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Articles 31 - 60 of 1010

Full-Text Articles in Biology

Morphology And Molecular Systematics Support A New Species Of Pseudogonatodes (Squamata: Gekkota: Sphaerodactylidae) From Venezuela With A Remarkable Telescoped Skull, Walter E. Schargel, Christian Hernández-Morales, Juan D. Daza, Micheal J. Jowers, Andres Camilo Montes-Correa, Mayke De Freitas, Kathryn A. Sullivan, Tony Gamble, Aaron M. Bauer, Gilson A. Rivas Oct 2024

Morphology And Molecular Systematics Support A New Species Of Pseudogonatodes (Squamata: Gekkota: Sphaerodactylidae) From Venezuela With A Remarkable Telescoped Skull, Walter E. Schargel, Christian Hernández-Morales, Juan D. Daza, Micheal J. Jowers, Andres Camilo Montes-Correa, Mayke De Freitas, Kathryn A. Sullivan, Tony Gamble, Aaron M. Bauer, Gilson A. Rivas

Biological Sciences Faculty Research and Publications

We describe a new species of miniaturized gecko (genus Pseudogonatodes) from the Peninsula de Paria in northeastern Venezuela. Externally, the new species resembles Pseudogonatodes furvus and Pseudogonatodes manessi, from the Sierra Nevada de Santa Marta in Colombia and the Central Coastal Range in Venezuela, respectively; however, it differs from these species in terms of molecular genetic data (12S rRNA, 16S rRNA, and c-mos), osteological characters, and scale counts. The new species is unique in skull osteology, and we adopt the term ‘telescoped’ from the literature to describe the overlap of bones in the snout, in particular the …

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The Middle Domain Of Hsp104 Can Ensure Substrates Are Functional After Processing, Hannah Buchholz, Jane E. Dorweiler, Sam Guereca, Brett T. Wisniewski, James Shorter, Anita L. Manogaran Oct 2024

The Middle Domain Of Hsp104 Can Ensure Substrates Are Functional After Processing, Hannah Buchholz, Jane E. Dorweiler, Sam Guereca, Brett T. Wisniewski, James Shorter, Anita L. Manogaran

Biological Sciences Faculty Research and Publications

Molecular chaperones play a central role in protein disaggregation. However, the molecular determinants that regulate this process are poorly understood. Hsp104 is an AAA+ ATPase that disassembles stress granules and amyloids in yeast through collaboration with Hsp70 and Hsp40. In vitro studies show that Hsp104 processes different types of protein aggregates by partially translocating or threading polypeptides through the central pore of the hexamer. However, it is unclear how Hsp104 processing influences client protein function in vivo. The middle domain (MD) of Hsp104 regulates ATPase activity and interactions with Hsp70. Here, we tested how MD variants, Hsp104A503S and …

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Exploring The Influence Of Molecular Chaperones On The Aggregation Of Transthyretin, Adam S. Knier Oct 2024

Exploring The Influence Of Molecular Chaperones On The Aggregation Of Transthyretin, Adam S. Knier

Dissertations (1934 -)

Molecular chaperones assist in maintaining protein homeostasis by limiting protein aggregation, including populations of protein aggregates that may be associated with the onset of debilitating and/or often fatal diseases. Chaperones are known to limit protein aggregate populations through disaggregase activity, in which chaperone complexes work together to disassemble multi-subunit aggregate species into smaller populations, or holdase activity, in which chaperones bind to proteins or smaller aggregates to prevent further aggregation. In this dissertation we assess if molecular chaperones can limit the aggregation of human transthyretin (TTR) expressed within a yeast system and explore the relationship between chaperone concentration and activity. …

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Cardiomyocyte Adaptation To Exercise: K+ Channels, Contractility And Ischemic Injury, Robert H. Fitts, Xinrui Wang, Wai-Meng Kwok, Amadou K.S. Camara Oct 2024

Cardiomyocyte Adaptation To Exercise: K+ Channels, Contractility And Ischemic Injury, Robert H. Fitts, Xinrui Wang, Wai-Meng Kwok, Amadou K.S. Camara

Biological Sciences Faculty Research and Publications

Cardiovascular disease is a leading cause of morbidity and mortality, and exercise-training (TRN) is known to reduce risk factors and protect the heart from ischemia and reperfusion injury. Though the cardioprotective effects of exercise are well-documented, underlying mechanisms are not well understood. This review highlights recent findings and focuses on cardiac factors with emphasis on K+ channel control of the action potential duration (APD), β-adrenergic and adenosine regulation of cardiomyocyte function, and mitochondrial Ca2+ regulation. TRN-induced prolongation and shortening of the APD at low and high activation rates, respectively, is discussed in the context of a reduced response …

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Consequences Of Local Conspecific Density Effects For Plant Diversity And Community Dynamics, Joseph A. Lamanna, Stefan A. Schnitzer Sep 2024

Consequences Of Local Conspecific Density Effects For Plant Diversity And Community Dynamics, Joseph A. Lamanna, Stefan A. Schnitzer

Biological Sciences Faculty Research and Publications

Conspecific density dependence (CDD) in plant populations is widespread, most likely caused by local-scale biotic interactions, and has potentially important implications for biodiversity, community composition, and ecosystem processes. However, progress in this important area of ecology has been hindered by differing viewpoints on CDD across subfields in ecology, lack of synthesis across CDD-related frameworks, and misunderstandings about how empirical measurements of local CDD fit within the context of broader ecological theories on community assembly and diversity maintenance. Here, we propose a conceptual synthesis of local-scale CDD and its causes, including species-specific antagonistic and mutualistic interactions. First, we compare and clarify …

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Cystic Fibrosis Pathogens Persist In The Upper Respiratory Tract Following Initiation Of Elexacaftor/Tezacaftor/Ivacaftor Therapy, Yasmin K. Hilliam, Catherine R. Armbruster, Glenn J. Rapsinski, Christopher W. Marshall, John Moore, Junu Koirala, Leah Krainz, Jordan R. Gaston, Vaughn S. Cooper, Stella E. Lee, Jennifer M. Bomberger Aug 2024

Cystic Fibrosis Pathogens Persist In The Upper Respiratory Tract Following Initiation Of Elexacaftor/Tezacaftor/Ivacaftor Therapy, Yasmin K. Hilliam, Catherine R. Armbruster, Glenn J. Rapsinski, Christopher W. Marshall, John Moore, Junu Koirala, Leah Krainz, Jordan R. Gaston, Vaughn S. Cooper, Stella E. Lee, Jennifer M. Bomberger

Biological Sciences Faculty Research and Publications

Elexacaftor/tezacaftor/ivacaftor (ETI) therapy has revolutionized the treatment of cystic fibrosis (CF) for most affected individuals but the effects of treatment on sinus microbiota are still unknown. Changes to the airway microbiota in CF are associated with disease state and alterations to the bacterial community after ETI initiation may require changes to clinical management regimens. We collected sinus swab samples from the middle meatus in an observational study of 38 adults with CF and chronic rhinosinusitis (CRS) from 2017 to 2021 and captured the initiation of ETI therapy. We performed 16S and custom amplicon sequencing to characterize the sinus microbiota pre- …

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Linking Physiology, Epidemiology, And Demography: Understanding How Lianas Outcompete Trees In A Changing World, Hannes De Deurwaerder, Matteo Detto, Marco Visser, Stefan A. Schnitzer, Stephen W. Pacala Aug 2024

Linking Physiology, Epidemiology, And Demography: Understanding How Lianas Outcompete Trees In A Changing World, Hannes De Deurwaerder, Matteo Detto, Marco Visser, Stefan A. Schnitzer, Stephen W. Pacala

Biological Sciences Faculty Research and Publications

Extending and safeguarding tropical forest ecosystems is critical for combating climate change and biodiversity loss. One of its constituents, lianas, is spreading and increasing in abundance on a global scale. This is particularly concerning as lianas negatively impact forests’ carbon fluxes, dynamics, and overall resilience, potentially exacerbating both crises. While possibly linked to climate-change-induced atmospheric CO2 elevation and drought intensification, the reasons behind their increasing abundance remain elusive. Prior research shows distinct physiological differences between lianas and trees, but it is unclear whether these differences confer a demographic advantage to lianas with climate change. Guided by extensive datasets collected …

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The Role Of Obesity In The Development Of Disordered Breathing, Sarah N. Framnes-Deboer Jul 2024

The Role Of Obesity In The Development Of Disordered Breathing, Sarah N. Framnes-Deboer

Master's Theses (2009 -)

Obesity is a complex disease that is defined by an excess amount of body fat. Obesity can have physical, neurological, and endocrine effects and detrimental effects on health. Some obese co-morbid conditions, such as type 2 diabetes have known mechanisms, while others, such as sleep disordered breathing do not. Moreover, there are common respiratory diseases associated with obesity, such as obstructive sleep apnea and obesity hypoventilation syndrome. Furthermore, individuals with obesity or obstructive sleep apnea have a blunted hypercapnic ventilatory response (HCVR) (120), which is indicative of impaired chemosensitivity, as HCVR is a measure of how well an individual responds …

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Time-Restricted Feeding Reveals A Role For Neural Respiratory Clocks In Optimizing Daily Ventilatory-Metabolic Coupling In Mice, Aaron A. Jones, Gabriella M. Marino, Deanna M. Arble Jul 2024

Time-Restricted Feeding Reveals A Role For Neural Respiratory Clocks In Optimizing Daily Ventilatory-Metabolic Coupling In Mice, Aaron A. Jones, Gabriella M. Marino, Deanna M. Arble

Biological Sciences Faculty Research and Publications

The master circadian clock, located in the suprachiasmatic nuclei (SCN), organizes the daily rhythm in minute ventilation (V̇e). However, the extent that the daily rhythm in V̇e is secondary to SCN-imposed O2 and CO2 cycles (i.e., metabolic rate) or driven by other clock mechanisms remains unknown. Here, we experimentally shifted metabolic rate using time-restricted feeding (without affecting light-induced synchronization of the SCN) to determine the influence of metabolic rate in orchestrating the daily V̇e rhythm. Mice eating predominantly at night exhibited robust daily rhythms in O2 consumption (V̇o2), CO2 production (V̇co2), and V̇e with similar peak times (approximately ZT18) that …

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The Unexpected Influence Of Legacy Conspecific Density Dependence, Lukas J. Magee, Joseph A. Lamanna, Amy T. Wolf, Robert W. Howe, Yuanming Lu, Denis Valle, Daniel J. B. Smith, Robert Bagchi, David Bauman, Daniel J. Johnson Jun 2024

The Unexpected Influence Of Legacy Conspecific Density Dependence, Lukas J. Magee, Joseph A. Lamanna, Amy T. Wolf, Robert W. Howe, Yuanming Lu, Denis Valle, Daniel J. B. Smith, Robert Bagchi, David Bauman, Daniel J. Johnson

Biological Sciences Faculty Research and Publications

When plants die, neighbours escape competition. Living conspecifics could disproportionately benefit because they are freed from negative intraspecific processes; however, if the negative effects of past conspecific neighbours persist, other species might be advantaged, and diversity might be maintained through legacy effects. We examined legacy effects in a mapped forest by modelling the survival of 37,212 trees of 23 species using four neighbourhood properties: living conspecific, living heterospecific, legacy conspecific (dead conspecifics) and legacy heterospecific densities. Legacy conspecific effects proved nearly four times stronger than living conspecific effects; changes in annual survival associated with legacy conspecific density were 1.5% greater …

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Persistence And Evolution Of Pseudomonas Aeruginosa Following Initiation Of Highly Effective Modulator Therapy In Cystic Fibrosis, Catherine R. Armbruster, Yasmin K. Hilliam, Anna C. Zemke, Samar Atteih, Christopher Marshall, John Moore, Junu Koirala, Leah Krainz, Jordan R. Gaston, Stella E. Lee, Vaughn S. Cooper, Jennifer M. Bomberger May 2024

Persistence And Evolution Of Pseudomonas Aeruginosa Following Initiation Of Highly Effective Modulator Therapy In Cystic Fibrosis, Catherine R. Armbruster, Yasmin K. Hilliam, Anna C. Zemke, Samar Atteih, Christopher Marshall, John Moore, Junu Koirala, Leah Krainz, Jordan R. Gaston, Stella E. Lee, Vaughn S. Cooper, Jennifer M. Bomberger

Biological Sciences Faculty Research and Publications

Today, more than 90% of people with cystic fibrosis (pwCF) are eligible for the highly effective cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy called elexacaftor/tezacaftor/ivacaftor (ETI) and its use is widespread. Given the drastic respiratory symptom improvement experienced by many post-ETI, clinical studies are already underway to reduce the number of respiratory therapies, including antibiotic regimens, that pwCF historically relied on to combat lung disease progression. Early studies suggest that bacterial burden in the lungs is reduced post-ETI, yet it is unknown how chronic Pseudomonas aeruginosa populations are impacted by ETI. We found that pwCF remain infected throughout their …

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Indoor Tent Management For Extending Honey Bee Research Season: Benefits And Caveats, Trevor Bawden, Adam G. Dolezal, Chelsea N. Cook May 2024

Indoor Tent Management For Extending Honey Bee Research Season: Benefits And Caveats, Trevor Bawden, Adam G. Dolezal, Chelsea N. Cook

Biological Sciences Faculty Research and Publications

Honey bees are important organisms for research in many fields, including physiology, behavior, and ecology. Honey bee colonies are relatively easy and affordable to procure, manage, and replace. However, some difficulties still exist in honey bee research, specifically that honey bee colonies have a distinct seasonality, especially in temperate regions. Honey bee colonies transition from a large society in which workers have a strict temporal division of labor in the summer, to a group of behaviorally flexible workers who manage the colony over winter. Furthermore, opening colonies or collecting bees when they are outside has the potential to harm the …

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The Buzz Within: The Role Of The Gut Microbiome In Honeybee Social Behavior, J. B. Nguyen, Christopher Marshall, Chelsea N. Cook Feb 2024

The Buzz Within: The Role Of The Gut Microbiome In Honeybee Social Behavior, J. B. Nguyen, Christopher Marshall, Chelsea N. Cook

Biological Sciences Faculty Research and Publications

Gut symbionts influence the physiology and behavior of their host, but the extent to which these effects scale to social behaviors is an emerging area of research. The use of the western honeybee (Apis mellifera) as a model enables researchers to investigate the gut microbiome and behavior at several levels of social organization. Insight into gut microbial effects at the societal level is critical for our understanding of how involved microbial symbionts are in host biology. In this Commentary, we discuss recent findings in honeybee gut microbiome research and synthesize these with knowledge of the physiology and behavior …

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Seasonal Soil Moisture Thresholds Inhibit Bacterial Activity And Decomposition During Drought In A Tallgrass Prairie, Nathan P. Lemoine, Michelle L. Budny, Ethan Rose, Jane Lucas, Christopher Marshall Feb 2024

Seasonal Soil Moisture Thresholds Inhibit Bacterial Activity And Decomposition During Drought In A Tallgrass Prairie, Nathan P. Lemoine, Michelle L. Budny, Ethan Rose, Jane Lucas, Christopher Marshall

Biological Sciences Faculty Research and Publications

Soil moisture reductions during drought often inhibit soil microbial activity and inhibit decomposition rates by reducing microbial biomass or by altering microbial communities. Evidence suggests that soil water must drop below a critical threshold to inhibit microbial activity. Thus, it is likely that the seasonal timing of drought will determine the extent to which belowground processes are adversely impacted by drought. Specifically, the effects of drought might be minimal during cool, wet periods typical of late spring but dramatic during hot summer months with high evapotranspiration rates that lower soil moisture levels below the critical threshold. Here, we present results …

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Schizachyrium Scoparium (C4) Better Tolerates Drought Than Andropogon Gerardii (C4) Via Constant Co2 Supply For Photosynthesis During Water Stress, Alina Dekirmenjian, Diego Montano, Michelle L. Budny, Nathan P. Lemoine Feb 2024

Schizachyrium Scoparium (C4) Better Tolerates Drought Than Andropogon Gerardii (C4) Via Constant Co2 Supply For Photosynthesis During Water Stress, Alina Dekirmenjian, Diego Montano, Michelle L. Budny, Nathan P. Lemoine

Biological Sciences Faculty Research and Publications

Climate change is dramatically altering global precipitation patterns across terrestrial ecosystems, making it critically important that we understand both how and why plant species vary in their drought sensitivities. Andropogon gerardii and Schizachyrium scoparium, both C4 grasses, provide a model system for understanding the physiological mechanisms that determine how species of a single functional type can differ in drought responses, an issue remains a critical gap in our ability to model and predict the impacts of drought on grassland ecosystems. Despite its greater lability of foliar water content, previous experiments have demonstrated that S. scoparium maintains higher photosynthetic …

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Ai Is A Viable Alternative To High Throughput Screening: A 318-Target Study, Martin St. Maurice Jan 2024

Ai Is A Viable Alternative To High Throughput Screening: A 318-Target Study, Martin St. Maurice

Biological Sciences Faculty Research and Publications

High throughput screening (HTS) is routinely used to identify bioactive small molecules. This requires physical compounds, which limits coverage of accessible chemical space. Computational approaches combined with vast on-demand chemical libraries can access far greater chemical space, provided that the predictive accuracy is sufficient to identify useful molecules. Through the largest and most diverse virtual HTS campaign reported to date, comprising 318 individual projects, we demonstrate that our AtomNet® convolutional neural network successfully finds novel hits across every major therapeutic area and protein class. We address historical limitations of computational screening by demonstrating success for target proteins without known binders, …

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Bacillus Subtilis-Derived Peptides Disrupt Quorum Sensing And Biofilm Assembly In Multidrug-Resistant Staphylococcus Aureus, Kyle R. Leistikow, Daniel S. May, Won Se Suh, Gabriel Vargas Asensio, Adam J. Schaenzer, Cameron R. Currie, Krassimira R. Hristova Jan 2024

Bacillus Subtilis-Derived Peptides Disrupt Quorum Sensing And Biofilm Assembly In Multidrug-Resistant Staphylococcus Aureus, Kyle R. Leistikow, Daniel S. May, Won Se Suh, Gabriel Vargas Asensio, Adam J. Schaenzer, Cameron R. Currie, Krassimira R. Hristova

Biological Sciences Faculty Research and Publications

Multidrug-resistant Staphylococcus aureus is one of the most clinically important pathogens in the world, with infections leading to high rates of morbidity and mortality in both humans and animals. The ability of S. aureus to form biofilms protects cells from antibiotics and promotes the transfer of antibiotic resistance genes; therefore, new strategies aimed at inhibiting biofilm growth are urgently needed. Probiotic species, including Bacillus subtilis, are gaining interest as potential therapies against S. aureus for their ability to reduce S. aureus colonization and virulence. Here, we search for strains and microbially derived compounds with strong antibiofilm activity against multidrug-resistant S. …

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Clearing The Junq: The Molecular Machinery For Sequestration, Localization, And Degradation Of The Junq Compartment, Sarah Rolli, Chloe A. Langridge, Emily M. Sontag Jan 2024

Clearing The Junq: The Molecular Machinery For Sequestration, Localization, And Degradation Of The Junq Compartment, Sarah Rolli, Chloe A. Langridge, Emily M. Sontag

Biological Sciences Faculty Research and Publications

Cellular protein homeostasis (proteostasis) plays an essential role in regulating the folding, sequestration, and turnover of misfolded proteins via a network of chaperones and clearance factors. Previous work has shown that misfolded proteins are spatially sequestered into membrane-less compartments in the cell as part of the proteostasis process. Soluble misfolded proteins in the cytoplasm are trafficked into the juxtanuclear quality control compartment (JUNQ), and nuclear proteins are sequestered into the intranuclear quality control compartment (INQ). However, the mechanisms that control the formation, localization, and degradation of these compartments are unknown. Previously, we showed that the JUNQ migrates to the nuclear …

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Identification Of Mimas, A Multifunctional Mega-Assembly Integrating Metabolic And Respiratory Biogenesis Factors Of Mitochondria, Rosemary A. Stuart Jan 2024

Identification Of Mimas, A Multifunctional Mega-Assembly Integrating Metabolic And Respiratory Biogenesis Factors Of Mitochondria, Rosemary A. Stuart

Biological Sciences Faculty Research and Publications

The mitochondrial inner membrane plays central roles in bioenergetics and metabolism and contains several established membrane protein complexes. Here, we report the identification of a mega-complex of the inner membrane, termed mitochondrial multifunctional assembly (MIMAS). Its large size of 3 MDa explains why MIMAS has escaped detection in the analysis of mitochondria so far. MIMAS combines proteins of diverse functions from respiratory chain assembly to metabolite transport, dehydrogenases, and lipid biosynthesis but not the large established supercomplexes of the respiratory chain, ATP synthase, or prohibitin scaffold. MIMAS integrity depends on the non-bilayer phospholipid phosphatidylethanolamine, in contrast to respiratory supercomplexes whose …

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Developmental Patterns Underlying Variation In Form And Function Exhibited By House Gecko Toe Pads, Aaron H. Griffing, Tony Gamble, Ashmika Behere, Timothy E. Higham, Greta M. Keller, John Resener, Thomas J. Sanger Jan 2024

Developmental Patterns Underlying Variation In Form And Function Exhibited By House Gecko Toe Pads, Aaron H. Griffing, Tony Gamble, Ashmika Behere, Timothy E. Higham, Greta M. Keller, John Resener, Thomas J. Sanger

Biological Sciences Faculty Research and Publications

Adhesive toe pads have evolved numerous times over lizard evolutionary history, most notably in geckos. Despite significant variation in adult toe pad morphology across independent origins of toe pads, early developmental patterns of toe pad morphogenesis are similar among distantly related species. In these distant phylogenetic comparisons, toe pad variation is achieved during the later stages of development. We aimed to understand how toe pad variation is generated among species sharing a single evolutionary origin of toe pads (house geckos—Hemidactylus). We investigated toe pad functional variation and developmental patterns in three species of Hemidactylus, ranging from highly …

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Pseudomonas Mosselii Improves Cold Tolerance Of Asian Rice (Oryza Sativa L.) In A Genotype-Dependent Manner By Increasing Proline In Japonica And Reduced Glutathione In Indica Varieties, Nasim Maghboli Balasjin, James Maki, Michael Schläppi Jan 2024

Pseudomonas Mosselii Improves Cold Tolerance Of Asian Rice (Oryza Sativa L.) In A Genotype-Dependent Manner By Increasing Proline In Japonica And Reduced Glutathione In Indica Varieties, Nasim Maghboli Balasjin, James Maki, Michael Schläppi

Biological Sciences Faculty Research and Publications

Cold stress is an important factor limiting rice production and distribution. Identifying factors that contribute to cold tolerance in rice is of primary importance. While some plant specific genetic factors involved in cold tolerance have been identified, the role of the rice microbiome remains unexplored. In this study, we evaluated the influence of plant growth promoting bacteria (PGPB) with the ability of phosphate solubilization on rice cold tolerance and survival. To reach this goal, inoculated and uninoculated 2-week-old seedlings were cold stressed and evaluated for survival and other phenotypes such as electrolyte leakage (EL) and necessary elements for cold tolerance. …

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It’S A Trap?! Escape From An Ancient, Ancestral Sex Chromosome System And Implication Of Foxl2 As The Putative Primary Sex-Determining Gene In A Lizard (Anguimorpha; Shinisauridae), Brendan J. Pinto, Stuart V. Nielsen, Kathryn A. Sullivan, Ashmika Behere, Shannon E. Keating, Mona Van Schingen-Khan, Truong Q. Nguyen, Thomas Ziegler, Jennifer Pramuk, Melissa A. Wilson, Tony Gamble Jan 2024

It’S A Trap?! Escape From An Ancient, Ancestral Sex Chromosome System And Implication Of Foxl2 As The Putative Primary Sex-Determining Gene In A Lizard (Anguimorpha; Shinisauridae), Brendan J. Pinto, Stuart V. Nielsen, Kathryn A. Sullivan, Ashmika Behere, Shannon E. Keating, Mona Van Schingen-Khan, Truong Q. Nguyen, Thomas Ziegler, Jennifer Pramuk, Melissa A. Wilson, Tony Gamble

Biological Sciences Faculty Research and Publications

Although sex determination is ubiquitous in vertebrates, mechanisms of sex determination vary from environmentally to genetically influenced. In vertebrates, genetic sex determination is typically accomplished with sex chromosomes. Groups like mammals maintain conserved sex chromosome systems, while sex chromosomes in most vertebrate clades are not conserved across similar evolutionary timescales. One group inferred to have an evolutionarily stable mode of sex determination is Anguimorpha, a clade of charismatic taxa including monitor lizards, Gila monsters, and crocodile lizards. The common ancestor of extant anguimorphs possessed a ZW system that has been retained across the clade. However, the sex chromosome system in …

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Differential Conservation And Loss Of Chicken Repeat 1 (Cr1) Retrotransposons In Squamates Reveal Lineage-Specific Genome Dynamics Across Reptiles, Simone M. Gable, Nicholas A. Bushroe, Jasmine M. Mendez, Adam Wilson, Brendan J. Pinto, Tony Gamble, Marc Tollis Jan 2024

Differential Conservation And Loss Of Chicken Repeat 1 (Cr1) Retrotransposons In Squamates Reveal Lineage-Specific Genome Dynamics Across Reptiles, Simone M. Gable, Nicholas A. Bushroe, Jasmine M. Mendez, Adam Wilson, Brendan J. Pinto, Tony Gamble, Marc Tollis

Biological Sciences Faculty Research and Publications

Transposable elements (TEs) are repetitive DNA sequences which create mutations and generate genetic diversity across the tree of life. In amniote vertebrates, TEs have been mainly studied in mammals and birds, whose genomes generally display low TE diversity. Squamates (Order Squamata; including ∼11,000 extant species of lizards and snakes) show as much variation in TE abundance and activity as they do in species and phenotypes. Despite this high TE activity, squamate genomes are remarkably uniform in size. We hypothesize that novel, lineage-specific genome dynamics have evolved over the course of squamate evolution. To understand the interplay between TEs and host …

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Notes On Patagium Morphology In The Gliding Flat-Tailed House Gecko (Hemidactylus Platyurus), Amber M. Petty, Tony Gamble, Aaron H. Griffing Jan 2024

Notes On Patagium Morphology In The Gliding Flat-Tailed House Gecko (Hemidactylus Platyurus), Amber M. Petty, Tony Gamble, Aaron H. Griffing

Biological Sciences Faculty Research and Publications

Several species of geckos have independently evolved patagia, membranous features that facilitate gliding. Detailed morphological investigations of gecko patagia have largely been limited to gliding members of the genus Gekko (formerly in the genus Ptychozoon). Herein we describe the morphology of gliding patagia of the Flat-tailed House Gecko (Hemidactylus platyurus), a species with an independent evolutionary origin of gliding patagia from Gekko and an important species for researching gliding biomechanics. We compared morphology of H. platyurus with a closely related non-gliding species, the Common House Gecko (Hemidactylus frenatus). Using external examination and histological techniques, we …

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Stress Biology: Complexity And Multifariousness In Health And Disease, Emily M. Sontag Jan 2024

Stress Biology: Complexity And Multifariousness In Health And Disease, Emily M. Sontag

Biological Sciences Faculty Research and Publications

Preserving and regulating cellular homeostasis in the light of changing environmental conditions or developmental processes is of pivotal importance for single cellular and multicellular organisms alike. To counteract an imbalance in cellular homeostasis transcriptional programs evolved, called the heat shock response, unfolded protein response, and integrated stress response, that act cell-autonomously in most cells but in multicellular organisms are subjected to cell-nonautonomous regulation. These transcriptional programs downregulate the expression of most genes but increase the expression of heat shock genes, including genes encoding molecular chaperones and proteases, proteins involved in the repair of stress-induced damage to macromolecules and cellular structures. …

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Synthesis And Evaluation Of 1,3-Disubstituted Imidazolidine-2,4,5-Triones As Inhibitors Of Pyruvate Carboxylase, Nicholas O. Schneider, Keandra Gilreath, Niel M. Henriksen, William A. Donaldson, Subhabrata Chaudhury, Martin St. Maurice Jan 2024

Synthesis And Evaluation Of 1,3-Disubstituted Imidazolidine-2,4,5-Triones As Inhibitors Of Pyruvate Carboxylase, Nicholas O. Schneider, Keandra Gilreath, Niel M. Henriksen, William A. Donaldson, Subhabrata Chaudhury, Martin St. Maurice

Biological Sciences Faculty Research and Publications

Substituted imidazolidinetriones (IZTs) have been identified as potent inhibitors of pyruvate carboxylase (PC) through an in silico screening approach. Alkyl 2-(2,4,5-trioxo-3-substituted imidazolidin-1-yl)acetates (6i–6r) are the most potent of the series, with IC50 values between 3 and 12 μM, and several IZTs demonstrate high passive permeability across an artificial membrane. IZTs are mixed-type inhibitors with respect to pyruvate and noncompetitive with respect to ATP. This class of inhibitors appears to be selective for PC. Inhibitors in the IZT series do not inhibit the metalloenzymes human carbonic anhydrase II and matrix metalloprotease-12, and they do not inhibit the related biotin-dependent enzyme, guanidine …

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Importance Of Conserved Hydrophobic Pocket Region In Yeast Mitoribosomal Ml44 Protein For Mitotranslation And Transcript Preference, Jodie M. Box, Margo E. Higgins, Rosemary A. Stuart Jan 2024

Importance Of Conserved Hydrophobic Pocket Region In Yeast Mitoribosomal Ml44 Protein For Mitotranslation And Transcript Preference, Jodie M. Box, Margo E. Higgins, Rosemary A. Stuart

Biological Sciences Faculty Research and Publications

The mitochondrial ribosome (mitoribosome) is responsible for the synthesis of key oxidative phosphorylation subunits encoded by the mitochondrial genome. Defects in mitoribosomal function therefore can have serious consequences for the bioenergetic capacity of the cell. Mutation of the conserved mitoribosomal mL44 protein has been directly linked to childhood cardiomyopathy and progressive neurophysiology issues. To further explore the functional significance of the mL44 protein in supporting mitochondrial protein synthesis, we have performed a mutagenesis study of the yeast mL44 homolog, the MrpL3/mL44 protein. We specifically investigated the conserved hydrophobic pocket region of the MrpL3/mL44 protein, where the known disease-related residue …

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Mutation Of The Pebp-Like Domain Of The Mitoribosomal Mrpl35/Ml38 Protein Results In Production Of Nascent Chains With Impaired Capacity To Assemble Into Oxphos Complexes, Jodie M. Box, Jessica M. Anderson, Rosemary A. Stuart Dec 2023

Mutation Of The Pebp-Like Domain Of The Mitoribosomal Mrpl35/Ml38 Protein Results In Production Of Nascent Chains With Impaired Capacity To Assemble Into Oxphos Complexes, Jodie M. Box, Jessica M. Anderson, Rosemary A. Stuart

Biological Sciences Faculty Research and Publications

Located in the central protuberance region of the mitoribosome and mitospecific mL38 proteins display homology to PEBP (Phosphatidylethanolamine Binding Protein) proteins, a diverse family of proteins reported to bind anionic substrates/ligands and implicated in cellular signaling and differentiation pathways. In this study, we have performed a mutational analysis of the yeast mitoribosomal protein MrpL35/mL38 and demonstrate that mutation of the PEBP-invariant ligand binding residues Asp(D)232 and Arg(R)288 impacted MrpL35/mL38’s ability to support OXPHOS-based growth of the cell. Furthermore, our data indicate these residues exist in a functionally important charged microenvironment, which also includes Asp(D)167 of MrpL35/mL38 and Arg(R)127 of the …

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Moderate Heat Stress-Induced Sterility Is Due To Motility Defects And Reduced Mating Drive In Caenorhabditis Elegans Males, Nicholas B. Sepulveda, Donald Chen, Lisa N. Petrella Oct 2023

Moderate Heat Stress-Induced Sterility Is Due To Motility Defects And Reduced Mating Drive In Caenorhabditis Elegans Males, Nicholas B. Sepulveda, Donald Chen, Lisa N. Petrella

Biological Sciences Faculty Research and Publications

Moderate heat stress negatively impacts fertility in sexually reproducing organisms at sublethal temperatures. These moderate heat stress effects are typically more pronounced in males. In some species, sperm production, quality and motility are the primary cause of male infertility during moderate heat stress. However, this is not the case in the model nematode Caenorhabditis elegans, where changes in mating behavior are the primary cause of fertility loss. We report that heat-stressed C. elegans males are more motivated to locate and remain on food and less motivated to leave food to find and mate with hermaphrodites than their unstressed counterparts. …

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Characterizing Allosteric Regulation And Conformational Dynamics In Staphylococcus Aureus Pyruvate Carboxylase, Amanda Joan Laseke Oct 2023

Characterizing Allosteric Regulation And Conformational Dynamics In Staphylococcus Aureus Pyruvate Carboxylase, Amanda Joan Laseke

Dissertations (1934 -)

Pyruvate carboxylase (PC) produces oxaloacetate from pyruvate and bicarbonatein an ATP-dependent manner. The catalytic activity of PC places it at a pivotal intersection between catabolism and anabolism. Understanding the essential metabolic role of PC requires a more complete description of how its activity is regulated and how that regulation is manifested through changes in conformational dynamics. PC activity is regulated by the mutually exclusive binding of the allosteric activator, acetyl-CoA, and the allosteric inhibitor, L-aspartate. The binding site for acetyl- CoA has largely been identified, but the binding location for the acetyl moiety is unknown. Given that the acetyl moiety …

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