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Full-Text Articles in Life Sciences

Mapk-Mediated Transcription Factor Gatad Contributes To Cry1ac Resistance In Diamondback Moth By Reducing Pxmalp Expression, Le Guo, Zhouqiang Cheng, Jianying Qin, Dan Sun, Shaoli Wang, Qingjun Wu, Neil Crickmore, Xuguo Zhou, Alejandra Bravo, Mario Soberón, Zhaojiang Guo, Youjun Zhang Feb 2022

Mapk-Mediated Transcription Factor Gatad Contributes To Cry1ac Resistance In Diamondback Moth By Reducing Pxmalp Expression, Le Guo, Zhouqiang Cheng, Jianying Qin, Dan Sun, Shaoli Wang, Qingjun Wu, Neil Crickmore, Xuguo Zhou, Alejandra Bravo, Mario Soberón, Zhaojiang Guo, Youjun Zhang

Entomology Faculty Publications

The benefits of biopesticides and transgenic crops based on the insecticidal Cry-toxins from Bacillus thuringiensis (Bt) are considerably threatened by insect resistance evolution, thus, deciphering the molecular mechanisms underlying insect resistance to Bt products is of great significance to their sustainable utilization. Previously, we have demonstrated that the down-regulation of PxmALP in a strain of Plutella xylostella (L.) highly resistant to the Bt Cry1Ac toxin was due to a hormone-activated MAPK signaling pathway and contributed to the resistance phenotype. However, the underlying transcriptional regulatory mechanism remains enigmatic. Here, we report that the PxGATAd transcription factor (TF) is responsible for the …


Ppld Is A De-N-Acetylase Of The Cell Wall Linkage Unit Of Streptococcal Rhamnopolysaccharides, Jeffrey S. Rush, Prakash Parajuli, Alessandro Ruda, Jian Li, Amol Arunrao Pohane, Svetlana Zamakhaeva, Mohammad M. Rahman, Jennifer C. Chang, Artemis Gogos, Cameron W. Kenner, Gérard Lambeau, Michael J. Federle, Konstantin V. Korotkov, Göran Widmalm, Natalia Korotkova Feb 2022

Ppld Is A De-N-Acetylase Of The Cell Wall Linkage Unit Of Streptococcal Rhamnopolysaccharides, Jeffrey S. Rush, Prakash Parajuli, Alessandro Ruda, Jian Li, Amol Arunrao Pohane, Svetlana Zamakhaeva, Mohammad M. Rahman, Jennifer C. Chang, Artemis Gogos, Cameron W. Kenner, Gérard Lambeau, Michael J. Federle, Konstantin V. Korotkov, Göran Widmalm, Natalia Korotkova

Molecular and Cellular Biochemistry Faculty Publications

The cell wall of the human bacterial pathogen Group A Streptococcus (GAS) consists of peptidoglycan decorated with the Lancefield group A carbohydrate (GAC). GAC is a promising target for the development of GAS vaccines. In this study, employing chemical, compositional, and NMR methods, we show that GAC is attached to peptidoglycan via glucosamine 1-phosphate. This structural feature makes the GAC-peptidoglycan linkage highly sensitive to cleavage by nitrous acid and resistant to mild acid conditions. Using this characteristic of the GAS cell wall, we identify PplD as a protein required for deacetylation of linkage N-acetylglucosamine (GlcNAc). X-ray structural analysis indicates …


Dissecting The Role Of Actin-Myosin Motor And Calcium – Based Organelle Secretion In Motility Of Sarcocystis Neurona, Parul Suri Jan 2022

Dissecting The Role Of Actin-Myosin Motor And Calcium – Based Organelle Secretion In Motility Of Sarcocystis Neurona, Parul Suri

Theses and Dissertations--Veterinary Science

Sarcocystis neurona is a protozoan parasite that causes a rare neurological disorder in horses called Equine Protozoal Myeloencephalitis (EPM). Apicomplexa use actin-myosin based motor and organelle secretion to interact with the host cell and invade it. Despite the importance of motility and invasion-needed factors, the mechanisms by which S. neurona employs host cell association strategies to interact remains largely undefined. To address this knowledge gap, we hypothesize that just like other Apicomplexa, S. neurona utilizes actin polymerization for substrate-dependent gliding. Moreover, we also hypothesize that micronemes of S. neurona secrete proteins that are calcium-dependent. Based on previous studies in T. …


An Investigation Of Hhv6'S Impact On The Cognitive Progression And Microglial Changes In An Alzheimer's Disease Cohort, Charles E. Seaks Jan 2022

An Investigation Of Hhv6'S Impact On The Cognitive Progression And Microglial Changes In An Alzheimer's Disease Cohort, Charles E. Seaks

Theses and Dissertations--Physiology

The role of herpesviruses and, more specifically, HHV6 in the development of Alzheimer’s disease (AD) and associated cognitive decline is still being investigated. High ubiquity and prevalence in the population have led to a high degree of skepticism about HHV6 as a potential contributor to cognitive decline and dementias. However, recent evidence related to another herpesvirus, herpes simplex virus 1, suggests that reactivation, not carriage, of the virus may be the key factor to explain the dissonance between the virus’ ubiquity and contributions to dementias. With that in mind, we set out to assess cases from the Sanders-Brown Center on …


A Multidisciplinary Characterization Of The Enzymology And Biology Of Reversible Glucan Phosphorylation In Toxoplasma Gondii , Robert Murphy Jan 2022

A Multidisciplinary Characterization Of The Enzymology And Biology Of Reversible Glucan Phosphorylation In Toxoplasma Gondii , Robert Murphy

Theses and Dissertations--Molecular and Cellular Biochemistry

Toxoplasma gondii is an opportunistic, protozoan parasite of all warm-blooded animals, infecting roughly one-third of humans worldwide. Humans acquire infections by consuming T. gondii tissue cysts in undercooked meat or from oocysts shed in cat feces. Encysted parasites convert into rapidly growing tachyzoites that disseminate throughout the body, defining the acute phase of infection. Under host immune pressure, tachyzoites convert into bradyzoites that populate tissue cysts found in CNS or muscle tissue and persist for the lifetime of the host, defining the chronic phase of infection. Tissue cysts are responsible for transmission via carnivory, but also possess the ability to …


Regulation Of Skeletal Muscle Plasticity By The Gut Microbiome, Taylor R. Valentino Jan 2022

Regulation Of Skeletal Muscle Plasticity By The Gut Microbiome, Taylor R. Valentino

Theses and Dissertations--Physiology

Recent evidence suggests that the gut microbiome could play a role in skeletal muscle plasticity, providing novel treatments for muscle wasting diseases and/or performance enhancements. I first sought to determine if the gut microbiome is necessary for skeletal muscle adaptation to exercise. Forty-two, four-month old, female C57Bl/6J underwent nine weeks of weighted wheel running or remained in cage with a locked wheel, without or without the administration of antibiotics (treated). In response to wheel running, I found that antibiotic depletion of the microbiome led to a blunted hypertrophic response in the soleus muscle as measured by normalized muscle wet weight …


Antibiotic Permeation In Gram-Negative Bacteria And Contribution Of Inflammasome Activation And Pyroptosis In Pathogenesis Of Salmonella Systemic Infection, Ankit Pandeya Jan 2022

Antibiotic Permeation In Gram-Negative Bacteria And Contribution Of Inflammasome Activation And Pyroptosis In Pathogenesis Of Salmonella Systemic Infection, Ankit Pandeya

Theses and Dissertations--Chemistry

Antibiotic resistance is one of the major global issues in the field of public health and medicine. Good antibiotic candidates need to be selectively toxic, inhibit cellular target, and effectively penetrate and accumulate in bacterial cells. The last factor is a formidable barrier in the development of antimicrobials effective in Gram-negative bacteria, due to the presence of two layers of cell envelope. The first half of my thesis focuses on understanding the permeation of small molecules through this formidable cell envelope, distribution inside the cell of Gram-negative bacteria, and design of novel methods to make small molecules effectively cross the …


Exploration Of Lignin-Based Superabsorbent Polymers (Hydrogels) For Soil Water Management And As A Carrier For Delivering Rhizobium Spp., Toby Adjuik Jan 2022

Exploration Of Lignin-Based Superabsorbent Polymers (Hydrogels) For Soil Water Management And As A Carrier For Delivering Rhizobium Spp., Toby Adjuik

Theses and Dissertations--Biosystems and Agricultural Engineering

Superabsorbent polymers (hydrogels) as soil amendments may improve soil hydraulic properties and act as carrier materials beneficial to soil microorganisms. Researchers have mostly explored synthetic hydrogels which may not be environmentally sustainable. This dissertation focused on the development and application of lignin-based hydrogels as sustainable soil amendments. This dissertation also explores the development of pedotransfer transfer functions (PTFs) for predicting saturated hydraulic conductivity using statistical and machine learning methods with a publicly available large data set. A lignin-based hydrogel was synthesized, and its impact on soil water retention was determined in silt loam and loamy fine sand soils. Hydrogel treatment …