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Theses and Dissertations

Theses/Dissertations

2023

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Full-Text Articles in Life Sciences

Effect Of Timing Of Energy Intake On Blood Glucose And Body Composition In Women With Overweight Or Class One Obesity, Michael Wade Smith Dec 2023

Effect Of Timing Of Energy Intake On Blood Glucose And Body Composition In Women With Overweight Or Class One Obesity, Michael Wade Smith

Theses and Dissertations

Overweight and obesity has increased in the U.S. Unfortunately, this increases the risk of metabolic dysfunction, such as diabetes. Meal timing has recently shown promise as viable options to minimize the risk of overweight or obesity and metabolic dysfunction. The primary purpose of this study, therefore, was to investigate the effect of timing of energy intake on blood glucose in females with overweight or class one obesity (BMI=27-35 kg/m2). This study utilized crossover design with two conditions counterbalanced in random order. Participants completed two 2-week 1500kcal dietary interventions: 1) a big breakfast diet or BB (50% of energy intake between …


Investigating The Impact Of Transcription On Mutation Rates, Sarah Patterson Dec 2023

Investigating The Impact Of Transcription On Mutation Rates, Sarah Patterson

Theses and Dissertations

tRNA genes are highly transcribed and perform one of the most fundamental cellular functions. Although a universal pattern observed across all three domains of life is that highly transcribed genes tend to evolve slowly, tRNA genes have been shown previously to evolve rapidly. This rapid sequence evolution could result from relaxed selection, increased mutation rate, or a combination of both. Here, we use mutation-accumulation line sequencing data to show that tRNA genes accumulate more mutations than other gene types. Our results indicate that this elevated mutation rate is a consequence of both elevated transcription-associated mutagenesis and a lack of transcription-coupled …


Paternal Programming: The Role Of Seminal Plasma In Pregnancy Hemodynamics And Offspring Growth, Rebecca Michele Swanson Dec 2023

Paternal Programming: The Role Of Seminal Plasma In Pregnancy Hemodynamics And Offspring Growth, Rebecca Michele Swanson

Theses and Dissertations

Seminal plasma is commonly known to serve as a transport medium for sperm as it moves through the female reproductive tract for fertilization, however, more recent evidence demonstrates seminal plasma induces an expansive inflammatory response in the uterus. Murine models have found this inflammatory response is important for clearing pathogens and poor-quality sperm, eliciting the secretion of cytokines, chemokines, and embryokines that aid in embryo attachment and growth, placental angiogenesis, and blunting maternal immunity to the embryo. However, there is minimal research on the impacts of seminal plasma uterine priming in bovine, and more specifically embryo growth, uterine blood flow, …


Evaluating Selected Properties Of Underutilized Hardwood Species For Fabrication Of Cross-Laminated Timber Industrial Mats, Mercy Itunu Ogunruku Dec 2023

Evaluating Selected Properties Of Underutilized Hardwood Species For Fabrication Of Cross-Laminated Timber Industrial Mats, Mercy Itunu Ogunruku

Theses and Dissertations

Softwood is more in demand than hardwood because it is used primarily in the US's largest wood-consuming industry, construction, resulting in increased importation of softwood annually to meet this demand. Hardwood, used for non-structural purposes like furniture and interior designs, is more abundant in US forests. However, some hardwood species are underutilized and undervalued. Cross-laminated timber (CLT) has increased the demand for softwood.

A study evaluated the mechanical and physical properties of three underutilized hardwood species (321 yellow poplar, 393 sweetgum, and 262 red oak specimens) for CLT industrial mat manufacturing. The results showed that red oak had a higher …


Insights Into The Challenges Posed By Climate Change And Land Competition To Brazil’S Midwest Pulpwood Market, Roberto Hajime Sant Anna Kimura Dec 2023

Insights Into The Challenges Posed By Climate Change And Land Competition To Brazil’S Midwest Pulpwood Market, Roberto Hajime Sant Anna Kimura

Theses and Dissertations

I investigated the effect of climate change in one of the few expanding markets in the world in Brazil. In the last decades the demand for pulpwood increased from zero to 11 million tons, leading to an expansion of 700 thousand hectares of Eucalyptus plantation. In 2024, a new mill will start operating increasing the consumption of wood fiber by 8.2 million tons (+49%). I used mathematical programming to investigate how different scenarios of productivity and land will affect the market. My results showed that around 946,000 hectares (+124%) of additional timberland will be necessary in the upcoming decades. The …


Habitat Utilization Of Marsh And Adjacent Submerged Landscape By Fish And Macroinvertebrates In A Gulf Of Mexico Tidal Oligohaline Environment, Tia Offner Dec 2023

Habitat Utilization Of Marsh And Adjacent Submerged Landscape By Fish And Macroinvertebrates In A Gulf Of Mexico Tidal Oligohaline Environment, Tia Offner

Theses and Dissertations

Estuarine habitats are considered nursery habitats for fishes and invertebrates, but oligohaline environments are critically understudied. Using a seine net and fyke nets, we sampled Back Bay, Mississippi (USA), a low salinity estuary, once a month for a year to explore the temporal use of the marsh and adjacent submerged landscape by nekton species. We also looked at whether there is evidence of habitat preference in the most numerous nekton species. We used a novel habitat usage index (HUI) to compare seine and fyke net catches of our top 10 species, and evaluated catch size in relation to maturation size. …


Towards Understanding The Interactions Between Ospreys And Human-Made Structures In The Tennessee River Valley, Natasha Karina Murphy Dec 2023

Towards Understanding The Interactions Between Ospreys And Human-Made Structures In The Tennessee River Valley, Natasha Karina Murphy

Theses and Dissertations

Raptor nests on human-built structures represent a significant source of conflict as they can result in bird mortality, fires, structure damage, service distribution, or power outages when falling nest materials or animals connect with energized conductors. Power companies, such as the Tennessee Valley Authority (TVA), wish to mitigate these conflicts to avoid service disruptions. In this dissertation, I present my work towards understanding and mitigating the interactions between Ospreys (Pandion haliaetus) and human-made structures. To achieve this, I explored multiple elements of conflict identification, monitoring, and basic ecology of the target species to better inform conflict mitigation. In Chapter I, …


The Effects Of Intermittent Fasting On Female Athletes: A Systematic Review, Courtnie Scarbrough Dec 2023

The Effects Of Intermittent Fasting On Female Athletes: A Systematic Review, Courtnie Scarbrough

Theses and Dissertations

The intermittent fasting diet has a historical past, but recently, it has regained popularity as a weight loss strategy for the general public. Athletes have also picked up this specialized diet in search of a competitive edge. There are ample studies testing athletes of all levels, but most do not include females or report sex-specific results. This systematic review aimed to identify current research on the effects of intermittent fasting in the understudied population of female athletes. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a comprehensive search was conducted in three databases, including PubMed, Cochrane, …


The Influence Of At-Planting Insecticide Treatments On Tobacco Thrips, (Thysanoptera:Thripidae), And Reniform Nematode, (Tylenchida:Hoplolaimidae), In Conventional And Thryvon Cotton Systems, Walker Brett Farmer Dec 2023

The Influence Of At-Planting Insecticide Treatments On Tobacco Thrips, (Thysanoptera:Thripidae), And Reniform Nematode, (Tylenchida:Hoplolaimidae), In Conventional And Thryvon Cotton Systems, Walker Brett Farmer

Theses and Dissertations

One of the objectives of this research was to evaluate the need for an additional imidacloprid seed treatment on ThryvOn® (Bayer Crop Science®, St. Louis, MO) cotton to effectively manage tobacco thrips, Frankliniella fusca (Hinds). While evaluating thrips densities and damage ratings, ThryvOn cotton continued to display reduced damage and thrips populations than non-ThryvOn. Thrips populations and damage ratings were consistently reduced when incorporating a higher rate of imidacloprid, but they were not reduced enough to justify the higher rates of imidacloprid. Another objective of this research was to evaluate the impact of aldicarb (AgLogic Chemical® …


Effects Of Supplementing Sources Of Zinc On Digestibility Parameters Of Beef Steers, Arminda Spikes James Dec 2023

Effects Of Supplementing Sources Of Zinc On Digestibility Parameters Of Beef Steers, Arminda Spikes James

Theses and Dissertations

Zinc (Zn) has numerous functions and life sustaining processes depend on the presence of Zn within the body. Zinc sulfate is a common form of Zn supplemented in the beef industry. Inorganic sulfate based minerals have been associated with negative rumen effects, mainly, decreased rumen fermentation and protozoa numbers. Our studies concluded no difference in digestibility of three different forms of Zn (zinc glycinate, zinc sulfate, and zinc hydroxychloride). Although overall digestibility did not change, there were specific mineral concentration differences after steers consumed concentrate treatment for 10 days. These differences implied that the mineral fed was consumed and absorbed …


Moisture Effects On Visible Near-Infrared And Mid-Infrared Soil Spectra And Strategies To Mitigate The Impact For Predictive Modeling, Francis Hettige Chamika Anuradha Silva Dec 2023

Moisture Effects On Visible Near-Infrared And Mid-Infrared Soil Spectra And Strategies To Mitigate The Impact For Predictive Modeling, Francis Hettige Chamika Anuradha Silva

Theses and Dissertations

Instrumental disparities and soil moisture are two of the key limitations in implementing spectroscopic techniques in the field. This study sought to address these challenges through two objectives. The first objective was to assess Visible-near infrared (VisNIR) and mid-infrared (MIR) spectroscopic approaches and explore the feasibility of transferring calibration models between laboratory and portable spectrometers. The second objective addressed the challenge of soil moisture and its impact on spectra. The portable spectrometers demonstrated comparable performance to their laboratory-based counterparts in both regions. Spiking with extra-weight, was the most effective calibration transfer method eliminating disparities between instruments. The samples were rewetted …


Characterizing Stress Granule Regulation By Pas Kinase, Ataxin-2 And Ptc6 And Investigating The Lifespan Of Covid-19 Virus On Currency, Colleen R. Newey Dec 2023

Characterizing Stress Granule Regulation By Pas Kinase, Ataxin-2 And Ptc6 And Investigating The Lifespan Of Covid-19 Virus On Currency, Colleen R. Newey

Theses and Dissertations

The protein Ataxin-2 is a known positive regulator of stress granules in humans, mice and yeast (known as yeast PBP1). Due to the role that stress granules play in diseases including Amyotrophic Lateral Sclerosis (ALS) and cancer, this thesis investigates the role of Ataxin-2 and its protein binding partners in stress granule development and its effects on various metabolic phenotypes of the cell. PAS kinase is a sensory protein kinase, conserved from yeast to man, which regulates respiration and lipid biosynthesis. Our lab discovered that PAS kinase phosphorylates and activates Ataxin-2 in yeast, and that PAS kinase overexpression enhances localization …


Use Of Microcalorimetry To Evaluate Hardening Reactions In Protein Bars During Accelerated Storage, Tiffany Rose Spackman Dec 2023

Use Of Microcalorimetry To Evaluate Hardening Reactions In Protein Bars During Accelerated Storage, Tiffany Rose Spackman

Theses and Dissertations

Protein bars have become a popular option among consumers to increase protein content in their diets. Since there is a large market for protein bars, many factors must be considered when creating a protein bar that both satisfies consumers and has a long shelf-life. Hardening and textural changes in protein bars are some of the most common modes of shelf-life failure in this product category. When the typical product creation timeline from formulation to launch can be as short as 3-6 months and with added pressure from executives to quickly launch another new product afterwards, product development scientists simply do …


Soil Health In American Sports Fields, Miria C. Barnes Dec 2023

Soil Health In American Sports Fields, Miria C. Barnes

Theses and Dissertations

Healthy soils are essential for sustaining the world's ecosystems and maintaining human lifestyles. The adoption of biological, chemical, and physical analyses to assess soil health is a relatively new concept with a paucity of scientific work assessing how these metrics are affected by field management in urban systems Soil samples (n = 110) were collected from a diverse range of sports fields and, for comparative purposes, golf courses, farm fields, non-sport urban, undisturbed forest, and non-vegetated sandy soils. The samples were then analyzed using biological, chemical, and physical metrics to determine if there were significant differences between sport/golf venues and …


Novel Fire And Herbivory Regime Impacts On Forest Regeneration And Plant Community Assembly, Devri A. Tanner Dec 2023

Novel Fire And Herbivory Regime Impacts On Forest Regeneration And Plant Community Assembly, Devri A. Tanner

Theses and Dissertations

Human activities are increasing the occurrence of megafires that have the potential to alter the ecology of forest ecosystems. The objective of this study was to understand the impact of a 610 km2 megafire on patterns of forest regeneration and herbivory of three forest types (aspen/fir, oak/maple, and pinyon/juniper) within the burn scar. Sapling density, meristem removal, and height were measured across a transect network spanning the area of the burn scar over three years from 2019-2021. The network consisted of 17 burned/unburned transect pairs in adjacent burned/unburned forest stands (6 aspen/fir, 5 oak/maple, and 6 pinyon/juniper). Species that regenerated …


Biomolecular Function From Structural Snapshots, Roshanak Etemadpour Dec 2023

Biomolecular Function From Structural Snapshots, Roshanak Etemadpour

Theses and Dissertations

Biological molecules can assume a continuous range of conformations during function. Near equilibrium, the Boltzmann relation connects a particular conformation's free energy to the conformation's occupation probability, thus giving rise to one or more energy landscapes. Biomolecular function proceeds along minimum-energy pathways on such landscapes. Consequently, a comprehensive understanding of biomolecular function often involves the determination of the free-energy landscapes and the identification of functionally relevant minimum-energy conformational paths on these landscapes. Specific techniques are necessary to determine continuous conformational spectra and identify functionally relevant conformational trajectories from a collection of raw single-particle snapshots from, e.g. cryogenic electron microscopy (cryo-EM) …


Methodology To Investigate Protein-Protein Interactions Of Jun During Neuronal Differentiation Of Pc12 Cells, Heather L. Leskinen Dec 2023

Methodology To Investigate Protein-Protein Interactions Of Jun During Neuronal Differentiation Of Pc12 Cells, Heather L. Leskinen

Theses and Dissertations

In humans and other mammals, injury to the central nervous system (CNS) can cause a permanent loss of neuronal function, leading to cognitive defects, limb paralysis, and other neurological disabilities. In contrast, studies have shown that some non-mammalian vertebrates like zebrafish, have the remarkable ability to functionally regenerate axons after CNS injury by reactivating and sustaining the expression of regeneration-associated genes (RAGs). Some RAGs encode transcriptional regulators that dimerize to control downstream gene expression necessary for functional axonal recovery. Our lab has previously identified Jun as an important transcriptional regulator of regeneration after optic nerve injury in zebrafish. After axon …


Potential Moderating Impact Of Circulating Endocannabinoids On Resting State Networks And Post-Traumatic Stress Disorder, Emily Anne Albertina Dec 2023

Potential Moderating Impact Of Circulating Endocannabinoids On Resting State Networks And Post-Traumatic Stress Disorder, Emily Anne Albertina

Theses and Dissertations

Introduction: Traumatic injury increases risk for long-term adverse outcomes such as the development of post-traumatic stress disorder (PTSD). Research has found that risk for the development of PTSD after such an injury varies depending on individuals’ race/ethnic group and sex. Although prior work has explored relationships between injury and PTSD in these groups utilizing imaging paradigms (e.g., resting state functional connectivity) and biological paradigms (e.g., the endocannabinoid system), the relationship between these factors has been understudied. The present study explored the potential moderating effect circulating endocannabinoids may have on the relationship between resting state functional connectivity and post traumatic stress …


Elucidating Aposematic Patterns In North American Hylids, Joseph S. Cannizzaro Iv Dec 2023

Elucidating Aposematic Patterns In North American Hylids, Joseph S. Cannizzaro Iv

Theses and Dissertations

Recognizing form and function of animal defenses is paramount to understanding the ecological and evolutionary forces behind predator and prey dynamics. Color patterns are strongly related to defensive strategies in animals. Some rely on camouflage to avoid detection, while others are brightly colored and conspicuously signal their noxiousness to potential predators. Still others combine cryptic dorsal coloration with colorful patches that are concealed in resting position but are facultatively unveiled by special behavior or simply during activity. Such hidden conspicuous color patches may be an intermediate stage in the evolution from camouflage to aposematism. We investigated whether conspicuously colored thighs …


Effects Of Short-Term Pesticides Exposure On Swimming Behavior, Tissue Morphology, Oxidative-Nitrative Stress, Antioxidant Expression, And Cellular Apoptosis In Kidneys Of Goldfish, Esmirna Cantú Dec 2023

Effects Of Short-Term Pesticides Exposure On Swimming Behavior, Tissue Morphology, Oxidative-Nitrative Stress, Antioxidant Expression, And Cellular Apoptosis In Kidneys Of Goldfish, Esmirna Cantú

Theses and Dissertations

The prevalence of pesticides in the aquatic environment continues to increase due to anthropogenic activities and poses a threat to aquatic organisms. The aim of this study was to determine the short-term exposure (one-week) of pesticide mixtures (metolachlor, linuron, isoproturon, tebucanazole, alconifen, atrazine, pendimethalin; azinphos-methyl) on swimming behaviors, kidney morphology, and expression of nitrotyrosine protein (NTP), dinitrophenyl protein (DNP), superoxide dismutase (SOD), catalase (CAT), renin, and cellular apoptosis in goldfish (Carassius auratus). Results indicated that both low- and high-dose pesticide mixtures decreased the distance swimming behavior. Histological analysis showed pesticide exposure alters kidney morphology. DNP, NTP, and renin expressions, and …


Overexpression Of Ubtf Correlates With Aggressive Phenotypes Of Prostate Cancer Cells, Guillermo Andres Saldana Dec 2023

Overexpression Of Ubtf Correlates With Aggressive Phenotypes Of Prostate Cancer Cells, Guillermo Andres Saldana

Theses and Dissertations

Prostate cancer (PrCa) is one of the most common malignancies in men globally and the second leading cause of cancer associated deaths in developed countries. Accumulating evidence have demonstrated involvement of various molecular and cellular factors in the development, progression and chemoresistance of PrCa and many of them were successfully established as potential molecular targets for therapy. Despite these advancements, the underlying mechanisms of PrCa occurrence is still unclear, which limits the diagnosis and therapy. Therefore, it is an urgent need to discover potential molecular targets which can be used in rational design of new strategies for the prevention and …


Growth Rates, Morphology, And Potential For Mariculture Of The Southern Population Of Crassostrea Virginica In The Lower Laguna Madre, Texas, Jerad Lee Fuelling Dec 2023

Growth Rates, Morphology, And Potential For Mariculture Of The Southern Population Of Crassostrea Virginica In The Lower Laguna Madre, Texas, Jerad Lee Fuelling

Theses and Dissertations

The Eastern Oyster also known as Crassostrea virginica, is an important resource here in the United States. Historically, this species has been overfished, poorly managed, and plagued by disease. Oyster mariculture is a growing industry here in the United States and is a sustainable solution to producing oysters. Texas has become the last coastal state to legalize oyster mariculture which means there is now a vast coastline with many unique bay systems that are open to this industry. One bay system that is particularly unique is the Lower Laguna Madre which is a hypersaline lagoon. Little is known about …


Monitoring The Effectiveness Of Wildlife Exits And Bobcat Use Along A South Texas Highway, Jamie E. Langbein Dec 2023

Monitoring The Effectiveness Of Wildlife Exits And Bobcat Use Along A South Texas Highway, Jamie E. Langbein

Theses and Dissertations

Roadside exclusion fencing is commonly used to mitigate wildlife road mortalities and property damages caused by wildlife-vehicle collisions. A potential consequence is that animals may become trapped on the road by fencing. On State Highway 100 in South Texas, the Texas Department of Transportation installed ten wildlife exits (WE) allowing animals to exit the roadway through a modified opening in the fence. However, some individuals used the WE to access the roadway. In this study, a new design was implemented, with narrower openings, a ramp and a clear plastic one-way door. While the updated design prevented road access for wildlife, …


Aedes Aegypti Host Preference On Canines Versus Human Volatile Skin Compounds, Melissa Bernadette Rosalez Dec 2023

Aedes Aegypti Host Preference On Canines Versus Human Volatile Skin Compounds, Melissa Bernadette Rosalez

Theses and Dissertations

It is critical to understand how Aedes aegypti mosquitoes detect hosts through cues such as volatile skin compounds. In South Texas, evidence suggests that this mosquito is showing a feeding preference for canines over humans. This shift may impact the transmission of Dirofilaria immitis, canine heart worms, in local dog populations. Our study is set to explore Ae. Aegypti attraction to hosts using canine and human volatile compounds. Volatile skin compounds will be collected using a volatile collection system. Compounds will be analyzed using gas chromatography/mass spectrometry. It is anticipated that the main volatile skin compounds amongst humans are nonanal, …


Chemical Investigation Of Dichloromethane Extract Of Aloe Vera Peels: An Agricultural Waste, Nazmul Huda Dec 2023

Chemical Investigation Of Dichloromethane Extract Of Aloe Vera Peels: An Agricultural Waste, Nazmul Huda

Theses and Dissertations

Aloe barbadensis Miller, commonly called Aloe Vera, is a widely popular succulent plant species cultivated across subtropical regions worldwide from India to the Tex-Mex border. Besides its historical uses, Aloe juice has garnered attention as a potential remedy for various ailments, particularly in treating various skin conditions and facilitating wound recovery, including obesity, diabetes, hepatitis, Crohn's disease, and ulcerative colitis. Regrettably, the agricultural practice following sap extraction involves discarding Aloe vera peels, constituting agricultural waste. As part of our continuous research on extraction, isolation, separation, and spectral characterization of value-added chemicals present in waste botanicals herein, …


The Relationship Between Biofouling Adhesion And Frequency Of Mechanical Cleaning To Control The Recruitment To Clear Coatings, Dylan Thomas Eggers Dec 2023

The Relationship Between Biofouling Adhesion And Frequency Of Mechanical Cleaning To Control The Recruitment To Clear Coatings, Dylan Thomas Eggers

Theses and Dissertations

There is a need to control biofouling on sensors and transparent windows in the marine environment. Clear silicone coatings offer a method to reduce the adhesion strength of marine organisms to the surface, however, these also require mechanical cleaning to maintain the surfaces free of fouling. This research evaluated the performance of eighty seven formulations and took the top two candidates to investigate a) the frequencies of wiping required by a brush to maintain two coatings and uncoated glass surfaces free of fouling and b) the effects of clear silicone coatings fouling release properties on required frequencies. The panels were …


Rage In Chronic Pulmonary Inflammation And Obstetric Complications, Katrina Lynn Curtis Nov 2023

Rage In Chronic Pulmonary Inflammation And Obstetric Complications, Katrina Lynn Curtis

Theses and Dissertations

The receptor for advanced glycation end-products (RAGE) is a transmembrane cell surface protein of the immunoglobulin superfamily that acts as part of both the innate and adaptive immune system. RAGE is highly expressed in lung tissue and is therefore of interest in the pulmonary immune response. Specifically, RAGE mediates several cell-signaling responses such as inflammation and apoptosis. This work sought to elucidate the role of RAGE in the setting of chronic pulmonary irritation such as that found in long-term exposure to secondhand smoke (SHS). This irritation has several shared characteristics with lung diseases such as chronic obstructive pulmonary disease (COPD) …


Elucidating The Architecture Of The Tclijn Complex That Converts Cysteine To Thiazoles In The Biosynthesis Of Micrococcin, Diana G. Calvopina Chavez Nov 2023

Elucidating The Architecture Of The Tclijn Complex That Converts Cysteine To Thiazoles In The Biosynthesis Of Micrococcin, Diana G. Calvopina Chavez

Theses and Dissertations

Thiopeptides are a family of antimicrobial peptides that are characterized for having sulfur-containing heterocycles, and for being highly post-translationally modified. Numerous thiopeptides have been identified; almost all of which inhibit protein synthesis in gram-positive bacteria. These intrinsic antimicrobial properties make thiopeptides promising candidates for the development of new antibiotics. The antimicrobial peptide micrococcin is a thiopeptide that is synthesized by the ribosome and undergoes several post-translational modifications (PTMs). Micrococcin is formed from a precursor peptide, TclE. TclE comprises an N-terminal leader (35-AA) that is crucial for recognition of the PTM machinery, alongside a C-terminal core sequence (14-AA) that undergoes multiple …


Manipulating And Assaying Chromatin Architecture Around Enhancer Elements In Vivo, John Lawrence Carter Nov 2023

Manipulating And Assaying Chromatin Architecture Around Enhancer Elements In Vivo, John Lawrence Carter

Theses and Dissertations

There are about 20,000 genes in the human genome. The lowly nematode worm, C. elegans, has about the same number of genes. How could two organisms that are so different arise from a similar number of genes? The answer is epigenetics, or the factors that help control when and where genes are expressed. There are many layers that comprise the epigenetic control of genes. One of which is the structure or architecture of chromatin. Chromatin is a complex of DNA and proteins. Histone proteins with DNA wrapped around them form the fundamental component of chromatin, the nucleosome. Chromatin exists in …


Evolutionary Conservation And Times Of Action Of Heterochronic Genes, Maria Ivanova Nov 2023

Evolutionary Conservation And Times Of Action Of Heterochronic Genes, Maria Ivanova

Theses and Dissertations

The heterochronic pathway of C. elegans is the most well-characterized system to date for controlling the sequence and timing of developmental events. However, we still have critical unanswered questions to address. First, little is known about the evolution of the heterochronic pathway, and of developmental timing in general. To determine if the roles of major heterochronic genes are conserved, I made mutants in orthologs of these genes in C. briggsae, using CRISPR/Cas9. My studies revealed a significant drift in the roles of some of the genes, although all of them are still involved in the developmental timing regulation, and several …