Biology Commons^™

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 …

Improving Cold Tolerance Of Asian Rice Through Plant Growth Promoting Bacteria And Rice Gene Manipulation: Mechanisms Of Pseudomonas Mosselli And Osmads27, Nasim Maghboli Balasjin

Dissertations (1934 -)

It is estimated that by the year 2050, the human population will extend to 9.7 billion and therefore the demand for food will increase. It is important to find ways to maintain production of critical crops, like rice, to match the demand. Climate change affects crop productivity as it is the reason for extreme warm or cold weather fluctuations. Asian rice (Oryza sativa L.) generally is grown in tropical and subtropical regions and thus, is sensitive to cold temperatures. This study hypothesized two strategies could improve growth and cold tolerance of rice plants: (1) use of plant growth promoting bacteria …

Figures 1 And S3, Tayler D. Sheahan, Amanpreet Grewal, Laura E. Korthauer, Edward M. Blumenthal

Sheahan 2023

Confocal Z-series .nd2 files (Nikon NIS) showing GFP fluorescence from dissected egg chambers. These files were used to create the maximum intensity projections displayed in figure 1 (UAS-GFPnls drd-gal4 stage 10B and 14 10.27.16.nd2) and figure S3 (UAS-GFPnls drd-gal4 stage 14 7.16.21.nd2 and UAS-GFPnls control stage 14 7.16.21.nd2). Files with “UAS-GFPnls drd-gal4” were experimental samples containing both the drd-GAL4 and UAS-GFP.nls transgenes, while files with “UAS-GFPnls control” were controls lacking the drd-GAL4 transgene. The “10.27.16” and “7.16.21” file sets were imaged on different days with different settings, so image intensities should not be compared between the two file sets.

Nuclear And Cytoplasmic Spatial Protein Quality Control Is Coordinated By Nuclear–Vacuolar Junctions And Perinuclear Escrt, Emily M. Sontag, Fabián Morales-Polanco, Jian-Hua Chen, Gerry Mcdermott, Patrick T. Dolan, Dan Gestaut, Mark A. Le Gros, Carolyn Larabell, Judith Frydman

Biological Sciences Faculty Research and Publications

Effective protein quality control (PQC), essential for cellular health, relies on spatial sequestration of misfolded proteins into defined inclusions. Here we reveal the coordination of nuclear and cytoplasmic spatial PQC. Cytoplasmic misfolded proteins concentrate in a cytoplasmic juxtanuclear quality control compartment, while nuclear misfolded proteins sequester into an intranuclear quality control compartment (INQ). Particle tracking reveals that INQ and the juxtanuclear quality control compartment converge to face each other across the nuclear envelope at a site proximal to the nuclear–vacuolar junction marked by perinuclear ESCRT-II/III protein Chm7. Strikingly, convergence at nuclear–vacuolar junction contacts facilitates VPS4-dependent vacuolar clearance of misfolded cytoplasmic …

Altered Motivation & Dopamine Subcircuit Plasticity Unique To Sex During Protracted Opioid Withdrawal, Devan Marc Gomez

Dissertations (1934 -)

Opioid use disorder (OUD) is associated with enduring psychological withdrawal symptoms believed to contribute to drug abuse. Amongst these are shifts in motivational states, wherein pursuit of drug consumption exceeds that of non-drug rewards, reinforcing escalated opioid use and relapse vulnerability. A critical regulator of behavioral reinforcement, the mesoaccumbal dopamine system is thought to be both necessary and sufficient for opioid motivation. However, previous research into its involvement in opioid withdrawal has been limited to acute rather than protracted timepoints, global neuroadaptations rather than those in subcircuits, and overwhelmingly focused on males over females. Using a rodent model of self-administration …

Targeted Mapping Of Oryza Sativa Chilling Tolerance Candidate Genes Using Multiple Stress-Relevant Quantitative Traits, Naoki Simon Shimoyama

Dissertations (1934 -)

Developing chilling tolerant accessions of domesticated Asian rice is a potential source of significant crop improvement to address the needs of a growing global population. The uniquely chilling sensitive nature of the tropically originating Oryza sativa make it the most important staple crop that could gain the maximum benefit from improved tolerance to low temperature stress. However, mechanisms underlying this complex trait are not fully understood. Oryza sativa has two major varietal groups with different levels of chilling tolerance, JAPONICA and INDICA, providing an ideal tool to investigate mechanistic differences in the chilling stress tolerance responses within this important crop …

Postnatal Developmental Trends In Membrane Excitability And Bk Channel Function In The Rodent Hippocampus, Michael S. Hunsberger

Dissertations (1934 -)

This dissertation outlines the postnatal development of excitability as well as expression and function of BK potassium channels in hippocampal neurons. I used patch clamp electrophysiology to measure how neuronal action potential waveforms and action potential firing frequencies change in early development, and how pharmacological blockade of BK channels affects these properties in hippocampal neurons. I also describe how the protein expression of the BK channel pore-forming α subunit and mRNA expression of different variants of the pore forming α subunit and auxiliary beta-4 subunit changes with development. I demonstrate in both cultured rat hippocampal neurons across the first seven …

Evidence That The Inner Nuclear Membrane Is A Functional Β1-Adrenergic Receptor Signaling Platform In Astrocytes, Kelsey Benton

Dissertations (1934 -)

The noradrenergic system exerts powerful modulatory influences over fundamental brain processes including attention, arousal, learning, and memory by activating adrenergic receptors on neuronal and glial cells. In addition to triggering rapid, transient changes in cellular physiology that drive short-term behavioral actions, these G-protein-coupled receptors also initiate delayed, long-lasting changes in cellular function by regulating gene expression. For example, in astrocytes, norepinephrine-induced activation of β-adrenergic receptors (β-ARs) rapidly induces glucose mobilization from glycogen stores, while simultaneously initiating delayed changes in the expression of glycogen storage genes. Regulation of gene expression requires adrenergic receptor-initiated intracellular signals to reach the nuclear compartment. To …

Phase Separation In Biology And Disease; Current Perspectives And Open Questions, Steven Boeynaems, Shasha Chong, Jörg Gsponer, Liam Holt, Dragomir Milovanovic, Diana M. Mitrea, Oliver Mueller-Cajar, Bede Portz, John F. Reilly, Christopher D. Reinkemeier, Benjamin R. Sabari, Serena Sanulli, James Shorter, Emily M. Sontag, Lucia Strader, Jeanne Stachowiak, Stephanie C. Weber, Michael R. White, Huaiying Zhang, Markus Zweckstetter, Shana Elbaum-Garfinkle, Richard Kriwacki

Biological Sciences Faculty Research and Publications

In the past almost 15 years, we witnessed the birth of a new scientific field focused on the existence, formation, biological functions, and disease associations of membraneless bodies in cells, now referred to as biomolecular condensates. Pioneering studies from several laboratories supported a model wherein biomolecular condensates associated with diverse biological processes form through the process of phase separation. These and other findings that followed have revolutionized our understanding of how biomolecules are organized in space and time within cells to perform myriad biological functions, including cell fate determination, signal transduction, endocytosis, regulation of gene expression and protein translation, and …

Figure 1, Marquette University, Lisa N. Petrella

Mikeworth 2023

No abstract provided.

Figure 2, Marquette University, Lisa N. Petrella

Mikeworth 2023

No abstract provided.

Figure 4, Marquette University, Lisa Petrella

Mikeworth 2023

No abstract provided.

Figure 5, Marquette University, Lisa Petrella

Mikeworth 2023

No abstract provided.

Figure 3, Marquette University, Lisa Petrella

Mikeworth 2023

No abstract provided.

Figure S2, Marquette University, Lisa Petrella

Mikeworth 2023

No abstract provided.

Figure S1, Marquette University, Lisa Petrella

Mikeworth 2023

No abstract provided.

Identification Of A Cis-Sex Chromosome Transition In Banded Geckos (Coleonyx, Eublepharidae, Gekkota), Shannon E. Keating, Eli Greenbaum, Jerry D. Johnson, Tony Gamble

Biological Sciences Faculty Research and Publications

Sex-determination systems are highly variable amongst vertebrate groups, and the prevalence of genomic data has greatly expanded our knowledge of how diverse some groups truly are. Gecko lizards are known to possess a variety of sex-determination systems, and each new study increases our knowledge of this diversity. Here, we used RADseq to identify male-specific markers in the banded gecko Coleonyx brevis, indicating this species has a XX/XY sex-determination system. Furthermore, we show that these sex-linked regions are not homologous to the XX/XY sex chromosomes of two related Coleonyx species, C. elegans and C. mitratus, suggesting that a cis- …

Experimental And Observational Evidence Of Negative Conspecific Density Dependence In Temperate Extomycorrhizal Trees, Fiona V. Jevon, Dayna De La Cruz, Joseph A. Lamanna, Ashley K. Lang, David A. Orwig, Sydne Record, Paige V. Kouba, Matthew P. Ayres, Jaclyn H. Matthes

Biological Sciences Faculty Research and Publications

Conspecific negative density dependence (CNDD) promotes tree species diversity by reducing recruitment near conspecific adults due to biotic feedbacks from herbivores, pathogens, or competitors. While this process is well-described in tropical forests, tests of temperate tree species range from strong positive to strong negative density dependence. To explain this, several studies have suggested that tree species traits may help predict the strength and direction of density dependence: for example, ectomycorrhizal-associated tree species typically exhibit either positive or weaker negative conspecific density dependence. More generally, the strength of density dependence may be predictably related to other species-specific ecological attributes such as …

Ontogeny Of The Paraphalanges And Derived Phalanges Of Hemidactylus Turcicus (Squamata: Gekkonidae), Aaron H. Griffing, Tony Gamble, Aaron M. Bauer, Anthony P. Russell

Biological Sciences Faculty Research and Publications

Gekkotan lizards of the genus Hemidactylus exhibit derived digital morphologies. These include heavily reduced antepenultimate phalanges of digits III and IV of the manus and digits III–V of the pes, as well as enigmatic cartilaginous structures called paraphalanges. Despite this well-known morphological derivation, no studies have investigated the development of these structures. We aimed to determine if heterochrony underlies the derived antepenultimate phalanges of Hemidactylus. Furthermore, we aimed to determine if convergently evolved paraphalanges exhibit similar or divergent developmental patterns. Herein we describe embryonic skeletal development in the hands and feet of four gekkonid species, exhibiting a range of …

The Ventral Hippocampus Dynamically Regulates Amygdala Encoding And Learned Fear, Matthew Richard Herbst

Dissertations (1934 -)

The nervous system has evolved a set of survival circuits optimized to respond to environmental threats. Adaptive threat responding requires learning to predict when and where a threat may occur based on available cues. Such learning depends on a distributed network of brain structures, but there is much we do not understand about how these brain areas interact to support fear memory. Addressing this gap is crucial for understanding anxiety- and fear-related disorders as dysfunction in fear learning networks is implicated in the development and persistence of pathological fear states. In my dissertation work, I used a rodent model of …

Explore The Regulatory Roles Of Micrornas In Sperm Formation And Function Of C. Elegans, Lu Lu

Dissertations (1934 -)

Gene regulation mediated by microRNAs (miRNAs) at the post-transcriptional level is important for producing functional sperm in diverse species including C. elegans. However, the specific regulatory roles of miRNAs in this process are largely unknown. The central goal of my dissertation is to address this question. I proposed to study the function of miRNAs enriched in male gonads, which are approximately 95% germ cells and 5% somatic cells. I isolated adult gonads of males and hermaphrodites for small RNA sequencing and the analysis revealed a differential miRNA expression profile between hermaphrodite and male gonads. 29 male gonad-enriched miRNAs have the …

Investigations Into The Negative Impact Of Temperature Stress On Fertility In Wild Strains Of Caenorhabditis Elegans, Nicholas B. Sepulveda

Dissertations (1934 -)

Sexual reproduction and its coincident genetic recombination are powerful adaptive strategies. However, sexual reproduction has disadvantages. One ancient and conserved disadvantage is temperature sensitivity. In organisms diverse as plants, insects, nematode worms, and humans, as temperatures increase, fertility decreases. The goal of this dissertation is to examine the negative impact of elevated temperature stress on fertility in sexually reproducing organisms using wild strains of Caenorhabditis elegans. C. elegans presents a unique opportunity to study these effects broadly in two contexts, as worms may be either self-fertile hermaphrodites that produce both egg and sperm or males which produce only sperm. In …

Somatostatin Regulates Circadian Clock Function And Photic Processing, Deborah A. M. Joye

Dissertations (1934 -)

Daily and seasonal rhythms are programmed by neural circuits that use daily timing and duration of light to anticipate predictable environmental changes (i.e., day length, temperature, food, predation). Daily and annual changes in light modulate human health to produce both positive and negative effects, but neural mechanisms underlying light-driven changes in the brain remain poorly understood. In mammals, light is processed and encoded by the brain’s central clock, the suprachiasmatic nucleus (SCN). The SCN also encodes day length (i.e., photoperiod) to regulate annual fluctuations in mammalian physiology, but it’s not clear precisely how the SCN network achieves this. One signal …

Genome-Wide Identification Of The A20/An1 Zinc Finger Proteon Family Genes In Ipomoea Batatas And Its Two Relatives And Function Analysis Of Ibsap16 In Salinity Tolerance, Hao Xie, Qiangqiang Yang, Xiaoxiao Wang, Michael Schläppi, Hui Yan, Meng Kou, Wei Tang, Xin Wang, Yungang Zhang, Qiang Li, Shaojun Dai, Yaju Liu

Biological Sciences Faculty Research and Publications

Stress-associated protein (SAP) genes—encoding A20/AN1 zinc-finger domain-containing proteins—play pivotal roles in regulating stress responses, growth, and development in plants. They are considered suitable candidates to improve abiotic stress tolerance in plants. However, the SAP gene family in sweet potato (Ipomoea batatas) and its relatives is yet to be investigated. In this study, 20 SAPs in sweet potato, and 23 and 26 SAPs in its wild diploid relatives Ipomoea triloba and Ipomoea trifida were identified. The chromosome locations, gene structures, protein physiological properties, conserved domains, and phylogenetic relationships of these SAPs were analyzed systematically. Binding motif analysis of IbSAPs indicated that …

Thank You For Biting: Dispersal Of Beneficial Microbiota Through 'Antagonistic' Interactions, C.G.B. Grupstra, Nathan P. Lemoine, Chelsea N. Cook, Adrienne M.S. Correa

Biological Sciences Faculty Research and Publications

Multicellular organisms harbor populations of microbial symbionts; some of these symbionts can be dispersed through the feeding activities of consumers. Studies of consumer-mediated microbiota dispersal generally focus on pathogenic microorganisms; the dispersal of beneficial microorganisms has received less attention, especially in the context of 'antagonistic' trophic interactions (e.g., herbivory, parasitism, predation). Yet, this 'trophic transmission' of beneficial symbionts has significant implications for microbiota assembly and resource species (e.g., prey) health. For example, trophic transmission of microorganisms could assist with environmental acclimatization and help resource species to suppress other consumers or competitors. Here, we highlight model systems and approaches that have …

Caloric Restriction Prevents Obesity- And Intermittent Hypoxia-Induced Cardiac Remodeling In Leptin-Deficient Ob/Ob Mice, Aaron A. Jones, Sarah N. Framnes-Deboer, Arianne Shipp, Deanna M. Arble

Biological Sciences Faculty Research and Publications

Background:

Intermittent hypoxia (IH), a key characteristic of obstructive sleep apnea, is independently associated with cardiometabolic impairment. While endogenous leptin levels may provide cardioprotective effects against hypoxia, leptin resistance is common among obese individuals presenting with obstructive sleep apnea.

Methods:

Here, we assessed left ventricle (LV) function using M-mode echocardiography in lean wild-type, calorically-restricted ob/ob, and obese ob/ob mice before and after 6 days of IH to determine how obesity and intermittent hypoxia interact to affect cardiac function independent of leptin signaling.

Results:

Calorically-restricting ob/ob mice for 4 weeks prior to IH exposure prevented weight gain (−2.1 ± 1.4 …

Diversity Of Reptile Sex Chromosome Evolution Revealed By Cytogenetic And Linked-Read Sequencing, Ze-Xian Zhu, Kazumi Matsubara, Foyez Shams, Jason Dobry, Erik Wapstra, Tony Gamble, Stephen D. Sarre, Arthur Georges, Jennifer A. Marshall Graves, Qi Zhou, Tariq Ezaz

Biological Sciences Faculty Research and Publications

Reptile sex determination is attracting much attention because the great diversity of sex-determination and dosage compensation mechanisms permits us to approach fundamental questions about mechanisms of sex chromosome turnover. Recent studies have made significant progress in better understanding diversity and conservation of reptile sex chromosomes, with however no reptile master sex determination genes identified. Here we describe an integrated genomics and cytogenetics pipeline, combining probes generated from the microdissected sex chromosomes with transcriptome and genome sequencing to explore the sex chromosome diversity in non-model Australian reptiles. We tested our pipeline on a turtle, two species of geckos, and a monitor …

Conformational Selection Governs Carrier Domain Positioning In Staphylococcus Aureus Pyruvate Carboxylase, Joshua H. Hakala, Amanda J. Laseke, Anya Lei Koza, Martin St. Maurice

Biological Sciences Faculty Research and Publications

Biotin-dependent enzymes employ a carrier domain to efficiently transport reaction intermediates between distant active sites. The translocation of this carrier domain is critical to the interpretation of kinetic and structural studies, but there have been few direct attempts to investigate the dynamic interplay between ligand binding and carrier domain positioning in biotin-dependent enzymes. Pyruvate carboxylase (PC) catalyzes the MgATP-dependent carboxylation of pyruvate where the biotinylated carrier domain must translocate ∼70 Å from the biotin carboxylase domain to the carboxyltransferase domain. Many prior studies have assumed that carrier domain movement is governed by ligand-induced conformational changes, but the mechanism underlying this …

Embryology Of The Gekkota: Insights Into The Evolution An Development Of Morphological Diversity, Aaron Harp Griffing

Dissertations (1934 -)

Understanding the patterns and processes which result in morphological diversity is a central goal of evolutionary developmental biology or evo-devo. This diversity encompasses morphologies which have evolved numerous, independent times within a clade (evolutionary convergence) and others which have evolved only once within a clade (i.e. evolutionary novelty). Though many of these diverse morphologies exhibit functional capabilities and are intertwined with the ecology and diversification of the evolutionary lineage in question, their origins are largely unknown. Robust phylogenic analysis, genomic information, and detailed developmental data are critical lines of evidence to explain the evolutionary and ontogenetic origins of morphological novelty …

Vegetative Phenologies Of Lianas And Trees In Two Neotropical Forests With Contrasting Rainfall Regimes, Jose A. Medina-Vega, S. Joseph Wright, Frans Bongers, Stefan A. Schnitzer, Frank J. Sterck

Biological Sciences Faculty Research and Publications

• Among tropical forests, lianas are predicted to have a growth advantage over trees during seasonal drought, with substantial implications for tree and forest dynamics. We tested the hypotheses that lianas maintain higher water status than trees during seasonal drought and that lianas maximize leaf cover to match high, dry-season light conditions, while trees are more limited by moisture availability during the dry season.
• We monitored the seasonal dynamics of predawn and midday leaf water potentials and leaf phenology for branches of 16 liana and 16 tree species in the canopies of two lowland tropical forests with contrasting rainfall regimes in …