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2022

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Articles 31 - 60 of 1814

Full-Text Articles in Biology

Using Proteomics To Discover New Connections In The Arabidopsis Circadian Clock, Maria Lynn Sorkin Dec 2022

Using Proteomics To Discover New Connections In The Arabidopsis Circadian Clock, Maria Lynn Sorkin

Arts & Sciences Graduate Student Theses and Dissertations

The plant circadian clock is an endogenous timekeeping mechanism that uses daylength and temperature cycles to synchronize internal physiology with the external environment. Much of our understanding of the clock in the model plant Arabidopsis thaliana comes from genetic approaches. In this thesis, I use affinity purification coupled with mass spectrometry (APMS) to identify protein-protein interactions for core clock components on a proteomic scale. I developed and optimized a protocol to perform APMS on a core set of circadian clock proteins: CIRCADIAN CLOCK ASSOCIATED 1 (CCA1), LATE ELONGATED HYPOCOTYL (LHY), PSEUDORESPONSE REGULATOR 5 (PRR5), PRR7, PRR9, TIMING OF CAB 1 …

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Bioinformatics And Cancer Genomics Approaches To Advance Precision Medicine And Elucidate Tumor Mutational Landscapes, Kelsy Cotto Dec 2022

Bioinformatics And Cancer Genomics Approaches To Advance Precision Medicine And Elucidate Tumor Mutational Landscapes, Kelsy Cotto

Arts & Sciences Graduate Student Theses and Dissertations

Next-generation sequencing of DNA and RNA continues to be integrated into pre-clinical and clinical research. However, challenges still remain that impede the translation of findings into an improved understanding of human diseases or clinically actionable alterations. The projects described in this dissertation start with compiling efforts from experts who have identified druggable genes within the human genome, followed by in-depth analyses which characterize the pan-cancer landscape of splice-associated mutations and noncoding, regulatory mutations across multiple subtypes of breast cancer. In Chapters 2 and 3, substantial efforts were made to update the content and the user experience for the drug-gene interaction …

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Characterizing Complex Affective Processing Across Age And In Relation To Social Anxiety Symptoms, M. Catalina Camacho Dec 2022

Characterizing Complex Affective Processing Across Age And In Relation To Social Anxiety Symptoms, M. Catalina Camacho

Arts & Sciences Graduate Student Theses and Dissertations

Humans require a shared understanding of others’ emotions for adaptive social functioning. For instance, if someone tells a joke and another person laughs, we assume the laughing person was happy because we have a shared concept for such positive interactions. Children develop and refine these concepts as they grow up, but the underlying neural processing that supports this development is unknown. Identifying the neurodevelopment underlying emotion processing could provide important insight to emotional disorders. For example, social anxiety is associated differences in the detection and interpretation of negative or neutral emotional cues, but the underlying neurodevelopment of this behavior is …

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Host Development And Microbiota Influences On Norovirus Infection, Elizabeth Alexandra Kennedy Dec 2022

Host Development And Microbiota Influences On Norovirus Infection, Elizabeth Alexandra Kennedy

Arts & Sciences Graduate Student Theses and Dissertations

The mammalian gut is a complex organ which changes over the course of development and is influenced by the presence of a dense community of gut-resident microbes. Enteric viruses infect the gastrointestinal tract in the context of the commensal microbiota and host immunity. Here, we dissect the influence of host developmental stage and the gut microbiota in norovirus infection. From this work, we determine that murine norovirus (MNoV) infection in early life is restricted by an absence of the target MNoV cell tuft cells and intact interferon (IFN) signaling. However, viral inoculum taken up by non-specific endocytosis in the neonatal …

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Extensive Behavioral Phenotyping Of Williams Syndrome Locus Relevant Mouse Models To Assess Contributions Of Oxytocin And Gtf2ird1, Kayla Rose Nygaard Dec 2022

Extensive Behavioral Phenotyping Of Williams Syndrome Locus Relevant Mouse Models To Assess Contributions Of Oxytocin And Gtf2ird1, Kayla Rose Nygaard

Arts & Sciences Graduate Student Theses and Dissertations

The Williams Syndrome Critical Region (WSCR) at chromosome 7q11.23 provides a unique opportunity to untangle the relationship between genotype and phenotype in complex behaviors, from fear and anxiety to sociability and sensorimotor processing. Copy number variations (CNVs) in this region result in two syndromes, Williams Syndrome (WS) and Duplication 7q11.23 Syndrome (Dup7), which display phenotypes that may align, indicating a common disruption of a system, or diverge, reflecting an underlying gene dosage-dependent effect. While case studies of atypical deletions resulting in WS have implicated telomeric genes Gtf2ird1 and Gtf2i in the cognitive and behavioral profiles of WS, proving causation requires …

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Circadian Circuitry And Glioblastoma: Interactions With Behavior, Carcinogenesis, And Clinical Practice., Anna R. Damato Dec 2022

Circadian Circuitry And Glioblastoma: Interactions With Behavior, Carcinogenesis, And Clinical Practice., Anna R. Damato

Arts & Sciences Graduate Student Theses and Dissertations

Glioblastoma (GBM) is the most common primary adult brain tumor diagnosed, with a 15-month prognosis using current standard of care treatment which includes chemotherapy with temozolomide (Temodar, TMZ). Chronotherapy, the practice of considering time of day in treating a disease, has been shown to improve outcome in several cancers, but had not been applied to GBM. Previous work in the lab on a cultured murine mesenchymal GBM cell line showed a time-of-day dependent maximum in sensitivity to TMZ corresponding with the daily peak of Bmal1 and trough of Per2 expression, two core clock genes. Based on this finding, we sought …

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Sik3 & Wnk Signals Through Fray To Regulate Glial K+ Buffering And Seizure Susceptibility In Drosophila Models Of Hyperexcitability, Lorenzo Laronn Lones Dec 2022

Sik3 & Wnk Signals Through Fray To Regulate Glial K+ Buffering And Seizure Susceptibility In Drosophila Models Of Hyperexcitability, Lorenzo Laronn Lones

Arts & Sciences Graduate Student Theses and Dissertations

K+ homeostasis is important for maintaining healthy, physiological levels of neuronal activity. Glial cells play a central role in maintaining homeostatic ion gradients. In previous work from our lab, we unravel a glial K+ buffering program that is centered on a key kinase, salt-inducible kinase 3 (SIK3). SIK3-HDAC4 signaling in glial regulates the transcription of channels and transporters involved in water and ion transport. Defects in this pathway lead to peripheral nerve edema, neuronal hyperactivity, and seizure sensitivity. In an hyperexcitability mutant, eag Shaker, we show this pathway is downregulated and genetic activation suppresses seizure behavior. In this thesis, I …

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Emerging Insights Into A Role For Topoisomerase Iib And Methyl-Cpg Binding Protein 2 In Regulating Neuronal Transcription, Sabin Nettles Dec 2022

Emerging Insights Into A Role For Topoisomerase Iib And Methyl-Cpg Binding Protein 2 In Regulating Neuronal Transcription, Sabin Nettles

Arts & Sciences Graduate Student Theses and Dissertations

The mammalian brain has unparalleled diversity of cell types with distinct molecular, morphological, connectional and functional properties. The specialization of these cells occurs during development through a series of spatially and temporally controlled changes in gene expression that are critical for proper assembly and function. Neurons in particular have complex and elaborate gene regulatory systems which allow specific combinations of genes to be expressed at distinct levels and at discrete developmental stages, giving rise to heterogenous neuronal subtypes. Identifying unique neuronal gene regulatory factors that contribute to the dynamic changes in gene expression are critical to understanding the molecular mechanism …

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System Shock: Using -Omics Data To Characterize Biological Remodeling In The Microbiome, Resistome, And Transcriptome Of Bacteria, Winston Eugene Anthony Dec 2022

System Shock: Using -Omics Data To Characterize Biological Remodeling In The Microbiome, Resistome, And Transcriptome Of Bacteria, Winston Eugene Anthony

Arts & Sciences Graduate Student Theses and Dissertations

The human experience is indelibly linked to microbial life. So much so, that the holobiont theory has been coined to define the assemblage of host and microbe as a discrete ecological unit. Perturbation of the commensal microbiome can create niche space for pathogens, which through the concomitant rise of antimicrobial resistance represent an ever-evolving danger. In Chapter 2 of this dissertation, I describe the results of an interventional study designed to directly perturb the healthy gut microbiome and observe the dynamics of taxonomic composition and functional recovery. I observe significant decreases after 5 days of antibiotic treatment in the gold …

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Insights Into The Non-Osmoregulatory Function Of A Pollen-Specific Mechanosensitive Ion Channel, Kari Miller Dec 2022

Insights Into The Non-Osmoregulatory Function Of A Pollen-Specific Mechanosensitive Ion Channel, Kari Miller

Arts & Sciences Graduate Student Theses and Dissertations

Pollen, the male gametophyte of flowering plants, delivers the sperm cells to the ovule to carry out sexual reproduction. During this process, the pollen grain undergoes dramatic physical changes. Survival requires careful control of cell mechanics, particularly the balance between protoplast expansion and cell wall resistance. One control mechanism is the use of a mechanosensitive (MS) ion channel, MscS-Like (MSL)8. This pollen-specific protein was previously shown to be essential for pollen survival during hydration and was proposed to function as a tension-gated osmoregulator. However, direct proof of osmoregulation during initial hydration has not yet been found. In fact, studies of …

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Contributions Of Specific Retinal Circuits And Their Respective Projections To Visual Behaviors, Jenna Mackenzie Krizan Dec 2022

Contributions Of Specific Retinal Circuits And Their Respective Projections To Visual Behaviors, Jenna Mackenzie Krizan

Arts & Sciences Graduate Student Theses and Dissertations

The survival of a species is inextricably linked to its ability to successfully navigate and interact with its surroundings, whether to seek safety from predators or gain sustenance from prey. Both functions are performed by mice, guided by vision, and rely on intricate processing in the retina and subcortical targets in the brain. This dissertation addresses how specific features of the visual environment and specific retinal ganglion cell circuits that sample a particular space in the visual environment are used to guide efficient predation in mice.Recent studies have begun to link the ability to detect, track, and ultimately capture prey …

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The Impact Of Nucleolar Stress On Thymocyte Development And T Cell Acute Lymphoblastic Leukemia Transformation, Joseph Ryan Krambs Dec 2022

The Impact Of Nucleolar Stress On Thymocyte Development And T Cell Acute Lymphoblastic Leukemia Transformation, Joseph Ryan Krambs

Arts & Sciences Graduate Student Theses and Dissertations

Increased Notch signaling is thought to be central to T-ALL pathogenesis, with activatingmutations of NOTCH1 in 60% of cases, and Notch pathway activation due to mutations in FBXW7 in an additional 15% of cases. Increased Notch signaling results in markedly increased ribosome biogenesis, inducing a negative feedback loop called the nucleolar stress pathway. This is an evolutionarily conserved homeostatic pathway that is triggered by excessive ribosome biogenesis that serves to limit rRNA synthesis, protein translation, and ultimately cell growth. CDKN2A, encoding both ARF and INK4A, plays a key role in the nucleolar stress pathway. Activation of ARF and INK4A inhibits …

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Generation, Characterization, And Treatment Of Functional Zebrafish Models For Musculoskeletal Disorders, Julia Nicole Whittle Dec 2022

Generation, Characterization, And Treatment Of Functional Zebrafish Models For Musculoskeletal Disorders, Julia Nicole Whittle

Arts & Sciences Graduate Student Theses and Dissertations

Musculoskeletal disorders in humans present with a broad range of phenotypes that vary in severity, onset, and genetic cause. The musculoskeletal system is comprised of complex and diverse tissues that make up the majority of total body mass. Thus, mutations in many different genes with differing structure and function can produce phenotypically similar developmental and morphological defects in the muscle and skeleton. In addition, the muscular and skeletal systems develop non-autonomously, wherein development and function of each will affect development of the other. Thus, mutations in genes responsible for development of this complex system have the potential to influence morphogenesis …

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Single-Cell Massively Parallel Reporter Assays, Siqi Zhao Dec 2022

Single-Cell Massively Parallel Reporter Assays, Siqi Zhao

Arts & Sciences Graduate Student Theses and Dissertations

Our understanding of gene regulation needs to be generalizable as well as specific. A generalizable understanding enables us to transfer our knowledge of one gene to another, and the specificity allows us to understand the precise regulation of gene expression through development. One framework that confers generalizability and specificity is the hierarchical and modular model of gene regulation. To test whether gene regulation is hierarchical and modular requires methods to systematically analyze how different factors collectively control gene expression. This thesis describes the development of two functional genomics methods at single-cell resolution. These methods systematically examined how cellular contexts, chromatin …

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A Structural Perspective On Neutralizing Antibodies To Flaviviruses And Coronaviruses, John Michael Errico Dec 2022

A Structural Perspective On Neutralizing Antibodies To Flaviviruses And Coronaviruses, John Michael Errico

Arts & Sciences Graduate Student Theses and Dissertations

The presence of neutralizing antibodies typically correlates strongly with protection from infection, particularly for RNA viruses; elicitation of neutralizing antibody responses is thus the primary goal of most vaccines, and monoclonal antibodies (mAbs) can be leveraged as potent therapeutics. Thus, understanding the properties of individual antibodies that comprise polyclonal antibody responses and their epitopes is essential for countermeasure design. In this dissertation, I explore the epitopes and functional properties of monoclonal antibodies targeting the structural proteins of two families of RNA viruses, flaviviruses and coronaviruses.Flaviviruses are globally distributed arthropod-borne positive-sense RNA viruses transmitted primarily by either mosquitos or ticks. Symptomatic …

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The Effects Of Nmda Antagonism On Neuronal Activity And Neurovascular Coupling In Non-Human Primate Cortex, Benjamin Thomas Acland Dec 2022

The Effects Of Nmda Antagonism On Neuronal Activity And Neurovascular Coupling In Non-Human Primate Cortex, Benjamin Thomas Acland

Arts & Sciences Graduate Student Theses and Dissertations

The N-methyl-D-aspartate receptor (NMDAR) plays a variety of important roles in the development and function of primate central nervous systems. This thesis describes three nonhuman primate studies that, together, demonstrate that pharmacologically reducing NMDAR activity not only causes dramatic changes in neural activity in cortex, but also changes the relationship between that activity and a key signal often used as its proxy in human studies, the blood-oxygen-level-dependent (BOLD) signal. The first study reveals that NMDA antagonism is sufficient to induce powerful low-frequency modulation of spiking activity and extracellular local field potential (LFP) and discusses the implications of this finding for …

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Understanding Individual Cells In Zebrafish Caudal Fin Regeneration (从单细胞视角理解斑马鱼尾鳍再生历程), Yiran Hou Dec 2022

Understanding Individual Cells In Zebrafish Caudal Fin Regeneration (从单细胞视角理解斑马鱼尾鳍再生历程), Yiran Hou

Arts & Sciences Graduate Student Theses and Dissertations

Humans are incapable of complex body structure regeneration. Understanding how other species retain the ability to regenerate can help us to find solutions for improving our regenerative capacities. The zebrafish is an organism that is capable of regenerating multiple organs in its body. Using zebrafish as a model organism, previous studies have identified key processes and illustrated the crucial cell types and genes for regeneration. In caudal fin specifically, blastema formation is a key predictor of successful regeneration. However, a comprehensive molecular understanding of cell type-specific contributions to this process is lacking. In this dissertation, I present our efforts toward …

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Fructose Promotes The Growth Of Tumors Through Metabolite Exchange With Non-Malignant Tissues, Ronald Joseph Fowle-Grider Dec 2022

Fructose Promotes The Growth Of Tumors Through Metabolite Exchange With Non-Malignant Tissues, Ronald Joseph Fowle-Grider

Arts & Sciences Graduate Student Theses and Dissertations

The amount of dietary fructose consumed in the United States has increased considerably over the past five decades, largely due to the widespread use of high fructose corn syrup as a sweetener. The potential link between this elevated fructose intake and the development of cancer remains incompletely understood. Here we show that, even though cervical cancer cells themselves cannot directly utilize fructose carbon, diets high in fructose enhance the growth of cervical tumors by nearly threefold in mice. We demonstrate that efficient utilization of fructose carbon requires ketohexokinase-C, which was not expressed in ~100 cervical tumors that we examined from …

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Canonical And Noncanonical Mechanisms Of Resistance To Arginine Starvation In Cancer, Leonard Christopher Rogers Dec 2022

Canonical And Noncanonical Mechanisms Of Resistance To Arginine Starvation In Cancer, Leonard Christopher Rogers

Arts & Sciences Graduate Student Theses and Dissertations

The enzyme argininosuccinate synthetase 1 (ASS1) catalyzes the condensation of citrulline and aspartate into argininosuccinate as part of the urea cycle and citrulline-nitric oxide cycle. This reaction is essential for mammals to synthesize the amino acid arginine, which is required for all cells. Nearly all human tissues express at least some ASS1, but they import most of their arginine from the extracellular space after it is produced and released by the kidneys. Most solid tumors lack a functional level of ASS1, including over 85% of sarcomas, which are cancers of connective tissues. Published evidence suggests that this provides a proliferation …

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The Role Of The Neurodevelopmental Disorder Gene Myt1l In Mammalian Brain Development, Jiayang Chen Dec 2022

The Role Of The Neurodevelopmental Disorder Gene Myt1l In Mammalian Brain Development, Jiayang Chen

Arts & Sciences Graduate Student Theses and Dissertations

Recent human genetic studies have associated mutations in a gene called Myelin Transcription Factor 1 Like (MYT1L) with neurodevelopmental disorders (NDDs). Patients with MYT1L loss of function (LoF) mutations (MYT1L Syndrome patients) demonstrate shared symptoms such as microcephaly, attention deficit and hyperactivity disorder (ADHD), and obesity. Despite prior studies showing MYT1L overexpression facilitates neuronal differentiation in vitro, its functions in vivo, especially in the mammalian brain, and how its mutation leads to human disease pathology remains poorly understood. Here, I established the first mouse model of MYT1L Syndrome mimicking a patient specific LoF mutation. I found mice with Myt1l heterozygous …

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Tissue Resident Macrophages Drive Fibrosis During Pancreas Inflammatory Injury And Pancreatic Ductal Adenocarcinoma, John Baer Dec 2022

Tissue Resident Macrophages Drive Fibrosis During Pancreas Inflammatory Injury And Pancreatic Ductal Adenocarcinoma, John Baer

Arts & Sciences Graduate Student Theses and Dissertations

The immune system, and especially macrophages, are central in responding to infections, as well as providing a wide array of functions in other pathologies, especially in responding to inflammation. It is established that macrophages will accumulate within tissues during inflammation, many times secreting cytokines and chemokines central to the inflammatory response. This is particularly true during pancreatitis, or inflammation of the pancreas, where it has been shown that macrophages and monocytes accumulate in the pancreas to have various roles in further promoting inflammation. It is not well established, however, whether there are divergent roles for the distinct macrophage subsets that …

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Connections Between Mechanosensitive Ion Channel Msl10 And Er-Plasma Membrane Contact Sites, Jennette Marie Codjoe Dec 2022

Connections Between Mechanosensitive Ion Channel Msl10 And Er-Plasma Membrane Contact Sites, Jennette Marie Codjoe

Arts & Sciences Graduate Student Theses and Dissertations

Mechanosensitive (MS) ion channels are an evolutionarily conserved way for cells to sense mechanical forces and transduce them into ionic signals. A plasma membrane-localized MS channel from Arabidopsis thaliana, MscS-Like (MSL)10, senses cell swelling and initiates a signaling cascade that triggers programmed cell death. Whereas the channel properties of MSL10 have been well studied, how MSL10 signals remains largely unknown. I worked collaboratively to show that important lesions for cell death signaling in the cytosolic N- and C-terminal domains of MSL10 interact genetically. I also helped show that ionic flux through MSL10 is dispensable for signaling, which suggested that MSL10 …

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Analyzing The Interconnectedness Of The Human Genome, Nicholas Jacobs Dec 2022

Analyzing The Interconnectedness Of The Human Genome, Nicholas Jacobs

Arts & Sciences Graduate Student Theses and Dissertations

The human genome is much more interconnected than many people realize. In this thesis, I will outline two efforts to portray this idea. First, I will seek to display that cell fitness is an omniphenotype. That is to say, cell fitness can be used to determine whether an unknown factor interacts with a known factor for any phenotype. The human genome is sufficiently interconnected that if two factors interact with one another then that can be reflected by a multiplicative change in cell fitness. This change in fitness can be used to determine if a new factor of interest is …

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Cooperation And Conflict In The Social Amoeba Dictyostelium Discoideum And Its Paraburkholderia Endosymbionts, James Medina Dec 2022

Cooperation And Conflict In The Social Amoeba Dictyostelium Discoideum And Its Paraburkholderia Endosymbionts, James Medina

Arts & Sciences Graduate Student Theses and Dissertations

A big question in biology is how organisms compete in an environment of competitors for scarce resources. Part of the answer lies in distinguishing friend from foe and in forging cooperative bonds in the face of cheaters. The social amoeba – bacteria system I have studied here is an excellent place to explore these tensions. The first part of my thesis research involves a review of cooperation and conflict in the social amoeba Dictyostelium discoideum and a study of the limits on obligate social cheating in this species. The second part focuses on the benefits of associating with D. discoideum …

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Inferring Adaptation In Social Microbes From Experimental Evolution Under Relaxed Selection, Tyler John Larsen Dec 2022

Inferring Adaptation In Social Microbes From Experimental Evolution Under Relaxed Selection, Tyler John Larsen

Arts & Sciences Graduate Student Theses and Dissertations

Microbes exist against a backdrop of other organisms, and the interactions between microbes have major consequences on their traits, their evolution, and their impact on the world. Microbial interactions and the adaptations that enable them are extremely diverse – they can unlock abilities beyond the reach of individual cells or lead to a population’s destruction, they can be temporary or permanent, they can be between genetically identical cells or different species entirely. The first chapter of this dissertation reviews microbial interactions and the related concept of the evolution of conflict and cooperation.To be certain a trait is an adaptation at …

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The Enemy Within: An Investigation Of The Intracellular Bacteria In Urinary Tract Infections, Jennie Elizabeth Hazen Dec 2022

The Enemy Within: An Investigation Of The Intracellular Bacteria In Urinary Tract Infections, Jennie Elizabeth Hazen

Arts & Sciences Graduate Student Theses and Dissertations

Urinary tract infections (UTIs) are common diseases that are associated with significant morbidities. Multiple studies have indicated that multiple species of uropathogenesis bacteria invade and persist within bladder epithelial cells as a necessary step of uropathogenesis. Interestingly, many of these species are not canonically associated with intracellular infections. Although the first study describing bacteria within the urothelium was published two decades ago, this critical step of uropathogenesis remains relatively understudied.I established a murine model of community-acquired A. baumannii UTI, a previously unstudied manifestation of the disease. While immunocompetent mice resolved their infections quickly, immunocompromised mice displayed high bacterial burdens throughout …

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A Universal Mechanism Of G Protein Inhibition, Tyson Daniel Todd Dec 2022

A Universal Mechanism Of G Protein Inhibition, Tyson Daniel Todd

Arts & Sciences Graduate Student Theses and Dissertations

G protein coupled receptors transduce a truly staggering number of diverse extracellular signals including chemical messengers, physical force, and even photons into specific cellular responses through their coupling to heterotrimeric G proteins. G proteins amplify the originating signal through their binding to downstream effectors, activating a complex network of overlapping responses that allow the cell to respond perfectly to that specific stimulus. It is critical to the cell that this process is carried out faithfully in order to respond to the myriad environmental cues and avoid injury, exhaustion, and death for the individual cell or the development of pathology if …

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Genetic And Transcriptomic Aspects Of Major Depressive Disorder: In Vivo Functional Assays Of Risk-Associated Variation, Candidate Disease Cell Types, And Their Pharmacologic And Sex Interactions, Bernard Mulvey Dec 2022

Genetic And Transcriptomic Aspects Of Major Depressive Disorder: In Vivo Functional Assays Of Risk-Associated Variation, Candidate Disease Cell Types, And Their Pharmacologic And Sex Interactions, Bernard Mulvey

Arts & Sciences Graduate Student Theses and Dissertations

Major depressive disorder (MDD) is a debilitating illness that affects hundreds of millions globally, with substantial personal, medical, economic, and societal consequences. While depression occurs more commonly in females, the biology of the brain and sex underlying this skewed prevalence remains unclarified. This body of work explores two aspects of how biological sex may influence the brain at the level of gene expression: through intrinsic sex differences and through sex-mediated effects of depression risk genetics.The monoamine hypothesis of depression suggests that modulatory neurotransmitters including serotonin and norepinephrine constitute a key axis in development of MDD. Large-scale studies of MDD treatment …

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Mechanisms For High Light Tolerance In A Fast-Growing Cyanobacterium, Patricia Walker Dec 2022

Mechanisms For High Light Tolerance In A Fast-Growing Cyanobacterium, Patricia Walker

Arts & Sciences Graduate Student Theses and Dissertations

Through oxygenic photosynthesis, cyanobacteria, algae, and plants convert light into chemical energy. However, highly energetic light often damages the photosynthetic apparatus, which can lead to the decline of photosynthetic activity (photoinhibition), and prolonged photoinhibition can lead to cell death. Cyanobacteria enact various protective mechanisms to mitigate photodamage, many of which have been conserved in plants. Repair of PSII reaction centers, decreased light absorption, quenching of excess absorbed energy, and biosynthesis of antioxidants all work to mitigate damage during high light. Due to the adjustments to photosynthesis, acclimation to high light requires remodeling of cellular metabolism and physiology. Therefore, phototrophs have …

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Roles Of Behavioral Novelty And Organismal Energetics In The Evolution Of Extreme Encephalization, Erika Laurie Schumacher Dec 2022

Roles Of Behavioral Novelty And Organismal Energetics In The Evolution Of Extreme Encephalization, Erika Laurie Schumacher

Arts & Sciences Graduate Student Theses and Dissertations

Brains and their component brain regions vary widely in size and structure across vertebrates. However, extreme increases in total brain size relative to body size (extreme encephalization) and increases in specific major brain region sizes independent of other brain regions (mosaic brain evolution) are relatively rare. There are several hypotheses as to why, but the energetic cost of increased brain tissue and the regional interconnectedness in both brain development and function likely constrain how brains are able to change in response to selection. In this dissertation, I sought to address both how behavioral novelty relates to evolutionary changes in brain …

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