Developmental Biology Commons^™

Genetic Regulation Of Uterine Organogenesis, Diana A. Machado

Dissertations and Theses (Open Access)

In eutherian and marsupial mammals, the site of embryo implantation and gestation is the uterus. The precursor tissue of the uterus, oviducts, cervix, and upper vagina is the Müllerian duct epithelium and its adjacent mesenchyme. Morphological uterine variation between species is established during embryogenesis by species-specific differences in Müllerian duct fusion at the midline, growth, and differentiation. For example, laboratory mice have a bipartite uterus with two uterine horns and a single cervix, whereas humans have a simplex uterus with a single chamber and single cervix. In humans, variations in the fusion process can alter typical uterine morphology, correlating with …

Transcriptional Regulation In The Uterine Luminal Epithelium, Evelyn A. Carrion

Dissertations and Theses (Open Access)

Transcriptional Regulation in the Uterine Luminal Epithelium

Evelyn A. Carrion

Advisor: Richard R. Behringer, PhD

Abstract

The uterus is an organ comprised of multiple tissues that are essential for women’s health and reproduction. The uterus is composed of multiple tissue layers, including the perimetrium, myometrium, and the endometrium. The endometrium is the inner lining of the uterus, and contains the luminal epithelium, glandular epithelium, and stroma. The luminal epithelium is a simple columnar layer of cells that is necessary for embryo implantation. The uterus is derived in part from the embryonic precursor tissue called the Müllerian duct. There are no …

Regulation Of Müllerian Duct Mesenchyme Transcription During Mammalian Sex Differentiation, Haowen Li, Richard R Behringer, Rachel D Mullen

Dissertations and Theses (Open Access)

Sp7/Osterix (Osx) encodes a zinc-finger transcription factor of the Specificity-protein family discovered by Nakashima et al. at the MD Anderson Cancer Center. While primarily recognized for its role in osteogenesis, Osx has also been implicated in mammalian reproductive development, particularly in male sex differentiation, where Müllerian Duct (MD) regression occurs, mediated by anti-Müllerian hormone (AMH) signaling. AMH-induced regression signals are transduced by the mesenchymal tissue surrounding the ductal structure, known as the Müllerian Duct mesenchyme (MDM). It was discovered that AMH signaling is necessary and sufficient for driving Osx expression in MDM. A previous transgenic mouse reporter …

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 …

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 …

Uncovering A Fundamental Mechanism Underlying Female Oocyte Quality And Rasopathies Using C. Elegans As A Model System, Han Bit Baek

Dissertations and Theses (Open Access)

Signaling pathways are molecular networks that allow cells to communicate between and within themselves. They are crucial for the coordination of diverse cellular processes and are the molecular mechanism in which cells sense and respond to their environment. RAS (Rat Sarcoma) is a small GTPase that transmits extracellular growth factor signals through a downstream kinase cascade and ERK (Extracellular-signal regulated kinase) is the terminal kinase, and it controls cellular processes such as proliferation, differentiation, and survival by phosphorylating its downstream effectors. This post translational modification regulates the effector by modulating its activity, levels, and/or interaction with other molecules. Given the …

The Role Of Wt1 In Müllerian Duct Development, Jace Aloway

Dissertations and Theses (Open Access)

WT1 is a zinc finger transcription factor widely expressed in the urogenital system. Human mutations of WT1 lead to pediatric nephroblastoma as well as frequent differences of sex development (DSDs). Previous studies have suggested that WT1 acts as an activator for Amhr2, a necessary component of typical male differentiation. We used the mouse as a model to investigate the role of WT1 in sex development, where we deleted Wt1 in the Müllerian duct (MD) mesenchyme using a novel conditional null reporter allele, Wt1 flox-RFP. This allele utilizes the Cre-lox system to delete exons 8 and 9 of Wt1 …

The Role Of The Transcription Factor Cebpa In Regulating Lung Alveolar Type 2 Cell Fate In Vivo, Dalia Hassan

Dissertations and Theses (Open Access)

Cell plasticity can extend across all possible cell types, yet it naturally diminishes as cells progress through differentiation. This plasticity can be reactivated during injury repair, engaging developmental flexibility. Our investigations reveal the critical role of the transcription factor (TF) CEBPA, specific to lung alveolar type 2 (AT2) cells, in modulating AT2 cell plasticity within the mouse lung. We demonstrate that CEBPA constrains AT2 cell plasticity by promoting the AT2 differentiation program and recruiting the lineage-specific TF NKX2-1. Without CEBPA, AT2 cells, in both neonatal and mature, show a diminished AT2 program; however, only neonatal cells re-activate the SOX9 progenitor …

Functional Analysis Of Daxx In Tumorigenesis Of Pancreatic Neuroendocrine Tumors And Embryonic Development, Chang Sun

Dissertations and Theses (Open Access)

Death domain-associated protein 6 (Daxx) is a histone chaperone specific to Histone 3.3 (H3.3). DAXX interacts with ATRX forming a chromatin remodeling complex, which deposits H3.3 into telomeric and pericentric region of the genome. The importance of Daxx was manifested in embryonic development. The loss of Daxx leads to early lethality in mouse embryos around E6.5. Moreover, sequencing studies have revealed the importance of DAXX in human tumors. Mutually exclusive mutations in DAXX and ATRX occur in about 30% of pancreatic neuroendocrine tumors (PanNETs). Although lots of progress has been made in studying functions of DAXX, we still do not …

Adipocytes And Innate Immunity In Systemic Sclerosis, Nancy Wareing

Dissertations and Theses (Open Access)

Systemic sclerosis (SSc; scleroderma) is a chronic systemic autoimmune and connective tissue disorder characterized by vasculopathy, autoimmune phenomena, and widespread fibrosis. Skin thickening and tightening is the cardinal feature of SSc and is responsible, in part, for the considerable morbidity of this disease. There are currently no targeted treatments for skin manifestations in SSc, primarily due to our fragmented understanding of its pathophysiologic mechanisms. In PART I, we report a previously unappreciated link between aberrant expression of the developmental gene sine oculis homeobox homolog 1 (SIX1) in skin-associated adipocytes in SSc skin and the early loss of dermal white adipose …

Genetic Regulation Of Müllerian Duct Regression, Malcolm Moses

Dissertations and Theses (Open Access)

Mammals, including humans, develop progenitor tissues for both male and female reproductive tract organs before they fully differentiate into a male or female tract. The progenitor tissue for the male reproductive tract is known as the Wolffian duct (WD), and the progenitor tissue for the female reproductive tract is the Müllerian duct (MD). The WD further differentiates into the vas deferens, epididymis, and seminal vesicle, while the MD differentiates into the oviduct, uterus and upper vagina. An essential step in sex differentiation for males is the regression of the MD. This regression initiates with anti-Müllerian hormone (Amh) transcription …

The Adar-Mavs Pathway Is A Critical Mediator Of The Innate Immune System In Pancreatic Development And Cancer, Dhwani Rupani

Dissertations and Theses (Open Access)

Adenosine deaminase acting on RNA (ADAR) is an RNA-binding protein that deaminates adenosine (A) to inosine (I). A-to-I editing is an important post-transcriptional mechanism to prevent recognition of endogenous RNA by MDA5, a cytosolic RNA sensor. Activation of MDA5 by viral RNA can stimulate the innate immune system. Thus, ADAR-mediated RNA editing is crucial to distinguish “self” from “non-self”. ADAR has an important role in gene regulation as A-to-I editing alters RNA processing affecting both RNA and protein abundance. Given its importance in regulating innate immunity and transcript abundance, aberrations in Adar expression are implicated in developmental deformities and carcinogenesis. …

The Novel Role Of Dnmbp In Kidney Development, Brandy Walker

Dissertations and Theses (Open Access)

Congenital anomalies of the kidney and urinary tract (CAKUT) accounts for nearly one-fourth of all birth defects and more than 40% of pediatric end-stage renal disease, yet only 10-20% of CAKUT cases have a known monogenetic cause. Human kidneys are composed of up to a million epithelial tubules called nephrons. Disruption of nephron development is one of the many congenital anomalies that cause CAKUT, often resulting in chronic or end-stage renal disease which requires transplant. During nephron epithelialization, the formation of stable cadherin-mediated adhesion junctions is essential for maintaining cell-cell contacts. To understand the cell behaviors underlying abnormalities in renal …

Regulation Of Lung Mesenchymal Cells By Epithelial Wnt Ligands, Odemaris Narvaez Del Pilar

Dissertations and Theses (Open Access)

The mesenchyme comprises of heterogeneous cell populations that support neighboring structures and are integral to intercellular signaling. Despite such importance, mesenchymal cells are poorly defined morphologically and molecularly. Their signaling regulation is not well understood, lagging their counterparts in the epithelial, endothelial, and immune lineages. Leveraging single-cell RNA-seq, three-dimensional imaging, and lineage tracing, first, we delineated different lung mesenchymal cell types and classified them into three-proximal-distal axes in the neonatal and adult murine lung. Each axis is associated to the structure they support – the endothelium, epithelium and interstitium. We also identified two subpopulations of neonatal lung myofibroblasts – ductal …

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 …

The Genome-Wide Roles Of The Lung Lineage Transcription Factor Nkx2-1 In The Regulation Of Opposing Cell Fates In Vivo, Danielle Renae Little

Dissertations and Theses (Open Access)

Lineage transcription factors mark, promote, and maintain multiple distinct cell types originating from a common progenitor. Despite their essential role, how such factors function and bind genome wide to orchestrate the epigenetic changes necessary to form and maintain these identities in vivo is unclear. One lineage transcription factor NK Homeobox 2-1 (NKX2-1) is expressed throughout the lung epithelium during development and was thought to be lost in the extraordinarily thin cell type required for gas exchange– the alveolar type 1 (AT1) cell. Complementing precise genetic knockouts with cell type-specific ChIP-seq, ATAC-seq, and scRNA-seq, our study shows that AT1 and AT2 …

The Role Of Daam1 In Kidney Development, Vanja Krneta-Stankic

Dissertations and Theses (Open Access)

Kidneys, like most organs in our bodies, consist of a network of epithelial tubules. Kidney tubules are called nephrons, and their morphology is important for kidney function. Nephrons develop from mesodermally derived aggregates of progenitor cells. The nephric progenitors organize into nephric tubules lined with hair-like sensory projections called cilia. Many diseases of the kidney are characterized by abnormal nephron morphology with current treatment aimed at symptom control. To understand the mechanisms underlying kidney diseases and achieve the development of novel therapies, a better understanding of how nephrons develop is needed. Although the actin cytoskeleton is critical for cell behaviors …

The Role Of Daam1 In Kidney Development, Vanja Krneta-Stankic

Dissertations and Theses (Open Access)

Kidneys, like most organs in our bodies, consist of a network of epithelial tubules. Kidney tubules are called nephrons, and their morphology is important for kidney function. Nephrons develop from mesodermally derived aggregates of progenitor cells. The nephric progenitors organize into nephric tubules lined with hair-like sensory projections called cilia. Many diseases of the kidney are characterized by abnormal nephron morphology with current treatment aimed at symptom control. To understand the mechanisms underlying kidney diseases and achieve the development of novel therapies, a better understanding of how nephrons develop is needed. Although the actin cytoskeleton is critical for cell behaviors …

Artificial Intron Technology To Generate Conditional Knock-Out Mice, Amber N. Thomas-Gordon

Dissertations and Theses (Open Access)

Genetic engineering has been re-shaped by the invention of new tools in modern biotechnology in a way that offers precision and efficiency in modifying the genome at a single nucleotide level and/or allowing precise control of gene expression. Such gene manipulation brings about significant findings and revelations in comprehending more about embryonic development, cellular and physiological functions, and disease pathology. Current methods used to produce conditional knockouts have limitations on conditional allele placement and modification varies among genes in different organisms. Thus, a system for generating conditional alleles with fidelity remains a challenge. My goal was to examine an approach …

Platiscity Of C. Elegans Germline Stem Cells Under Nutritional And Metabolic Stress, Kenneth Trimmer

Dissertations and Theses (Open Access)

Stem cells are integral for tissue maintenance and fertility. Therefore, understanding how stem cells are regulated under stress is imperative. When confronted with acute starvation, stem cells must conserve energy and metabolites to cope with the lack of an external source. Caenorhabditis elegans germline stem cells (GSCs) are an excellent model for studying stem cell properties and regulation as they can divide throughout the life of the organism. While GSCs are an adult stem cell population, their cell cycle structure more closely mimics mouse and human embryonic stem cells with short G1 and long S phases. In this thesis, I …

Phosphorylation Impairs Dicer1 Function To Accelerate Aging And Tumorigenesis In Vivo, Neeraj Aryal

Dissertations and Theses (Open Access)

Altered DICER1 protein levels are associated with developmental disorders, infertility, macular degenerative blindness, aging, and cancer in humans. Recently, post-translational regulation of Dicer1 via phosphorylation has been described in C. elegans. Oscillation of Dicer1 phosphorylation to regulate its activity is essential for germ cell development and embryogenesis in worms. These observations led us to posit that Dicer1 protein levels and activity are under tight regulation for normal mammalian homeostasis. To test whether phosphorylation of Dicer1 regulates its activity in mammals, I generated phospho-mimetic knock-in mouse models by replacing Serines 1712 and 1836 with Aspartic acids individually or together (dual …

Gcn5 Impacts Fgf Signaling At Multiple Levels And Activates C-Myc Target Genes During Early Differentiation Of Embryoid Bodies, Li Wang

Dissertations and Theses (Open Access)

Precise control of gene expression during development is orchestrated by transcription factors, signaling pathways and co-regulators, with complex cross-regulatory events often occurring. Growing evidence has identified chromatin modifiers as important regulators for development as well, yet how particular chromatin modifying enzymes affect specific developmental processes remains largely unclear. Embryonic stem cells (ESCs) are self-renewing, pluripotent, and have the abilities to generate almost all cell types in adult tissues. The dual capacity of ESCs to self-renew and differentiate offers unlimited potential for studying gene regulation events at specific developmental stages in vitro that parallel developmental events during embryogenesis in vivo. …

Investigating The Roles Of Δnp63 As A Suppressor Of Migration, Invasion, And Metastasis, Ramon E. Flores Gonzalez

Dissertations and Theses (Open Access)

Cancer is one of the leading causes of death and disease in the world. Considerable resources are spent to study and understand cancer, with the hope of developing new treatments and eventually cures that will help millions of people. Efforts to understand cancer are hindered by its inherent complexity and instability. Nonetheless, understanding the basics of tumor development and progression are the key to focused on studying the role of ΔNp63 in cancer, a p53 family member known to be involved in epithelial development, microRNA biogenesis, and stem cell maintenance. Using the strength of in vivo mouse models, we found …

Defining The Molecular Networks Necessary For Thymus Fate And Organogenesis, Kaitlin A. Reeh

Dissertations and Theses (Open Access)

The thymus and parathyroid (PT) glands originate from endodermal progenitors in the bilateral third pharyngeal pouches (3^rd pps). By E11.5 during mouse development, cells committed to the thymus lineage express Foxn1 whereas PT-fated cells express Gcm2. While these transcription factors are required for organ-specific differentiation, the exact molecular mechanisms that specify endodermal progenitors to either the thymus or parathyroid lineage are not well defined. Tbx1 is initially expressed throughout the 3^rd pp endoderm, as it is required for segmentation of the pharyngeal apparatus, but is downregulated in the thymus-fated domain by E10.5. Despite the widely held notion …

Merlin Mediated Regulation Of Hair Follicle Morphogenesis, Megan K. Fentress

Dissertations and Theses (Open Access)

Epidermal homeostasis is paramount for the ongoing function of the skin as the primary barrier between a mammalian organism and the external environment. Homeostasis is achieved through a complex and delicate balance of cell death, cell proliferation and cell differentiation. Critical for regeneration and maintenance of the skin are epidermal stem cells. Within the epidermis two distinct stem cell compartments exist, the bulge and interfollicular/basal stem cell niches, which play a central role in the regeneration of the epidermis through self-renewal and contribution to the differentiated cells of the epidermis. The bulge stem cell niche is established early in epidermal …

Elucidating The Role Of Rumi And O-Glucosylation In The Drosophila Eye, Amanda Haltom

Dissertations and Theses (Open Access)

Rumi is a protein O-glucosyltransferase that adds the sugar O-glucose onto the serine in the target sequence C-S-X-S-(P/A)-C found within properly folded EGF repeats. It was first discovered to modify the Drosophila Notch extracellular domain and to be required for Notch signaling in a temperature dependent manner, but other targets of Rumi remained unknown. Several other proteins in the Drosophila proteome harbor multiple consensus sequence highly predictive of O-glucose, including the transmembrane protein Crumbs and the secreted protein Eyes shut (Eys). Both of these proteins are required for proper eye development and mutations in their human homologs …

Impact Of Differentiation Status Of Kidney Progenitors In Wilms Tumor Development, Le Huang

Dissertations and Theses (Open Access)

Wilms tumor is one of the most common solid tumors in children. It is an embryonic cancer of the kidney and is thought to arise from undifferentiated renal mesenchyme. However, the differentiation status of cells in the mesenchyme that can give rise to Wilms tumors is unknown. Gene expression analysis of a large panel of Wilms tumor patients has identified different subsets of Wilms tumors that are distinct in their clinical outcomes and gene expression signatures. These subsets express specific genes that correspond to different stages of differentiation during renal development, suggesting that Wilms tumors may arise from transformed cells …

Sox2-Dependent Transcriptional Control Of Airway Differentiation In The Mouse Lung, Belinda J. Hernandez

Dissertations and Theses (Open Access)

The lung is a highly branched tree-like tubular system that results from more than 20 generations of the conducting airways and consists of 300 million alveoli for gas exchange. Airway branches form via branching morphogenesis and then mature into conducting airways, in which the number and distribution of different cell types need to be precisely controlled. The conducting airways contain four lung cell types: club cells, ciliated cells, basal cells, and neuroendocrine cells.SOX2 is a well-known conducting airway marker. SOX2 is a transcription factor that is known to be important in embryonic development and induction of pluripotent stem cells. We …

P120-Catenin Regulates Rest And Corest, And Modulates Mouse Embryonic Stem Cell Differentiation, Moonsup Lee

Dissertations and Theses (Open Access)

The canonical-Wnt pathway and beta-catenin have been extensively studied to determine their contributions to stem cell biology, but less is known about p120-catenin in the nuclear compartment. P120 is developmentally required as a consequence of its biochemical and functional interactions with cadherins, small-GTPases and transcriptional regulators. We report here that p120-catenin binds to and negatively regulates REST and CoREST, that others have indicated form a repressive complex having diverse key roles in developmental and pathologic gene regulation. We thus provide the first evidence for a direct upstream modulator of REST/CoREST function. Using mouse embryonic stem cells (mESCs), mammalian cell lines, …

Characterization Of Ftsa-Ftsn Interaction During Escherichia Coli Cell Division, [email protected] K. Busiek

Dissertations and Theses (Open Access)

Division of a bacterial cell into two equal daughter cells requires precise assembly and constriction of the division machinery, or divisome. The Escherichia coli divisome includes nearly a dozen essential cell division proteins that assemble at midcell between segregating sister chromosomes. FtsZ, a homolog of eukaryotic tubulin, is the first essential cell division protein to localize at midcell where it polymerizes into a ring-shaped scaffold (Z ring). Establishment of the Z ring is required for recruitment of downstream cell division proteins including FtsA, a cytoplasmic protein that tethers the Z ring to the inner membrane. Following localization of FtsA and …