Developmental Biology Commons^™

Characterizing The Ethanol Sensitivity Of The Planar Cell Polarity Pathway In Endoderm Morphogenesis And Jaw Development., Raéden Omneil C. C. Rolle Gray

Electronic Theses and Dissertations

Fetal Alcohol Spectrum Disorders (FASD) describes a large range of developmental defects due to prenatal alcohol exposure. It is characterized by neural and facial defects, including jaw hypoplasia. Many factors contribute to the susceptibility of ethanol-induced facial defects, including genetics, yet the genes involved, and the cell events they regulate, are poorly understood. Zebrafish have a large number of tools for genetic manipulation available, share 70% of genes with humans, are fertilized externally and are translucent during embryogenesis, making them great models to study FASD. Previous studies show that two members of the Planar Cell Polarity (PCP) pathway, zebrafish vangl2 …

Ontogenetic Analysis Of Parasaurolophus Braincases (Ornithischia, Hadrosauridae) From The Kaiparowits Formation (Upper Cretaceous) Of Utah, Usa: Comparing Juvenile And Adult Morphology, Amanda "Billie" C. Guerrero

Electronic Theses, Projects, and Dissertations

This study documents the ontogenetic development of the braincase in Parasaurolophus, a lambeosaurine hadrosaurid dinosaur known for its distinctive cranial crest. Whereas the crest has been extensively examined for its roles in communication and display, the braincase remains less understood, despite its structural and functional relationship with the crest. This research compares the braincase morphology of a juvenile specimen (RAM 14000, "Baby Joe"), a subadult specimen (RAM 17000), and an adult P. tubicen (NMMNH P-25100), to investigate how developmental changes influenced sensory systems, neurocranial architecture, and biomechanical adaptations across ontogeny.

Detailed morphological analysis reveals progressive changes from juvenile to …

Characterization Of A New Domestic Feline Macrophage Cell Line To Study Molecular Mechanisms Of Feline Coronavirus, Adam Espinoza

Electronic Theses, Projects, and Dissertations

Feline Coronavirus (FCoV) is a veterinary pathogen common in domestic cats. FCoV is transmitted via the fecal-oral route, results in mild enteric symptoms, and is considered feline enteric coronavirus (FECV). During infection the virus may transition from infecting host enteric epithelial cells to infecting host macrophages, resulting in a lethal systemic disease, and the virus is now considered feline infectious peritonitis virus (FIPV). FIPV arises in an infected individual, is not shed in the feces, and is not transmitted from cat to cat. There is limited research defining the host molecular mechanisms driving FCoV lethal outcomes, with few feline cell …

Context Dependent Regulation Of Dicer Function During Oocyte-To-Embryo Transition, Nick A. Newkirk

Dissertations and Theses (Open Access)

Over two decades ago, Dicer was discovered as the primary enzyme responsible for the generation of small RNAs known as the microRNAs (miRNAs) and short interfering RNAs (siRNAs). Spatiotemporal regulation of Dicer-dependent small-RNA biogenesis affects many aspects of biology, including aging, disease progression, fertility, and cancer. Interestingly, a distinct population of Dicer-dependent small RNAs, known as the endogenous siRNAs (endo-siRNAs), are uniquely abundant in the germ cells and gametes, and are critical for normal fertility. Despite their function regulating new life, the mechanisms controlling their biogenesis and subsequent germ cell functions remain poorly defined. Work to parse these mechanisms in …

Effects Of Photo-Oxidized Crude Oil On Gulf Killifish Early Life Stages, Charles Campbell

LSU Master's Theses

Photo-oxidation of spilled crude oil generates polar compounds that can heighten toxicity to marine fish embryos. We investigated the effects of photo-oxidized crude oil on early life stages of Gulf killifish (Fundulus grandis) by exposing embryos under flow-through conditions to water-accommodated fractions of four oil treatments: fresh oil unexposed to either sunlight or weathering referred to as dark control (DC), a UV-light oxidized whole oil (LT), the polar fraction extracted from LT (Pol) and the remnants after extracting the Pol from LT (NP). Oil loadings of 0.38–3.00 g oil/kg water were tested. Total PAH concentrations and chemical profiles …

Investigating The Effects Of Cbd And Caffeine Interaction On Embryonic Development In Xenopus Laevis, Jeanesia M. Pierre

Theses

This study examined the interactive effects of cannabidiol (CBD) and caffeine on Xenopus laevis embryos over a 96-hour exposure period. Developmental toxicity was assessed using toxic unit isobole analysis, with LC₅₀, EC₅₀, and teratogenic index (TI) values calculated for CBD, caffeine, and mixtures at 3:1, 1:1, and 1:3 ratios.

Results showed that mixtures produced concentration-dependent interactions. When caffeine levels were higher, the mixtures displayed synergistic toxicity; as the proportion of CBD increased, the interaction shifted toward a concentration-addition model. Mortality was elevated in mixtures relative to single-compound exposures, while malformation rates decreased, indicating reduced teratogenicity. Overall, findings suggest that CBD …

Stayin' Alive (Even Without Oxygen): Retinal Development In Austrofundulus Limnaeus, Carmen Zecilia Rodriguez

Dissertations and Theses

The vertebrate eye is one of the most metabolically active organs in the body and is particularly sensitive to environmental stressors such as oxygen deprivation. Understanding how eye development proceeds under such conditions can provide critical insights into mechanisms of cellular resilience, tissue organization, and developmental plasticity. The annual killifish Austrofundulus limnaeus represents a unique model for investigating these processes due to its remarkable tolerance to anoxia during embryogenesis. However, the wild-type form is heavily pigmented, limiting the effectiveness of traditional imaging techniques for studying eye development. This thesis characterizes eye development and anoxia resilience in both wild-type and melanin-deficient …

Retinal Precursor Cell Enriched Multiomic And Pseudo-Time Analysis Of Developing And Reprogrammed Photoreceptors, Brendon M. Patierno

Dissertations, Theses, and Capstone Projects

The vertebrate retina is a complex tissue made up of seven major cell subtypes which during development must differentiate and localize into a highly organized structure. These neuronal cells do not regenerate if damaged or diseased, and the progressive deterioration of cone photoreceptor cells is the leading cause of age related blindness. Currently there are no cures for this disease, but one promising therapeutic avenue is cell transplantation research. If we can further elucidate the gene regulatory networks that define cone cell development, this knowledge could be applied to the generation of healthy cone cells in clinically relevant models.

The …

Protocol For Vibratome Sectioning, Immunofluorescence, And S-Phase Labeling Of Inner Ear Organoids, Jiayi Wu, Stefan Heller, Maggie S. Matern

Biology Faculty Publications

Inner ear organoids represent a potentially inexhaustible source of otic tissues, including sensory hair cells and supporting cells, for in vitro manipulation. Here, we present a protocol for labeling S-phase entry of cells in inner ear organoids using 5-ethynyl-2′-deoxyuridine (EdU), followed by fixation and vibratome sectioning. Nuclear EdU is then detected alongside protein markers of interest via immunofluorescence. This workflow enables the visualization of cell and tissue morphologies within developing organoids and assessment of how different manipulations affect cell proliferation.

Global Erk/Mapk Activation Determines Oncogenic Fitness In Kras-Mutant Pancreatic Ductal Adenocarcinoma, Rachel A. Burge

MUSC Theses and Dissertations

In pancreatic ductal adenocarcinoma (PDAC), ~95% of cases harbor an activating KRAS mutation. The most common KRAS mutations in PDAC are KRAS^G12D (42%), KRAS^G12V (31%), and KRAS^G12R (15%). Patients harboring KRAS^G12R mutations have increased overall survival compared to those with KRAS^G12D/V-mutations. While KRAS^G12D/Vare common in all KRAS-mutant cancers, KRAS^G12Ris only common in PDAC.

KRAS^G12R is unable to activate the lipid kinase PIK3CA, a KRAS effector that is important for tumorigenesis in murine models. To investigate the tumorigenic potential of KRAS^G12R and the mechanisms that enable this mutation …

Analysis Of An Ethanol Sensitive Bmp-Nkx2.3-Fgf Signaling Pathway In Pouch Morphogenesis., Hieu Dai Le Vo

Electronic Theses and Dissertations

Craniofacial malformations lie at the heart of Fetal Alcohol Spectrum Disorders (FASD). While there is growing evidence for a genetic component to FASD, little is known of the cellular mechanisms underlying these ethanol-sensitive loci in facial development. Bone Morphogenetic Protein (Bmp) signaling pathway dependent pouch formation is a key mechanism in facial development. We have previously shown that multiple Bmp mutants are sensitized to ethanol-induced facial defects. However, ethanol does not directly impact Bmp signaling. This suggests that downstream effectors, like nkx2.3 and Fibroblast Growth Factor (Fgf) signaling, may mediate the impact of ethanol on Bmp mutants. Here, I …

The Role Of Cleavage And Polyadenylation Spcific Factor 6 (Cpsf6) In Hematopoiesis, Fengxi Ye

Dissertations and Theses (Open Access)

Cleavage and polyadenylation specific factor 6 (Cpsf6) translocation is frequently reported in APLL, which is Acute Promyelocytic Leukemia (APL)-like acute myeloid leukemia (AML) and other types of blood diseases associated with abnormal hematopoiesis. CPSF6 is a subunit of the Cleavage Factor I mammalian (CFIm) complex, which regulates post-transcriptional alternative polyadenylation (APA) of pre-mRNAs. Previous research indicated that Cpsf6 plays an essential role in alternative polyadenylation, development, and tumorigenesis. However, the role of Cpsf6 in hematopoiesis is unknown. Given its roles in APA, development and cancer, we hypothesize that Cpsf6 plays a critical role in hematopoiesis and that its …

Metabolic And Physiological Regulation In C. Elegans: Insights Into Sperm Activation And Peroxisome-Mediated Longevity, Yash Flora

LSU Doctoral Dissertations

Organelle dynamics lie at the heart of cellular signaling and metabolic regulation, orchestrating physiological processes such as reproduction and aging across the lifespan. In this dissertation, I investigate how organelle-based signaling coordinates sperm activation and modulates organismal aging in the nematode Caenorhabditis elegans. I identify SPIN-4, a previously uncharacterized Spinster family transporter, as a key regulator of spermiogenesis. SPIN-4 is strongly expressed in developing sperm, localizes to the plasma membrane, and promotes sperm activation by facilitating the export of sphingosine-1-phosphate (S1P). Loss of spin-4 results in defective pseudopod formation, reduced motility, and compromised fertility, phenotypes that can be rescued …

Breaking The Rules: Post-Translational Modifications And Proteome Dynamics During Anoxia, Chelsea Jordan Hughes

Dissertations and Theses

Most organisms are ill-equipped to survive anoxia, but some organisms have developed molecular strategies to mitigate the cellular stressors associated with a lack of oxygen. While it is established that anoxic survival is contingent on metabolic suppression, it is unclear what mechanisms support this change in gene expression. Gene expression is regulated by a variety of mechanisms within the cell, including alteration of chromatin structure through histone modifications and protein modifications which contribute to the ever-changing proteomic landscape of the cell. Protein modifications such as ubiquitylation can lead to the degradation of proteins, while modifications to transcription factors can change …

Mechanisms Of Placental Impairment And The Upregulation Of Fetuin-B During Maternal Undernourishment, Mia Camilliere

NYMC Student Theses and Dissertations

Proper nutrition is crucial during pregnancy to support fetal and placental development. Failure to meet these nutritional needs can result in adverse health outcomes for both mother and baby. Despite its high prevalence in underdeveloped countries, maternal undernourishment is a public health issue worldwide. There are several possible causes of maternal undernourishment, and these can occur alone or in combination, such as poor access to nutrition, hyperemesis gravidarum, and drug use. This condition can adversely affect placental development and function to the extent of placental insufficiency, perturbing the entire pregnancy. The placenta is responsible not only for hormonally and physically …

Network Analysis Of Antimicrobial Resistance In Staphylococcus Aureus: Characterization Of Hub Genes And Their Functional Implications, Md Imran Hasan, Davida Smyth, Jeong Yang, Ashley Teufel

Masters Theses (Archived)

Antimicrobial resistance is a major cause of morbidity and mortality in patients with S. aureus infections. In this study, we analyzed genes, molecular mechanisms, and pathways driving drug resistance in S. aureus using network analysis. Using whole-genome sequencing (WGS) data and systems biology approaches, we identified 229 AMR-associated genes and constructed a protein-protein interaction network among these genes. Through network topology and functional enrichment analyses, we not only confirmed their association with resistance, but also highlighted the central roles of these genes in resistance pathways, such as efflux, target replacement, and target protection, which are directly linked to multiple drug …

Early Hematopoietic Differentiation Of An Inducible Pluripotent Stem Cell Model Of Infant Lymphoblastic Leukemia, Meagan Vacek, Jacqelyn Nemechek, Irina Pushel, Bradley Thornton, Priyanka Kumar, Jay L. Vivian, John M. Perry

Research Days

This abstract describes our work regarding the differentiation of human inducible pluripotent stem cells into hematopoietic stem and progenitor cells as the groundwork for the development of a genomics driven inducible pluripotent stem cell model of KMT2A rearranged infant acute lymphoblastic leukemia.

Neurodevelopmental And Environmental Mechanisms Of Invasion, Proliferation, And Tumor Cell Fate Specification In Glioblastoma, Bianca Lynn Myers

Biomedical Sciences ETDs

Glioblastomas (GBMs) are the most aggressive primary brain tumors, and despite over 50 years of research efforts, the median survival remains at 14 months post-diagnosis. The current standard of care consists of maximal surgical resection radiotherapy with concurrent chemotherapy using temozolomide. However, the highly proliferative and invasive nature of GBM cells renders total resection nearly impossible as tumor cells invade the surrounding healthy tissue. The molecular and environmental drivers of these tumorigenic phenotypes are largely unknown. Here, we demonstrate that the neurodevelopmental transcription factor ASCL1 enhances tumor cell proliferation and invasion while activating the expression of a neural stem cell …

Mesoderm-Specific Transcript Has A Role In The Systemic Regulation Of Obesity, Maria J. Orellana Rosales

Thinking Matters Symposium

Mesoderm specific transcript (Mest) expression in white adipose tissue (WAT) is variable in genetically identical mice. Previous studies have shown a connection between Mest high expression and propensity for fat mass expansion. WAT and liver crosstalk has been well documented with hormone-like peptides signaling and regulating important metabolic pathways. The aim of this study is to investigate the correlation between these circulating factors and Mest expression in mice after exposure to a high fat diet (HFD). A group of 120 C57B6/J mice, males and females, were exposed to a HFD (Western Diet, 40 kcal% fat) for 4 weeks (8-12 weeks …

The Role Of Elongin B In Drosophila Melanogaster Muscle Development, Madelyne Dayan

Student Theses and Dissertations

Muscle atrophy is a result of a number of muscle diseases, as well as aging, disuse, and infections. Muscles weakened in these ways exhibit a characteristic decrease in size, strength, and mobility. The similarities between muscle in humans and Drosophila allow for direct comparisons to be made in vertebrates from studying muscle in Drosophila. Differential gene expression has been shown to play an important role in embryonic muscle development in Drosophila melanogaster. A previous study identified Elongin B (EloB) to be involved in somatic muscle morphogenesis in Drosophila, with mutant embryos displaying severe muscle defects, including thin, mis-attached, and missing …