-Induced Aβ Oligomers Correlate To Distinctive Phenotypes In Transgenic Mice, Jhinuk Saha, Dexter N. Dean, Shailendra Dhakal, Kelli A. Stockmal, Sarah E. Morgan, Kristy D. Dillon, Munir F. Adamo, Yona Levites, Vijayaraghavan Rangachari

Faculty Publications

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that affects cognition and memory. Recent advances have helped identify many clinical sub-types in AD. Mounting evidence point toward structural polymorphism among fibrillar aggregates of amyloid-β (Aβ) to being responsible for the phenotypes and clinical manifestations. In the emerging paradigm of polymorphism and prion-like propagation of aggregates in AD, the role of low molecular weight soluble oligomers, which are long known to be the primary toxic agents, in effecting phenotypes remains inconspicuous. In this study, we present the characterization of three soluble oligomers of Aβ42, namely 14LPOs, 16LPOs, and GM1Os with discreet …


Associative Nitrogen Fixation Linked With Three Perennial Bioenergy Grasses In Field And Greenhouse Experiments, Jayani J. Wewalwela, Yuan Tian, Janet R. Donaldson, Brian S. Baldwin, Jac J. Varco, Brett Rushing, Haoliang Lu, Mark A. Williams Dec 2020

Associative Nitrogen Fixation Linked With Three Perennial Bioenergy Grasses In Field And Greenhouse Experiments, Jayani J. Wewalwela, Yuan Tian, Janet R. Donaldson, Brian S. Baldwin, Jac J. Varco, Brett Rushing, Haoliang Lu, Mark A. Williams

Faculty Publications

© 2020 The Authors. Associative nitrogen (N2)‐fixation (ANF) by bacteria in the root‐zone of perennial bioenergy grasses has the potential to replace or supplement N fertilizer and support sustainable production of biomass, but its application in marginal ecosystems requires further evaluation. In this study, we first combined both greenhouse and field experiments, to explore the N2 fixation effects of three temperate feedstocks Miscanthus × giganteus (giant miscanthus, Freedom), Panicum virgatum (switchgrass, Alamo), and Saccharum sp. (energycane, Ho 02‐147). In field studies across three growing seasons, plant and soil pools of candidate feedstocks were partially composed of N …


Quantifying Species Traits Related To Oviposition Behavior And Offspring Survival In Two Important Disease Vectors, Donald A. Yee, William C. Glasgow, Nnaemeka F. Ezeakacha Sep 2020

Quantifying Species Traits Related To Oviposition Behavior And Offspring Survival In Two Important Disease Vectors, Donald A. Yee, William C. Glasgow, Nnaemeka F. Ezeakacha

Faculty Publications

Animals with complex life cycles have traits related to oviposition and juvenile survival that can respond to environmental factors in similar or dissimilar ways. We examined the preference-performance hypothesis (PPH), which states that females lacking parental care select juvenile habitats that maximize fitness, for two ubiquitous mosquito species, Aedes albopictus and Culex quinquefasciatus. Specifically, we examined if environmental factors known to affect larval abundance patterns in the field played a role in the PPH for these species. We first identified important environmental factors from a field survey that predicted larvae across different spatial scales. We then performed two experiments, …


Discovery Of Exosomes From Tick Saliva And Salivary Glands Reveals Therapeutic Roles For Cxcl12 And Il-8 In Wound Healing At The Tick–Human Skin Interface, Wenshuo Zhou, Faizan Tahir, Joseph Che Yen Wang, Michael Woodson, Michael B. Sherman, Shahid Karim, Girish Neelakanta, Hameeda Sultana Jul 2020

Discovery Of Exosomes From Tick Saliva And Salivary Glands Reveals Therapeutic Roles For Cxcl12 And Il-8 In Wound Healing At The Tick–Human Skin Interface, Wenshuo Zhou, Faizan Tahir, Joseph Che Yen Wang, Michael Woodson, Michael B. Sherman, Shahid Karim, Girish Neelakanta, Hameeda Sultana

Faculty Publications

© Copyright © 2020 Zhou, Tahir, Wang, Woodson, Sherman, Karim, Neelakanta and Sultana.Ticks secrete various anti-coagulatory, anti-vasoconstrictory, anti-inflammatory, and anti-platelet aggregation factors in their saliva at the bite site during feeding to evade host immunological surveillance and responses. For the first time, we report successful isolation of exosomes (small membrane-bound extracellular signaling vesicles) from saliva and salivary glands of partially fed or unfed ixodid ticks. Our data showed a novel role of these in vivo exosomes in the inhibition of wound healing via downregulation of C-X-C motif chemokine ligand 12 (CXCL12) and upregulation of interleukin-8 (IL-8). Cryo-electron microscopy (cryo-EM) analysis …


Light And Temperature Mediate Algal Simulation Of Heterotrophic Activity On Decomposing Leaf Litter, Cody A. Pope, Halvor M. Halvorson, Robert H. Findlay, Steven N. Francoeur, Kevin A. Kuehn Jul 2020

Light And Temperature Mediate Algal Simulation Of Heterotrophic Activity On Decomposing Leaf Litter, Cody A. Pope, Halvor M. Halvorson, Robert H. Findlay, Steven N. Francoeur, Kevin A. Kuehn

Faculty Publications

  1. Recent evidence suggests that periphytic algae stimulate plant litter heterotrophs (fungi and bacteria) in the presence of light, but few studies have tested whether this stimulation varies across gradients of light, which may covary with temperature.
  2. We exposed field‐conditioned Typha domingensis litter to fully‐crossed, short‐term gradients of temperature (15, 20, 25, and 30°C) and light (0, 25, 53, 123, and 388 µmol quanta m−2 s−1) and measured responses of litter‐associated algal, fungal, and bacterial production rates and β‐glucosidase, β‐xylosidase, and phenol oxidase enzyme activities in the laboratory.
  3. Increased light stimulated algal production rates, from immeasurable production under …


Escherichia Coli Antimicrobial Resistance Variability In Water Runoff And Soil From A Remnant Native Prairie, And Improved Pasture, And A Cultivated Agricultural Watershed, Maitreyee Mukherjee, Terry Gentry, Heidi Mjelde, John P. Brooks, Daren Harmel, Lucas Gregory, Kevin Wagner Apr 2020

Escherichia Coli Antimicrobial Resistance Variability In Water Runoff And Soil From A Remnant Native Prairie, And Improved Pasture, And A Cultivated Agricultural Watershed, Maitreyee Mukherjee, Terry Gentry, Heidi Mjelde, John P. Brooks, Daren Harmel, Lucas Gregory, Kevin Wagner

Faculty Publications

Although many previous studies have examined patterns of antimicrobial resistance (AMR) and multidrug resistance (MDR) from domestic animals and farm environments, comparatively little is known about the environmental sources and natural reservoirs of AMR and MDR. In this study, we collected stormwater runoff and soil samples from three watersheds in Texas. Escherichia coli (E. coli) were enumerated, isolated, and analyzed for resistance patterns. E. coli from all sites, irrespective of land use, displayed the presence of AMR/MDR. Higher levels of AMR/MDR were observed in water compared to soil. More isolates were resistant to cephalothin than other antibiotics. For …


Late Pleistocene Range Expansion Of North American Topminnows Accompanied By Admixture And Introgression, David D. Duvernell, Eric Westhafer, Jacob F. Schaefer Sep 2019

Late Pleistocene Range Expansion Of North American Topminnows Accompanied By Admixture And Introgression, David D. Duvernell, Eric Westhafer, Jacob F. Schaefer

Faculty Publications

Aim: We used genome‐scale sampling to assess the phylogeography of a group of topminnows in the Fundulus notatus species complex. Two of the species have undergone extensive range expansions resulting in broadly overlapping distributions, and sympatry within drainages has provided opportunities for hybridization and introgression. We assessed the timing and pattern of range expansion in the context of late Pleistocene–Holocene drainage events and evaluated the evidence for introgressive hybridization between species.

Location: Central and southern United States including drainages of the Gulf of Mexico Coastal Plain and portions of the Mississippi River drainage in and around the Central …


Scale Dependence Of Sex-Specific Movement In A Small-Bodied Stream Fish, Scott R. Clark, Brian R. Kreiser, Jacob F. Schraefer, Laura K. Stewart Jul 2019

Scale Dependence Of Sex-Specific Movement In A Small-Bodied Stream Fish, Scott R. Clark, Brian R. Kreiser, Jacob F. Schraefer, Laura K. Stewart

Faculty Publications

  1. Animal movement at localised scales is often modulated by competing pressures such as avoiding predators while acquiring resources and mates. The relative magnitude of these trade‐offs may affect males and females differently, often resulting in sex‐specific differences in movement.
  2. Sex‐biases in movement have been linked to mating systems (e.g. monogamy or polygamy) in birds and mammals; however, this relationship has received less attention among fishes. Using passive integrated transponder tags and a series of stationary antennas, we evaluated the movement dynamics of a small‐bodied, sexually dimorphic stream fish Fundulus olivaceus over a 30‐day period in a fourth‐order tributary to the …


Preliminary Investigation Of A Diverse Megafossil Floral Assemblage From The Middle Miocene Of Southern Mississippi, Usa, Daniel M. Mcnair, Debra Z. Stults, Brian Axsmith, Mac H. Alford, James E. Starnes Jul 2019

Preliminary Investigation Of A Diverse Megafossil Floral Assemblage From The Middle Miocene Of Southern Mississippi, Usa, Daniel M. Mcnair, Debra Z. Stults, Brian Axsmith, Mac H. Alford, James E. Starnes

Faculty Publications

Our understanding of Miocene floras in eastern North America is hampered by the rarity of megafossil sites. An early report from the middle Miocene Hattiesburg Formation in Mississippi included palms and Ulmus. A later report listed Taxodium, Salix, either Morus or Celtis, and monocot fragments. The floral assemblage described here was recently recovered from along the Bouie River in southern Mississippi. Ferns are represented by complete Salvinia specimens including attached sporocarps, Woodwardia, and Osmunda. Conifers are represented by branchlets of Taxodium. Angiosperms include leaves attributable to the Lauraceae. Platanus is known from leaves, stipules, and fruits. …


Linking Nutrient Stoichiometry To Zika Virus Transmission In A Mosquito, Andrew S. Paige, Shawna K. Bellamy, Barry W. Alto, Catherine L. Dean, Donald A. Yee Jun 2019

Linking Nutrient Stoichiometry To Zika Virus Transmission In A Mosquito, Andrew S. Paige, Shawna K. Bellamy, Barry W. Alto, Catherine L. Dean, Donald A. Yee

Faculty Publications

Food quality and quantity serve as the basis for cycling of key chemical elements in trophic interactions; yet the role of nutrient stoichiometry in shaping host–pathogen interactions is under appreciated. Most of the emergent mosquito-borne viruses affecting human health are transmitted by mosquitoes that inhabit container systems during their immature stages, where allochthonous input of detritus serves as the basal nutrients. Quantity and type of detritus (animal and plant) were manipulated in microcosms containing newly hatched Aedes aegypti mosquito larvae. Adult mosquitoes derived from these microcosms were allowed to ingest Zika virus-infected blood and then tested for disseminated infection, transmission, …


Discovery And Characterization Of Bacteriophage Luckybarnes, Savannah L. Underwood, Amanda Foto, Amanda F. Ray, Alexander E. Nelms, Keyshawn L. Kennedy, Shelby G. Hartley, Logan M. Ryals, Chandan Gurung, William A. D'Angelo, Welkin H. Pope, Dmitri V. Mavrodi Jun 2019

Discovery And Characterization Of Bacteriophage Luckybarnes, Savannah L. Underwood, Amanda Foto, Amanda F. Ray, Alexander E. Nelms, Keyshawn L. Kennedy, Shelby G. Hartley, Logan M. Ryals, Chandan Gurung, William A. D'Angelo, Welkin H. Pope, Dmitri V. Mavrodi

Faculty Publications

Here, we report the genome sequence of LuckyBarnes, a newly isolated singleton siphovirus that infects Brevibacterium iodinum ATCC 15728 and has a 50,774-bp genome with 67 predicted genes.


Repurposing Of Glycine-Rich Proteins In Abiotic And Biotic Stresses In The Lone-Star Tick (Amblyomma Americanum), Rebekah Bullard, Surendra Raj Sharma, Pradipta Kumar Das, Sarah E. Morgan, Shahid Karim Jun 2019

Repurposing Of Glycine-Rich Proteins In Abiotic And Biotic Stresses In The Lone-Star Tick (Amblyomma Americanum), Rebekah Bullard, Surendra Raj Sharma, Pradipta Kumar Das, Sarah E. Morgan, Shahid Karim

Faculty Publications

Tick feeding requires the secretion of a huge number of pharmacologically dynamic proteins and other molecules which are vital for the formation of the cement cone, the establishment of the blood pool and to counter against the host immune response. Glycine-rich proteins (GRP) are found in many organisms and can function in a variety of cellular processes and structures. The functional characterization of the GRPs in the tick salivary glands has not been elucidated. GRPs have been found to play a role in the formation of the cement cone; however, new evidence suggests repurposing of GRPs in the tick physiology. …


Linking Water Quality To Aedes Aegypti And Zika In Flood-Prone Neighborhoods, Susan Harrell Yee, Donald A. Yee, Rebeca De Jesus Crespo, Autumn Oczkowski, Fengwei Bai, Stephanie Friedman Jun 2019

Linking Water Quality To Aedes Aegypti And Zika In Flood-Prone Neighborhoods, Susan Harrell Yee, Donald A. Yee, Rebeca De Jesus Crespo, Autumn Oczkowski, Fengwei Bai, Stephanie Friedman

Faculty Publications

The ability of ecosystems to regulate water quality and flood events has been linked to health outcomes, including mosquito-borne illnesses. In the San Juan Bay Estuary watershed of Puerto Rico, habitat alterations and land-use development have disrupted watershed hydrology, exacerbating wastewater discharges and subjecting some neighborhoods to frequent flooding events. In 2016, the mosquito-borne illness Zika became a new cause for concern. We hypothesized that nutrient-enriched flood water could provide pulses of supplemental nutrients to local mosquito populations. We conducted a field study in six neighborhoods adjacent to the estuary to assess whether environmental variability of nutrient inputs could be …


Is Selenoprotein K Required For Borrelia Burgdorferi Infection Within The Tick Vector Ixodes Scapularis?, Deepak Kumar, Monica Embers, Thomas N. Mather, Shahid Karim Jun 2019

Is Selenoprotein K Required For Borrelia Burgdorferi Infection Within The Tick Vector Ixodes Scapularis?, Deepak Kumar, Monica Embers, Thomas N. Mather, Shahid Karim

Faculty Publications

Background: Tick selenoproteins are involved in regulating oxidative and endoplasmic reticulum stress during prolonged tick feeding on mammalian hosts. How selenoproteins are activated upon tick-borne pathogen infection is yet to be defined.

Methods: To examine the functional role of selenoprotein K in Borrelia burgdorferi infection within the tick host Ixodes scapularis, RNA interference (RNAi)-based gene silencing was performed.

Results: Selenoprotein K is an endoplasmic reticulum (ER)-resident protein and a component of the ERAD complex involved in ER homeostasis. A qRT-PCR assay revealed the significant upregulation of selenogene K (selenoK) expression in B. burgdorferi-infected …


Comparison Of Anthracnose Resistance With The Presence Of Two Scar Markers Associated With The Rca2 Gene In Strawberry, Melinda A. Miller-Butler, Barbara J. Smith, Brian R. Kreiser, Eugene K. Blythe May 2019

Comparison Of Anthracnose Resistance With The Presence Of Two Scar Markers Associated With The Rca2 Gene In Strawberry, Melinda A. Miller-Butler, Barbara J. Smith, Brian R. Kreiser, Eugene K. Blythe

Faculty Publications

Strawberry anthracnose diseases are caused primarily by three Colletotrichum species: C. acutatum J.H. Simmonds, C. fragariae A.N. Brooks, and C. gloeosporioides (Penz.) Penz. & Sacc. Molecular markers are being used in breeding programs to identify alleles linked to disease resistance and other positive agronomic traits. In our study, strawberry cultivars and breeding germplasm with known anthracnose susceptibility or resistance to the three anthracnose-causing Colletotrichum species were screened for two sequence characterized amplified region (SCAR) markers linked to the Rca2 gene. The Rca2 resistant allele SCAR markers were associated with varying degrees of significance for a strawberry plant’s anthracnose resistance to …


Algal-Mediated Priming Effects On The Ecological Stoichiometry Of Leaf Litter Decomposition: A Meta-Analysis, Halvor M. Halvorson, Steven N. Francoeur, Robert H. Findlay, Kevin A. Kuehn Apr 2019

Algal-Mediated Priming Effects On The Ecological Stoichiometry Of Leaf Litter Decomposition: A Meta-Analysis, Halvor M. Halvorson, Steven N. Francoeur, Robert H. Findlay, Kevin A. Kuehn

Faculty Publications

In aquatic settings, periphytic algae exude labile carbon (C) that can significantly suppress or stimulate heterotrophic decomposition of recalcitrant C via priming effects. The magnitude and direction of priming effects may depend on the availability and stoichiometry of nutrients like nitrogen (N) and phosphorus (P), which can constrain algal and heterotrophic activity; in turn, priming may affect heterotrophic acquisition not only of recalcitrant C, but also N and P. In this study, we conducted a meta-analysis of algal-mediated priming across leaf litter decomposition experiments to investigate (1) bottom-up controls on priming intensity by dissolved N and P concentrations, and (2) …


The Strength Of Migratory Connectivity For Birds En Route To Breeding Through The Gulf Of Mexico, Emily B. Cohen, Clark R. Rushing, Frank R. Moore, Michael T. Hallworth, Jeffrey A. Hostetler, Mariamar Gutierrez Ramirez, Peter P. Marra Apr 2019

The Strength Of Migratory Connectivity For Birds En Route To Breeding Through The Gulf Of Mexico, Emily B. Cohen, Clark R. Rushing, Frank R. Moore, Michael T. Hallworth, Jeffrey A. Hostetler, Mariamar Gutierrez Ramirez, Peter P. Marra

Faculty Publications

The strength of migratory connectivity is a measure of the cohesion of populations among phases of the annual cycle, including breeding, migration, and wintering. Many Nearctic‐Neotropical species have strong migratory connectivity between breeding and wintering phases of the annual cycle. It is less clear if this strength persists during migration when multiple endogenous and exogenous factors may decrease the cohesion of populations among routes or through time along the same routes. We sampled three bird species, American redstart Setophaga ruticilla, ovenbird Seiurus aurocapilla, and wood thrush Hylocichla mustelina, during spring migration through the Gulf of Mexico region …


Periphytic Algae Decouple Fungal Activity From Leaf Litter Decomposition Via Negative Priming, Halvor M. Halvorson, Jacob R. Barry, Matthew B. Lodato, Robert H. Findlay, Steven N. Francoeur, Kevin A. Kuehn Jan 2019

Periphytic Algae Decouple Fungal Activity From Leaf Litter Decomposition Via Negative Priming, Halvor M. Halvorson, Jacob R. Barry, Matthew B. Lodato, Robert H. Findlay, Steven N. Francoeur, Kevin A. Kuehn

Faculty Publications

1. Well‐documented in terrestrial settings, priming effects describe stimulated heterotrophic microbial activity and decomposition of recalcitrant carbon by additions of labile carbon. In aquatic settings, algae produce labile exudates which may elicit priming during organic matter decomposition, yet the directions and mechanisms of aquatic priming effects remain poorly tested.

2. We tested algal‐induced priming during decomposition of two leaf species of contrasting recalcitrance, Liriodendron tulipifera and Quercus nigra, in experimental streams under light or dark conditions. We measured litter‐associated algal, bacterial, and fungal biomass and activity, stoichiometry, and litter decomposition rates over 43 days.

3. Light increased algal biomass and …


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 Dec 2018

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. Nov 2018

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 …


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 Oct 2018

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 Aug 2018

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. …


Detection And Verification Of Mammalian Mirtrons By Northern Blotting, Mohammad Farid Zia, Alex S. Flynt Jun 2018

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 May 2018

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 …


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 Apr 2018

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 Mar 2018

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 Mar 2018

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 …


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 Feb 2018

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 Jan 2018

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 …


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 Jan 2018

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 …