Developmental Biology Commons^™

Evolution And Development Of The Seed Coat In Gymnosperms, Cecilia Zumajo

Dissertations, Theses, and Capstone Projects

Gymnosperms and angiosperms are the most abundant plant lineages on earth and constitute a turning point in the evolution of plants because they are at the origin of the seed, a key morphological and developmental novelty in the evolution of land plant. Although the morphological variation of the seed, across seed plants, may on its own, explain the complexity of this structure, the origin, and evolution are even more, the understanding of these topics is still under discussion. Evidence shows that previous studies have often lacked the component of gene expression, particularly in species that are not model species. The …

Molecular Mechanisms Underlying Cell Fate Choice Within Specific Retinal Lineages, Estie Schick

Dissertations, Theses, and Capstone Projects

During development, retinal progenitor cells (RPCs) divide to form all of the cell types that make up the retina. Multipotent RPCs are competent to generate all retinal cell types, while restricted RPCs form specific lineages of cells. In particular, one genetically-defined RPC type preferentially gives rise to cone photoreceptors and horizontal cells. Many of the mechanisms that are responsible for directing cell fate choice within this lineage are unknown. This thesis largely focuses on examining the development of specific cell types and subtypes from restricted RPCs and on investigating the gene regulatory events that underlie cone photoreceptor and horizontal cell …

Characterizing The Gene Regulatory Network Required To Specify The Excitatory Neurotransmitter Phenotype Of V0v Spinal Interneurons, Amber Kellie Woodard

Theses - ALL

The majority of neurons within the spinal cord are interneurons. Interneurons make important connections with other cells that allow signals to be relayed between the brain and the rest of the body, and aid in functions such as locomotion. One key functional characteristic of interneurons is the neurotransmitter that they use to communicate with other cells. Interneurons that use GABA or glycine neurotransmitters to communicate have an inhibitory phenotype, while interneurons that use glutamate neurotransmitters have an excitatory neurotransmitter phenotype. Without the correct neurotransmitter phenotype, connections within the central nervous system will malfunction. It is therefore important to understand how …

Creating A Protein Chimera To Study Regulation Of Muscle Diversity, Shannon Scarboro

Symposium of Student Scholars

Creating a protein chimera to study regulation of muscle diversity.

Body muscles are made of many individual super-cells, called muscle fibers, that have distinct properties and determine every individual’s strength and endurance. Initially all muscle fibers have identical characteristics, but become differentiated into specific types in adults. The mechanism of such transition is not well understood, despite its obvious importance for shaping human physicality.

Remarkable conservation of the muscle tissue enables us to use fruit flies to study the mechanisms of muscle fiber diversity. We hypothesized that the transcription factor Mef2 acts as a molecular switch that activates structural genes …

The Effects Of Mapk Signaling On The Development Of Cerebellar Granule Cells, Kerry Morgan

University Scholar Projects

The granule cells are the most abundant neuronal type in the human brain. Rapid proliferation of granule cell progenitors results in dramatic expansion and folding of the cerebellar cortex during postnatal development. Mis-regulation of this proliferation process causes medulloblastoma, the most prevalent childhood brain tumor. In the developing cerebellum, granule cells are derived from Atoh1-expressing cells, which arise from the upper rhombic lip (the interface between the roof plate and neuroepithelium). In addition to granule cells, the Atoh1 lineage also gives rise to different types of neurons including cerebellar nuclei neurons. In the current study, I have investigated the …

The Effects Of Mapk Signaling On The Development Of Cerebellar Granule Cells, Kerry Morgan

Honors Scholar Theses

The granule cells are the most abundant neuronal type in the human brain. Rapid proliferation of granule cell progenitors results in dramatic expansion and folding of the cerebellar cortex during postnatal development. Mis-regulation of this proliferation process causes medulloblastoma, the most prevalent childhood brain tumor. In the developing cerebellum, granule cells are derived from Atoh1-expressing cells, which arise from the upper rhombic lip (the interface between the roof plate and neuroepithelium). In addition to granule cells, the Atoh1 lineage also gives rise to different types of neurons including cerebellar nuclei neurons. In the current study, I have investigated the …

In Utero And Postnatal Oxycodone Exposure: Implications For Intergenerational Effects, Katherine E. Odegaard

Theses & Dissertations

Prescription opioid abuse during and after pregnancy is a rising public health concern. Adding a layer of complexity is the role of heredity in the overall development of these exposed offspring. The present work uses a preclinical rat model mimicking oxycodone (oxy) exposure in utero (IUO) and postnatally (PNO) to investigate comparative and intergenerational effects in the two different exposure groups.

To understand the direct effects of IUO and PNO exposure on the F1 generation, we employed a systems biology approach encompassing proton magnetic resonance spectroscopy (¹H-MRS), electrophysiology RNA-sequencing, and pain assessment to elucidate molecular and behavioral changes …

Rna Modification Landscape And Its Contribution To Egg Production, Ian Thomas Rapisarda

Legacy Theses & Dissertations (2009 - 2024)

Germline stem cells differentiate into mature egg or sperm cells that go through the process of fertilization which gives rise to all sexually reproducing organisms. During this process of differentiation, germ cells undergo a switch from mitosis to meiosis that allows for proper development and specification of the future gamete. The mechanisms that facilitate this shift from mitosis to meiosis, however, are not well understood. To gain insight into this process, we used Drosophila oogenesis as our model. To identify what RNA modifications are present during oogenesis we genetically enriched for each stage of development and performed mass spectrometry. We …

Dynamics Of Hybrid Zones At A Continental Scale, Bradley T. Martin

Graduate Theses and Dissertations

Hybridization has traditionally been viewed as a happenstance that negatively impacts populations, but is now recognized as an important evolutionary mechanism that can substantially impact the evolutionary trajectories of gene pools, influence adaptive capacity, and contravene or reinforce divergence. Physiographic processes are important drivers of dispersal, alternately funneling populations into isolation, promoting divergence, or facilitating secondary contact of diverged populations, increasing the potential for hybridization. In North America, glacial-interglacial cycles and geomorphological changes have provided a dynamic backdrop over the last two million years that promoted such oscillations of population contraction and expansion. These biogeographic processes have resulted in regional …

Genetic Pathway Analysis Of Abnormal Facial Development In Nonsyndromic Cleft Lip And Palate, Lorena Maili

Dissertations and Theses (Open Access)

Nonsyndromic cleft lip with or without cleft palate (NSCLP) is the most common craniofacial birth defect resulting from incomplete fusion of the facial prominences during development, which leaves a gap in the lip, primary palate and/or the secondary palate. NSCLP affects 135,000 NSCLP newborns worldwide each year based on a birth prevalence of 1 per 700 live births. While surgical treatments have dramatically improved, many long-term health issues persist, imposing significant medical, psychosocial and economic burdens. Familial aggregation and segregation analyses suggest genetic contributions underlie NSCLP, but despite decades of study, only a small portion of the NSCLP genetic liability …

216— Loss Of Function Mutation For Tp53 Does Not Rescue The Chaf1bNt2 Small-Eye Phenotype In Danio Rerio, Alex Parks

GREAT Day Posters

In Zebrafish, the chromosome assembly factor 1b (chaf1b) gene is in part responsible for the development of the eye. In homozygous chaf1bt24412 mutants retinal cell death is promoted through cell-death promoting activity of the gene, tumor suppressor protein p53 (tp53), resulting in a small-eye phenotype. Another allele chaf1bnt2, was found to also result in the small-eye phenotype when in a homozygous state. We found that knockdown of Tp53 protein via morpholino antisense oligonucleotide injection of 1-2 cell stage embryos failed to rescue retinal cell death of chaf1bnt2 homozygous mutants as detected by TUNEL labeling. Because morpholinos may fail to fully …

Zebrafish (Danio Rerio) Hoxb6: An Exploration Into The Divergence Of Genomic Dna Sequence And Gene Expression Across Teleost Fishes Post-Genome Duplication, Amber Lynn Rittgers, Pierre Le Pabic, Adam Davis

Georgia Journal of Science

Hoxb6 is an evolutionarily conserved developmental regulatory gene that functions, in part, to pattern several organs and organ systems within the embryonic trunk during vertebrate embryogenesis. The cis-regulatory circuitry mediating trunk expression in mouse (Mus musculus) may be conserved across gnathostome vertebrates, as several other species show similar trunk expression patterns, including chicken (Gallus gallus), dogfish shark (Scyliorhinus canicula), and several teleost fishes. A whole genome duplication event that occurred in the lineage leading to teleost fishes has generated at least two Hoxb6 genes, hoxb6a and b6b. Two teleost fishes of the …

The Phoenix, Fernanda Perez-Alvarez

Montserrat Annual Writing Prize

This article uses a mythical creature, the phoenix, to examine and illustrate the biological principles for generation of an adult body plan from a single cell. Using the study of developmental biology, it explores the cellular and molecular biology that underpins the massive complexity of creating an adult body plan. It also explores the similarities and differences between different embryos, and how nature and evolution have shaped the biology of those embryos to create different body plans.

The Influence Of Autism Linked Gene Topoisomerase 3b (Top3b) On Neural Development In Zebrafish, Sydney Doolittle

Honors College Theses

Autism Spectrum Disorder is a class of developmental disabilities characterized by a spectrum of social, communication, and behavioral impairments in affected individuals. Studies have shown these defects stem from abnormal brain development during critical periods during early development. The underlying genetic cause of these impairments is not well understood but is believed to be a combination of a complex pairing of genetic and environmental factors. One of the genetic factors that has been recognized to influence the phenotypic symptoms of ASD is the enzyme topoisomerase 3β (top3β.) Topoisomerases are responsible for the prevention of supercoiling during DNA replication. Top3β is …

Development And Maintenance Of The Thymic Epithelial Microenvironment, Shami Chakrabarti

Dissertations, Theses, and Capstone Projects

The thymus plays a critical role in adaptive immunity by providing a suitable microenvironment for developing and selecting the functional self-tolerant T-cell population. Thymic epithelial cells play an essential role in the development of a naïve, self-tolerant T-cell population. Paradoxically thymus undergoes acute age-related involution, which in turn causes loss of functional T-cell populations. Involution reduces the functionality of the thymus markedly, but the thymus can still develop self-tolerant naïve T-cells. It is crucial to understand how the thymic microenvironment is maintained to provide a suitable T-cell population for life. It has been previously demonstrated that the thymic epithelial homeostasis …

Differentiating Human Embryonic Stem Cells In Micropatterns To Study Cell Fate Specification And Morphogenetic Events During Gastrulation, Kyaw Thu Minn

McKelvey School of Engineering Graduate Student Theses & Dissertations

During mammalian embryogenesis, the first major lineage segregation occurs when embryonic epiblast, and extraembryonic trophectoderm and hypoblast arise in the blastocyst. In the next fundamental and conserved phase of animal embryogenesis known as gastrulation, extraembryonic cells provide signals to epiblast to instruct embryonic patterning, and epiblast gives rise to germ layers ectoderm, mesoderm, and endoderm, that will establish all embryonic tissues. Proper specification and morphogenesis of germ layers during gastrulation is vital for correct embryonic development. Due to ethical and legal restrictions limiting human embryo studies, human gastrulation is poorly understood. Our knowledge of human gastrulation has largely been derived …

Cyclin-Dependent Kinase 1 And Aurora Kinase Choreograph Mitotic Storage And Redistribution Of A Growth Factor Receptor, C. D. Cota, M. S. Dreier , '20, W. Colgan, A. Cha, Twan Sia , '21, Bradley Justin Davidson , '91

Biology Faculty Works

Endosomal trafficking of receptors and associated proteins plays a critical role in signal processing. Until recently, it was thought that trafficking was shut down during cell division. Thus, remarkably, the regulation of trafficking during division remains poorly characterized. Here we delineate the role of mitotic kinases in receptor trafficking during asymmetric division. Targeted perturbations reveal that Cyclin-dependent Kinase 1 (CDK1) and Aurora Kinase promote storage of Fibroblast Growth Factor Receptors (FGFRs) by suppressing endosomal degradation and recycling pathways. As cells progress through metaphase, loss of CDK1 activity permits differential degradation and targeted recycling of stored receptors, leading to asymmetric induction. …

Characterization Of The Whale Shark (Rhincodon Typus) Melanocortin-2 Receptor, Brianne Hoglin

Electronic Theses and Dissertations

Among bony vertebrates, the melanocortin-2 receptor ortholog is unique among the family of five melanocortin receptors on the basis that it is dependent on its accessory protein, MRAP1, for trafficking and activation, and is selective for activation by ACTH alone. Previous studies on the MC2R orthologs of select cartilaginous fish, the elephant shark (Callorhinchus milii) and the red stingray (Dasyatis akajei), revealed divergent traits in a less obligatory relationship on MRAP1 and its ability to be activated by ACTH or the MSH-sized peptides. However, observed traits were not consistent between these two cartilaginous fish species, posing …

Rab35 Centered Membrane Trafficking Pathway Directs Apical Constriction During Drosophila Gastrulation, Hui Miao

Electronic Theses and Dissertations

Force generation in epithelial tissues is often pulsatile, with actomyosin networks generating high-tension contractile forces at the cell cortex before cyclically disassembling. This pulsed nature of cytoskeletal forces implies that there must be cellular processes to extract unidirectional changes that drive processive transformations in cell shape. During Drosophila melanogastergastrulation, the invagination of the prospective mesoderm is driven by the pulsed constriction of apical surfaces. Here, we address the mechanisms by which the irreversibility of pulsed events is achieved while also permitting uniform epithelial behaviors to emerge. We use MSD-based analyses to identify contractile steps and find that when a …

Mammalian Sec Proteins Expression And Purification, Elizabeth Bolton, Braden North, Brayden Vanderweide

Summer Research

Sec23 and Sec24 mammalian proteins assist in the transport of cargo proteins from the endoplasmic reticulum to the Golgi apparatus. These COP II coat proteins trap cargo proteins for transport, potentially with direct binding to cargo protein GLUT1.

The Characterization Of The Function(S) Of Crag In Basement Membrane Polarity, Hemin Pankajkumar Shah

Graduate Research Theses & Dissertations

The abundant epithelial cells play various roles in the development and maintenance of an organism, and their apical-basolateral polarity is a unique characteristic that is imperative to their function and integrity. This polarity is maintained via various environmental cues and tightly regulated intracellular trafficking, where the presence of the basement membrane (BM) provides a basal cue. The BM is a specialized extracellular matrix (ECM) secreted by the epithelial cells, which accumulates on the basal side and serves as their mechanical anchorage. Although the BM is of paramount importance in the apical-basolateral polarity and the loss of BM’s integrity is a …

Transactivation And Mitochondrial Activity Are Affected By High Temperature In C. Elegans Sperm, Jacqueline Mcvay

Scripps Senior Theses

Sexual reproduction has a conserved flaw in that it is temperature sensitive. Exposure to high temperature leads to male infertility, but little is known about the underlying mechanism. Understanding these mechanisms is important for agriculture and reproductive medicine. Using C. elegans, we investigated two potential aspects of male fertility that may be affected by high temperature conditions: activation of sperm by seminal fluid and sperm mitochondrial activity. There are two pathways for sperm activation in C. elegans: the SPE-8 pathway in hermaphrodites and the TRY-5 pathway in male seminal fluid. Hermaphrodite sperm with a mutation in spe-8 can …

Cop9 Signalosome Component Csn-5 Promotes Accumulation And Function Of Stem Cell Regulators Fbf-1 And Fbf-2, Emily Osterli

Graduate Student Theses, Dissertations, & Professional Papers

RNA-binding proteins FBF-1 and FBF-2 (FBFs) are required for stem cell maintenance in C. elegans, although the mechanisms by which FBFs protein levels are regulated remain unknown. Using a yeast two-hybrid screen, we identified an interaction between both FBFs and CSN-5, a component of the COP9 (constitutive photomorphogenesis 9) signalosome. This highly conserved COP9 complex can affect protein stability through a range of mechanisms including deneddylation, deubiquitination, and phosphorylation (Wolf et al., 2003). Mapping protein-protein interactions between FBFs and CSN-5 suggested that the MPN (Mpr1/Pad1 N-terminal) metalloprotease domain of CSN-5 interacts with the RNA-binding domain of FBFs at physiologically …

Periocular Mesenchyme Heterogeneity During Morphogenesis Of The Vertebrate Ocular Anterior Segment, Kristyn L. Van Der Meulen

Theses and Dissertations--Biology

The vertebrate eye is a complex organ, responsible for the primary sense with which we interact with our environment: vision. Development of the eye is a tightly regulated process, controlled by a vast network of genes. This process begins with eye morphogenesis, when the eye structure is formed through a series of morphogenetic movements and culminates in the creation of the optic cup, lens, and presumptive optic stalk. Next, retinal differentiation creates the critical cell layers of the retina needed to process light waves that enter the eye, including rod and cone photoreceptors, interneurons, and support cells. Failure in either …

Protocadherin-17 Expression And Function In Vertebrate Brain: A Literature Review, Mathea Mcguire

Williams Honors College, Honors Research Projects

For this project, I will be doing a systematic review on protocadherin-17 function in vertebrate brain development and function in the last 10 years. Protocadherins are members of cadherin superfamily. Cadherins are calcium-dependent cell adhesion molecules that are implicated to play crucial roles in the information and maintenance of tissues and organs in vertebrate animals. This review will summarize major findings regarding protocadherin-17 expression and function in major model organisms such as zebrafish and mice, as well as results from human studies. It is hoped that this work will be a valuable source for background knowledge of protocadherin-17 function in …

Molecular Mechanisms Regulating Optic Fissure Fusion During Zebrafish Eye Development, Megan Weaver

Theses and Dissertations--Biology

Vertebrate retinal development requires timely and precise fusion of the optic fissure. Failure of this event leads to congenital vision impairment in the form of coloboma. Recent studies have suggested hyaloid vasculature to be involved in OF fusion. In order to examine this link, we analyzed optic fissure fusion and hyaloid vasculogenesis in the zebrafish pax2a noi mutant line. We first determined that pax2a^-/- embryos fail to accumulate F-actin in the optic fissure prior to basement membrane (BM) degradation. Furthermore, using 3D and live imaging we observed reduced OF hyaloid vascularization in pax2a^-/- embryos. When examining the connection …

Leveraging Transcriptomic Approaches To Identify Differences In Genetic Programming Driving Two Distinct Wound Healing Mechanisms, Regeneration And Fibrosis, In Acomys And Mus, Shishir K. Biswas

Theses and Dissertations--Biology

Why can some animals and others cannot? This fundamental question has fueled scientists studying regeneration for hundreds of years since early observations in crayfish, salamanders and many other organisms. While most contemporary work in regeneration is done in a handful of species including salamanders, zebrafish and flatforms, these organisms lack a closely-related, non-regenerating sister species from which unique genetic differences can be identified. Additionally, while much has been learned from these organisms, they do not share fundamental biological traits with mammals (endothermy, metabolism and immune system) which limits the ability to translate this research for clinical medicine. To this end, …

Larval Anatomy Of Monotypic Painted Ant Nest Frogs Lithodytes Lineatus Reveals Putative Homoplasies With The Leptodactylus Pentadactylus Group (Anura: Leptodactylidae), Filipe A.C Do Nascimento, Rafael O. De Sá, Paulo C. De A. Garcia

Biology Faculty Publications

The morphological diversity of anuran larvae made them an important source of information for evolutionary and systematic studies. For the monotypic frog genus Lithodytes, which has an interesting taxonomic history, including its past synonymizing with Adenomera and its placement as a subgenus of Leptodactylus, the information provided from its larvae can help to understand its systematics interrelationships and also provide insights about its evolutionary trajectories. Herein, we provide a detailed description of the larval morphology of Lithodytes lineatus, including novel data of internal morphology (buccopharyngeal cavity and skeleton), and discuss some morphological and evolutionary aspects in relation …

Using Zebrafish To Elucidate The Expression And Gene Regulatory Network Of The Genomic Screen Homeobox Transcription Factors And Bring Innovative Science Learning Experiences To West Virginia, Rebecca Ann Coltogirone

Graduate Theses, Dissertations, and Problem Reports (ETD)

Central nervous system (CNS) development requires a code of regionally expressed transcription factors that impart initial neuronal cell identity, connectivity, and function. The absence of a transcription factor code would eliminate the neurodevelopmental logic producing diverse cell types in the CNS. Furthermore, early disruptions in transcription factor expression can affect later connectivity and function of neuronal circuits mediating sensory processing, defects in which are often observed as comorbid with various neurodevelopmental disorders (NDDs). Characterizing transcription factor expression and function is therefore an essential step in discerning the molecular mechanisms underlying human NDDs. genomic screen homeobox 1 and 2 (gsx1 …

Microrna In The Mammalian Growth Plate: Matrix Vesicles And 1Α,25-Dihydroxyvitamin D3, Niels C. Asmussen

Theses and Dissertations

Growth plate chondrocytes are the driving force of long bone elongation and they accomplish this vital task, in part, by producing, remodeling, and finally mineralizing the cartilage tissue that makes up the growth plate. This mineralized tissue is turned over again as bone forming cells invade and began the process of turning mineralized cartilage into bone. Chondrocytes undergo a distinct series of observable phases as they move through this process transitioning from a stage of proliferation to one of hypertrophy and finally capillary invasion. Chondrocytes produce matrix vesicles (MVs) that they release into the growth plate and that attach to …