Developmental Biology Commons^™

Modeling Inherited Retinal Disease In Zebrafish, Meet Patel

Theses and Dissertations--Biology

Inherited retinal diseases (IRDs) affect millions of people worldwide. Majority of IRDs are caused by degeneration of rod and cone photoreceptor cells (PRCs) due to gene mutations. The overarching goal of my dissertation is to model and evaluate the molecular role of various gene candidates involved in IRDs such as cone rod dystrophy (CRD) and retinitis pigmentosa (RP).

Mutations in CDHR1, a photoreceptor specific cadherin have been associated with CRD and recapitulated in mouse CDHR1 knockouts. However, the molecular function of CDHR1 remains unknown. CDHR1 has been shown to localize at the leading edge of murine rod nascent outer segment …

The Impact Of Maternal Environmental Exposures On The Immune Landscape Of The Maternal-Fetal Interface, Heather E. True

Theses and Dissertations--Pharmacy

Maternal environmental exposures and inflammation are known to impact fetal development in utero as well as increase the risk for chronic diseases later in life. Therefore, it is essential that we understand how the maternal environment alters placental structure and immune function.

Therefore, we isolated fetal (chorionic villous) tissues from the placentas of healthy pregnant participants (control) and those with inflammatory conditions, including SARS-COV-2 infection, pregravid obesity, and opioid use disorder. Isolated placental leukocytes were subjected to a series of assays to uncover the phenotypic, functional, and transcriptional (single-cell RNA-sequencing) landscape of placental immune cells. Additional placental tissues were subjected …

Exploring The Links Among Brain Iron Accumulation, Cognitive Performance, And Dietary Intake In Older Adults: A Longitudinal Mri Study, Valentinos Zachariou, Colleen A. Pappas, Christopher E. Bauer, Elayna R. Seago, Brian T. Gold

Neurology Faculty Publications

This study evaluated longitudinal brain iron accumulation in older adults, its association with cognition, and the role of specific nutrients in mitigating iron accumulation. MRI-based, quantitative susceptibility mapping estimates of brain iron concentration were acquired from seventy-two healthy older adults (47 women, ages 60–86) at a baseline timepoint (TP1) and a follow-up timepoint (TP2) 2.5–3.0 years later. Dietary intake was evaluated at baseline using a validated questionnaire. Cognitive performance was assessed at TP2 using the uniform data set (Version 3) neuropsychological tests of episodic memory (MEM) and executive function (EF). Voxel-wise, linear mixed-effects models, adjusted for longitudinal gray matter volume …

Temporal Dynamics Of Programmed Genome Rearrangement In Sea Lamprey Embryogenesis: A Deep Learning & Lightsheet Imaging Approach To Studying Early Developmental Transitions, Kasturi Rajandran

Theses and Dissertations--Biology

Programmed genome rearrangement (PGR) in the sea lamprey (Petromyzon marinus) leads to the elimination of ~0.5Gb (20%) of the germline genome during early embryogenesis, yet its timing relative to the maternal-to-zygotic transition (MZT) remains unclear. In this study, we imaged embryos cleared at 3-hour intervals (up to 72 hours post fertilization (hpf)) using high-resolution lightsheet fluorescence microscopy and a custom deep-learning image-analysis pipeline (~80% accuracy) to quantify nuclei and micronuclei counts. Micronuclei, which are the hallmarks of PGR first appear between 24 to 27hpf (vs ~36hpf previously reported) indicating PGR starts earlier than previously reported in the sea …

Pharmacological Or Genetic Inhibition Of Ltcc Promotes Cardiomyocyte Proliferation Through Inhibition Of Calcineurin Activity, Lynn A. C. Devilée, Abou Bakr M. Salama, Jessica M. Miller, Janice D. Reid, Qinghui Ou, Nourhan M. Baraka, Kamal Abou Farraj, Madiha Jamal, Yibing Nong, Todd K. Rosengart, Douglas A. Andres, Jonathan Satin, Tamer M. A. Mohamed, James E. Hudson, Riham R. E. Abouleisa

Markey Cancer Center Faculty Publications

Cardiomyocytes (CMs) lost during ischemic cardiac injury cannot be replaced due to their limited proliferative capacity. Calcium is an important signal transducer that regulates key cellular processes, but its role in regulating CM proliferation is incompletely understood. Here we show a robust pathway for new calcium signaling-based cardiac regenerative strategies. A drug screen targeting proteins involved in CM calcium cycling in human embryonic stem cell-derived cardiac organoids (hCOs) revealed that only the inhibition of L-Type Calcium Channel (LTCC) induced the CM cell cycle. Furthermore, overexpression of Ras-related associated with Diabetes (RRAD), an endogenous inhibitor of LTCC, induced CM cell cycle …

Soxb1 Transcription Factors Are Essential For Initiating And Maintaining Neural Plate Border Gene Expression, Elizabeth Schock, Joshua R. York, Austin P. Li, Ashlyn Y. Tu, Carole Labonne

Markey Cancer Center Faculty Publications

SoxB1 transcription factors (Sox2/3) are well known for their role in early neural fate specification in the embryo, but little is known about functional roles for SoxB1 factors in non-neural ectodermal cell types, such as the neural plate border (NPB). Using Xenopus laevis, we set out to determine whether SoxB1 transcription factors have a regulatory function in NPB formation. Here, we show that SoxB1 factors are necessary for NPB formation, and that prolonged SoxB1 factor activity blocks the transition from a NPB to a neural crest state. Using ChIP-seq, we demonstrate that Sox3 is enriched upstream of NPB genes in …

Functional Analyses Of The Polycomb-Group Genes In Sea Lamprey Embryos Undergoing Programmed Dna Loss, Cody Saraceno

Theses and Dissertations--Biology

During early embryonic development, the sea lamprey (Petromyzon marinus) undergoes programmatic elimination of DNA from somatic progenitor cells in a process termed programmed genome rearrangement (PGR). Eliminated DNA eventually becomes condensed into micronuclei, which are then physically degraded and permanently lost from the cell. Previous studies indicated that many of the genes eliminated during PGR have mammalian homologs that are bound by polycomb repressive complex (PRC) in embryonic stem cells. To test whether PRC components play a role in the faithful elimination of germline-specific sequences, we used a combination of CRISPR/Cas9 and lightsheet microscopy to investigate the impact …

Pai-1 As A Critical Factor In The Resolution Of Sepsis And Acute Kidney Injury In Old Age, Maria E. C. Bruno, Sujata Mukherjee, Jamie L. Sturgill, Virgilius Cornea, Peng Yeh, Gregory S. Hawk, Hiroshi Saito, Marlene E. Starr

Markey Cancer Center Faculty Publications

Elevated plasma levels of plasminogen activator inhibitor type 1 (PAI-1) are documented in patients with sepsis and levels positively correlate with disease severity and mortality. Our prior work demonstrated that PAI-1 in plasma is positively associated with acute kidney injury (AKI) in septic patients and mice. The objective of this study was to determine if PAI-1 is causally related to AKI and worse sepsis outcomes using a clinically-relevant and age-appropriate murine model of sepsis. Sepsis was induced by cecal slurry (CS)-injection to wild-type (WT, C57BL/6) and PAI-1 knockout (KO) mice at young (5–9 months) and old (18–22 months) age. Survival …

Production And Characterization Of Monoclonal Antibodies To Xenopus Proteins, Brett Horr, Ryan Kurtz, Ankit Pandey, Benjamin G. Hoffstrom, Elizabeth Schock, Carole Labonne, Dominique Alfandari

Markey Cancer Center Faculty Publications

Monoclonal antibodies are powerful and versatile tools that enable the study of proteins in diverse contexts. They are often utilized to assist with identification of subcellular localization and characterization of the function of target proteins of interest. However, because there can be considerable sequence diversity between orthologous proteins in Xenopus and mammals, antibodies produced against mouse or human proteins often do not recognize Xenopus counterparts. To address this issue, we refined existing mouse monoclonal antibody production protocols to generate antibodies against Xenopus proteins of interest. Here, we describe several approaches for the generation of useful mouse anti-Xenopus antibodies to multiple …

Epigenetic Regulation Of Insect Development, Yaoyu Jiao

Theses and Dissertations--Entomology

Insects undergo a series of distinct life stages such as egg, larva and pupa to develop into mature adults capable of reproduction throughout their life cycle. In the larval stage, insects experience the fastest growth with voracious feeding and multiple cuticle shedding resulting in hundreds-of-fold increasing of size. During metamorphosis, insects stop increasing body size but go through dramatic tissue transformation, developing wings and other adult features. The characteristic mode of insect development, especially the metamorphosis, makes insects the most successful group of animals on the earth. However, the epigenetic mechanisms behind insect development remain elusive. Studying the epigenetic regulation …

Exploring The Molecular Basis Of Touch: A Comparative Analysis Of Gene Expression In Sensory Corpuscle-Rich And Corpuscle-Poor Skin Regions In The Duck, Thomas Hart

Theses and Dissertations--Biology

Cutaneous touch is facilitated by discrete cellular complexes composed of non-neuronal cells associated with mechanoreceptor neuron endings. The non-neuronal cells of these cutaneous end organ complexes (CEOCs) are believed to contribute to touch, but their role in touch sensation remains unclear. To better understand the function of CEOC cells, we sought to characterize the transcriptional profile of CEOC-rich tissue and identify genes expressed in CEOC cells. Bill skin of the tactile foraging Pekin duck (Anas platyrhynchos) is dense with CEOCs, specifically the avian analogs of mammalian Pacinian and Meissner corpuscles, while corpuscles in duck foot skin are scarce. Using RNA …

Dysregulated Polycomb Repressive Complex 2 Contributes To Chronic Obstructive Pulmonary Disease By Rewiring Stem Cell Fate, Aria Byrd, Xufeng Qu, Alexsandr Lukyanchuk, Jinpeng Liu, Fan Chen, Kassandra J. Naughton, Tanner Ducote, Xiulong Song, Hannah Bowman, Yanming Zhao, Abigail R Edgin, Chi Wang, Jinze Liu, Christine Fillmore Brainson

Markey Cancer Center Faculty Publications

Aberrant lung cell differentiation is a hallmark of many lung diseases including chronic obstructive pulmonary disease (COPD). The EZH2-containing Polycomb Repressive Complex 2 (PRC2) regulates embryonic lung stem cell fate, but its role in adult lung is obscure. Histological analysis of patient tissues revealed that loss of PRC2 activity was correlated with aberrant bronchiolar cell differentiation in COPD lung. Histological and single-cell RNA-sequencing analyses showed that loss of EZH2 in mouse lung organoids led to lowered self- renewal capability, increased squamous morphological development, and marked shifts in progenitor cell populations. Evaluation of in vivo models revealed that heterozygosity of Ezh2 …

Investigating The Role Of Chd7 And Sox11 In Retinal Cell Development And The Ocular Complications Of Charge Syndrome, Laura Krueger

Theses and Dissertations--Biology

Proper formation of the visual system requires the precise interaction of several embryonic cell lineages, including the neuroectoderm (forms the retina and retinal pigment epithelium), surface ectoderm (forms the lens), mesoderm and cranial neural crest cells (form the ocular blood vessels and anterior ocular structures). When this process is disrupted structural birth defects such as coloboma result, leading to pediatric visual deficits. Ocular developmental defects are often present in larger syndromic disorders. One example is CHARGE syndrome, a genetic disorder characterized by coloboma, heart defects, choanal atresia, growth retardation, genital abnormalities, and ear abnormalities. Pathogenic variants in CHD7 have been …

The Role Of Sox4 In Ocular Morphogenesis And Retinal Differentiation, Rebecca Petersen

Theses and Dissertations--Biology

Visual impairment ranges from mild forms that can be corrected with glasses to more severe cases that result in permanent loss of vision. Microphthalmia, anophthalmia, and coloboma (collectively referred to as MAC) account for 11% of cases of pediatric blindness and are a result of improper ocular morphogenesis. Retinitis Pigmentosa (RP) is a retinal degenerative disease that affects 1 in 3000 people worldwide. It is a progressive disorder that initially begins with loss of vision in low light settings due to rod photoreceptor degeneration but progresses to complete blindness upon loss of cone photoreceptors. Currently, there is no cure for …

The Role Of Shoc2 In Embryonic Development, Rebecca G. Norcross

Theses and Dissertations--Molecular and Cellular Biochemistry

The canonical ERK1/2 signaling cascade regulates cellular functions critical in vertebrate embryonic development such as proliferation, apoptosis, differentiation, and migration. Thus, its signals are controlled by a variety of mechanisms. Scaffold proteins are considered central to the mechanisms regulating the transmission of the ERK1/2 signals. Yet, their functions in development nor the molecular mechanisms by which they exert their control are not well understood.

This study focuses on the essential regulator of ERK1/2 signals during development – the scaffold protein Shoc2. Loss of Shoc2 leads to early embryonic lethality in mice and zebrafish. Germline mutations in the shoc2 gene result …

Understanding The Effects Of Embryonic Hyperglycemia On Retinal Development And Maintenance, Kayla Titialii-Torres

Theses and Dissertations--Biology

Hundreds of millions of people are affected by diabetes worldwide. Whether they are diagnosed with prediabetes or Type I or II diabetes, there are a variety of mechanisms in the pathogenesis of diabetes. Diabetes is a disease which consists of recurring states of hyperglycemia that can be difficult to manage due to either lack of insulin production or improper utilization of insulin. While these mechanisms of action differ, complications induced by diabetes occur in both poorly regulated Type I and II. Common complications of diabetes include nerve damage, kidney damage, and eye damage. Eye damage specifically is called diabetic retinopathy …

Identifying Epidermal Enriched Genes Required For Planarian Regeneration- Sp. Schmidtea Mediterranea, Pallob Barai

Theses and Dissertations--Biology

The outer epithelial layer covering an organism, commonly known as the epidermis, is crucial for maintaining homeostasis and for the wound healing processes after injury. The planarian epidermis allows flatworms to heal their wounds and virtually restore any missing tissues. Immediately after amputation, planarians contract their muscle and stretch their epidermis to heal the wound area. However, how the planarian epidermis coordinates with other tissues and mechanisms after the initial wound healing processes begins is not understood in detail. I hypothesized that epidermal cell stretching upon wound healing induces transcriptional changes that are required for effective regeneration. To test this …

Understanding The Cellular And Physiological Mechanisms Of Fertilization And Early-Stage Seed Development, Mohammad Foteh Ali

Theses and Dissertations--Plant and Soil Sciences

Flowering plants have evolved a unique double-fertilization process. Two sperm cells fuse with two female gametophytic cells, the egg and central cells within the ovule, giving rise to the embryo and endosperm, respectively. Sperm cells in flowering plants are nonmotile and delivered in close proximity to the egg and central cells by the pollen tube. Flowering plants have established filamentous actin (F-actin) based sperm nuclear migration system for successful fertilization. Prior to fertilization, the female gamete forms a mesh-like structure of F-actin that shows constant inward movement from the plasma membrane periphery to the center of the cell where the …

Insights Into The Molecular Evolution Of Fertilization Mechanism In Land Plants, Vijyesh Sharma, Anthony J. Clark, Tomokazu Kawashima

Plant and Soil Sciences Faculty Publications

Land plants have evolved successive changes during their conquest of the land and innovations in sexual reproduction have played a major role in their terrestrialization. Recent years have seen many revealing dissections of the molecular mechanisms of sexual reproduction and much new genomics data from the land plant lineage, including early diverging land plants, as well as algae. This new knowledge is being integrated to further understand how sexual reproduction in land plants evolved, identifying highly conserved factors and pathways, but also molecular changes that underpinned the emergence of new modes of sexual reproduction. Here, we review recent advances in …

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 …

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, …

Cellular Dynamics Of Double Fertilization And Early Embryogenesis In Flowering Plants, Ji Min Shin, Ling Yuan, Masaru Ohme-Takagi, Tomokazu Kawashima

Plant and Soil Sciences Faculty Publications

Flowering plants (angiosperms) perform a unique double fertilization in which two sperm cells fuse with two female gamete cells in the embryo sac to develop a seed. Furthermore, during land plant evolution, the mode of sexual reproduction has been modified dramatically from motile sperm in the early-diverging land plants, such as mosses and ferns as well as some gymnosperms (Ginkgo and cycads) to nonmotile sperm that are delivered to female gametes by the pollen tube in flowering plants. Recent studies have revealed the cellular dynamics and molecular mechanisms for the complex series of double fertilization processes and elucidated differences …

Limb Development In Salamanders: An Evolutionary Perspective To The Tetrapod Limb, Sruthi Purushothaman

Theses and Dissertations--Biology

Vertebrate limb is an ideal model to study growth, patterning and morphogenesis and the interplay between these processes. The developing limb bud is a three-dimensional structure and its outgrowth depends on the interaction between 2 important signaling centers: the Apical Ectodermal Ridge (AER) at the junction of the dorsal and ventral halves of the limb bud and the Zone of Polarizing activity (ZPA) in the posterior mesenchyme. These centers produce their respective key molecules and the close interplay between them specifies structures along the anterior-posterior (thumb to pinky), proximal-distal (shoulder to fingertips) and dorsal-ventral (knuckle to palm) axes.

Developmental biologists …

Siah-Mediated Ups Regulation Of The Development Of The Visual System In Zebrafish (Danio Rerio), Warlen Pereira Piedade

Theses and Dissertations--Biology

The eye is a complex organ responsible for vision that which formation depends on several intricate developmental steps. Vision for humans is responsible for the majority of its sensory interactions with the environment. Eye development can be divided into two critical stages: morphogenesis, which establishes the eye structure culminating with the fusion of the optic fissure, a transient cleft important for eye vascularization, and subsequently specification and differentiation of the retina to form every type of retinal neuronal cell, including photoreceptors, rods and cones. Developmental failure in either of these critical stages can lead to inherited congenital or age-related blinding …

The Roles Of Polar Cell Extensions In Drosophila Micropyle Formation, Bradford Hull

Theses and Dissertations--Biology

The Drosophila micropyle is a conserved formation utilized to allow sperm passage past the robust eggshell structure for fertilization. Micropyle formation follows a unique acellular tubulogenesis method where it is secreted and shaped by specialized follicle cells including the border cells and polar cells. In late oogenesis, the polar cells form extensions that are necessary to create the micropyle pore through which sperm enters. Previous work established that polar cell extension presence is required for micropyle pore formation. We investigated temporal requirements of extensions throughout chorion deposition and found extensions are required during the beginning and middle of choriogenesis, but …

Connective Tissue Fibroblasts From Highly Regenerative Mammals Are Refractory To Ros-Induced Cellular Senescence, Sandeep Saxena, Hemendra J. Vekaria, Patrick G. Sullivan, Ashley W. Seifert

Biology Faculty Publications

A surveillance system in mammals constantly monitors cell activity to protect against aberrant proliferation in response to damage, injury and oncogenic stress. Here we isolate and culture connective tissue fibroblasts from highly regenerative mammals (Acomys and Oryctolagus) to determine how these cells interpret signals that normally induce cellular senescence in non-regenerating mammals (Mus and Rattus). While H₂O₂ exposure substantially decreases cell proliferation and increases p53, p21, p16, and p19 in cells from mice and rats, cells from spiny mice and rabbits are highly resistant to H₂O₂. Quantifying oxygen consumption …

Fgf-Signaling Is Compartmentalized Within The Mesenchyme And Controls Proliferation During Salamander Limb Development, Sruthi Purushothaman, Ahmed Elewa, Ashley W. Seifert

Biology Faculty Publications

Although decades of studies have produced a generalized model for tetrapod limb development, urodeles deviate from anurans and amniotes in at least two key respects: their limbs exhibit preaxial skeletal differentiation and do not develop an apical ectodermal ridge (AER). Here, we investigated how Sonic hedgehog (Shh) and Fibroblast growth factor (Fgf) signaling regulate limb development in the axolotl. We found that Shh-expressing cells contributed to the most posterior digit, and that inhibiting Shh-signaling inhibited Fgf8 expression, anteroposterior patterning, and distal cell proliferation. In addition to lack of a morphological AER, we found that salamander …

Tgf-Β, Wnt, And Fgf Signaling Pathways During Axolotl Tail Regeneration And Forelimb Bud Development, Qingchao Qiu

Theses and Dissertations--Neuroscience

Tgf-β, Wnt, and Fgf signaling pathways are required for many developmental processes. Here, I investigated the requirement of these signaling pathways during tail regeneration and limb development in the Mexican axolotl (Ambystoma mexicanum).

Using small chemical inhibitors during tail regeneration, I found that the Tgf-β signaling pathway was required from 0-24 and 48-72 hours post tail amputation (hpa), the Wnt signaling pathway was required from 0-120 hpa, and the Fgf signaling pathway was required from 0-12hpa. Tgf-β1 was upregulated after amputation and thus may mediate Tgf-β signaling pathway during tail regeneration. Both Smad-mediated and non-Smad mediated Tgf-β signaling …

Functional Analysis Of Protease Adamts 6 During Vertebrate Eye Formation, Austin Taylor

Lewis Honors College Capstone Collection

Extracellular matrix (ECM) remodeling and epithelial sheet fusion occur during the development of many different tissues, including the vertebrate eye (Lu et al., 2011) (Pai et al., 2012). During morphogenesis of the eye, the ventral hemisphere of the developing retinal tissue forms an opening called the optic fissure which must undergo epithelial fusion (Pai et al., 2012). Failure of optic fissure fusion leads to a congenital blinding disorder called coloboma (Gregory-Evans, 2004). A long standing question pertaining to the mechanism of optic fissure fusion is exactly which ECM remodeling enzymes are actively involved in dismantling the ECM to allow for …