Life Sciences Commons^™

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

Arts & Sciences Electronic 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 …

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

Arts & Sciences Electronic 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 …

Dysregulation Of Gene Expression In Non-Photosensitive Trichothiodystrophy, Brittany Townley

Arts & Sciences Electronic Theses and Dissertations

The pre-mRNA life cycle requires intron processing; yet, how intron processing defects influence splicing and gene expression is unclear. Here, we find TTDN1, which is frequently mutated in non-photosensitive trichothiodystrophy (NP-TTD), functionally links intron lariat processing to the spliceosome. The conserved TTDN1 C-terminal region directly binds lariat debranching enzyme DBR1, while its N-terminal intrinsically disordered region (IDR) binds the intron binding complex (IBC). The IDR forms condensates in vitro and is needed for IBC interaction. TTDN1 loss causes significant intron lariat accumulation, as well as splicing and gene expression defects, mirroring phenotypes observed in NP-TTD patient cells. Ttdn1∆/∆ mice recapitulate …

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

Arts & Sciences Electronic 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 …

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

Arts & Sciences Electronic 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 …

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

Arts & Sciences Electronic 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 …

Overcoming Genetic Heterogeneity In Glioblastoma By Targeting Transcriptional Dependencies, Tatenda Mahlokozera

Arts & Sciences Electronic Theses and Dissertations

Glioblastoma (GBM) is the most common intrinsic central nervous system malignancy in adults, accounting for approximately 45% of such cancers. Despite advances in chemo- and radiotherapeutic approaches for various malignancies over the past decade, GBM remains an incurable disease with a dismal prognosis. Even after treatment with the current standard of care, which consists of maximal safe surgical resection, radiotherapy, and both concomitant and adjuvant chemotherapy with temozolomide, median survival is only approximately 17 months. Both treatment failure and difficulties in developing novel targeted therapies for GBM have partly been attributed to the molecular and cellular inter- and intra-tumoral heterogeneity …

Sex Differences In Cancer Metabolism Contribute To Sex-Specific Treatment Responses, Jasmin Inge Sponagel

Arts & Sciences Electronic Theses and Dissertations

Many human diseases show sex differences in incidence, age of onset, and outcome, including autoimmune diseases, neurological diseases, psychiatric disorders, cardiovascular diseases, metabolic diseases, neurodevelopmental disorders, and cancer. For most cancers, incidence and mortality rates are higher in males. Lung and brain cancers are no exception. Overall, lung cancer is more common in males. Furthermore, mortality rates of non-small cell lung cancer (NSCLC), the most common subtype of lung cancer, are significantly higher in males. The underlying reasons for sex differences in NSCLC mortality rates are largely unknown. Most brain cancers are also more common in males. The male prevalence …

The Maintenance Of Cd4 And Cd8 T Cell Response To Persistent Antigens, Yu Xia

Arts & Sciences Electronic Theses and Dissertations

In response to transient antigen presence in the context of acute infections or vaccinations, antigen-specific naïve T cells clonally expand and differentiate. Most of the expanded cells undergo terminally differentiation and die following antigen clearance to re-establish immune homeostasis. In contrast, when the pathogen persists, such as in the context of chronic viral infections or anti-tumor immunity, while T cells undergo alternative differentiation known as exhaustion due to their reduced functionality, T cells still contribute to pathogen control and its response is sustained for longer duration due to unknown mechanisms. The goal of my thesis work is to understand how …

Multi-Omics Investigation Of Tumor Heterogeneity, Oncogenic Signaling, And Treatment Response In Human Cancers, Yige Wu

Arts & Sciences Electronic Theses and Dissertations

Cancer is a highly complex disease with aberrations at the genetic, epigenetic, transcriptomic, and protein levels that drove its phenotypic diversity. Clear cell renal cell carcinoma (ccRCC) is the most common form of kidney cancer, comprising roughly 80% of cases. To define the epigenetic and transcriptomic regulation of ccRCC at the single nucleus (sn) level, we performed snRNA-seq and snATAC-seq in 34 and 28 samples respectively, including primary tumors and normal adjacent tissues, and matched them with bulk proteogenomics data. We identified tumor-specific markers and tumor subpopulations using snRNA-seq, which demonstrated diverse pathway activity within and across patients. PBRM1 and …

Understanding The Influence Of Individual-Level Sources Of Pathology Variation On Neuroimaging Measures Of Alzheimer Disease, Austin Andrew Mccullough

Arts & Sciences Electronic Theses and Dissertations

The overall goal of this dissertation is to gain a better understanding of how current Alzheimer disease pathologic progression models interact with sources of individual-level variation in pathology to influence overall disease progression in a clinically meaningful way. Many sources of variation, both internal (e.g., genetic mutations, heterogeneity of tau pathology) and external (e.g., diet and exercise, sleep quality), are known to influence disease progression and symptom onset in AD. With the advent of therapies that have shown successful reduction of amyloid load in trials and the rapid progression of anti-tau therapies, we hypothesize that a better understanding of how …

Macrophage Proliferation Machinery Drives Immunosuppression And Pdac Progression (巨噬细胞增值机制抑制肿瘤免疫促进胰腺癌发展), Chong Zuo

Arts & Sciences Electronic Theses and Dissertations

Tumor-associated macrophages (TAMs) are abundant in near all solid tumors and are involved in many aspects of cancer progression. The presence of TAMs is negative prognostic indicator in several cancer types including pancreatic cancer. Attempts to target this population by limiting their number in PDAC tumors have not achieved promising results, as compensatory resistance pathways have already been defined. The heterogeneity of TAMs puts another barrier into this targeting strategy, given macrophage subsets are important in maintaining tissue homeostasis and some in performing anti-tumor functions. Previous studies have shown that TAMs in PDAC tumors have dual origins – HSC-derived and …

Determinants Of Dna Damage Responses During B Cell Development, Rachel Leigh Johnston

Arts & Sciences Electronic Theses and Dissertations

Cellular DNA is regularly threatened by both physiologic (normal cellular mechanisms) and genotoxic (external exposures, such as irradiation and chemotherapy) insults. DNA double- stranded breaks (DSBs) are the greatest risk to the genome as they present opportunities for errant repair as mutations or translocations. To minimize these risks, DSBs activate highly conserved signaling pathways to coordinate cell cycle arrest, cell death and DNA repair. During normal development, B cells intentionally create site-specific chromosomal DSBs to assemble the immunoglobulin receptor (Ig) genes necessary for specific responses to pathogens. These programmed DNA breaks are generated by the recombinase activating gene (RAG) complex, …

Antigen Presentation In Central Nervous System Antitumor Immunity, Jay Aaron Bowman-Kirigin

Arts & Sciences Electronic Theses and Dissertations

Glioblastoma multiforme (GBM) patients face limited treatment options and poor outcomes. The median survival is less than two years, and there are no FDA approved immune therapies. Although GBM itself is an immune-suppressive, heterogeneous tumor, the lack of FDA approved immune therapies might be in part because the cancer immunity cycle is less well understood for GBM than for other tumor types. My studies focused on developing mouse models of malignant glioma that more faithfully recapitulate human GBM from an immunologic perspective, and on defining the role of the conventional dendritic cell 1 subset (cDC1) and lymphatic drainage in central …

Techniques For Spatial Analysis Of C. Elegans Anatomy And Reporter Expression, Nicolette Marie Laird

Arts & Sciences Electronic Theses and Dissertations

Quantitative analysis of microscopy images is integral to investigating biological phenomena. Despite a variety of tools to aid in analyzing C. elegans images, quantitative microscopy studies are still difficult due to the flexible and deformable nature of the nematode. These differences in posture and shape must first be corrected before analysis. Manual approaches to solve these problems are time intensive and infeasible for large datasets. Additionally, current automated tools rely on high-magnification imaging using labeled nuclei as fixed markers for comparison. Labelling can be achieved either with transgenic animals or fluorescent dyes; however, both of these can be impractical for …

T Cell Regulation Of Regenerative Environment In Acellular Nerve Allograft Repaired Peripheral Nerves, Deng Pan

Arts & Sciences Electronic Theses and Dissertations

Peripheral nerve injury (PNI) is common and has debilitating long term sequelae. Development of new therapies to improve regeneration following PNI is therefore critical. Acellular nerve allografts (ANAs) are increasingly utilized in the clinic for the repair of PNI and an improved mechanistic understanding of nerve regeneration through ANA is important for developing better therapies. Inflammation is an important aspect of regeneration, and the role of macrophage has been increasingly documented. Other aspect of inflammation has not been well-defined. In particular, there is limited understanding on the role of T cells in the regeneration of peripheral nerve. However, evidence in …