Developmental Biology Commons^™

Chromatin-Signaling Axis Orchestrates The Formation Of Germline Stem Cell Differentiation Niche In Drosophila, Maitreyi Upadhyay

Legacy Theses & Dissertations (2009 - 2024)

Stem cells have the unique capability of self-renewing into stem cells and differentiating into several terminal cell types. Loss of either of these processes can lead to aging, progression towards degenerative diseases and cancers. Insight into how self-renewal and differentiation are regulated will have tremendous therapeutic impact. Drosophila is an excellent model system for stem cell study due to the availability of various mutants, markers and RNAi technology. In order to study stem cell biology, we use female Drosophila gonads, whose stem cell population – the germline stem cells (GSCs) gives rise to gametes.

Retinoic Acid Receptor Isoform-Specific Control Of Mouse Salivary Gland Development And Regeneration, Kara Desantis

Legacy Theses & Dissertations (2009 - 2024)

Controlled expansion and differentiation of progenitor cell populations is essential for organogenesis followed by continued maintenance of the population into and through adulthood. As the K5+ basal cell population is regulated by retinoic acid signaling, we interrogated the contribution of specific RAR isoforms to the regulation of these cells during submandibular salivary gland (SMG) organogenesis and regeneration. Retinoic acid has previously been shown to be involved in the development of the salivary gland, and recently, lack of retinoid signaling has been shown to impact the K5+ population of basal progenitor cells. Since retinoic acid is known to exert stimulatory effects …

Why Doesn’T A Mother Reject A Genetically Different Fetus?, Devora Krumholtz

The Science Journal of the Lander College of Arts and Sciences

Many basic multicellular organisms possess some form of immune response to protect themselves against the invasion of foreign objects. It was not until British scientist, Peter Medawar proposed a fundamental question that changed the way researchers studied the maternofetal relationship. A fetus, being genetically different from its mother should be rejected by the maternal immune system, however, it is not. Researchers have since discovered and developed several mechanisms that aim to explain how the maternal immune system prevents fetal rejection. The formation of a mechanical barrier, general and local suppression of the maternal immune system, and a shift in cytokine …

The Folic Acid Metabolism Gene Mel-32/Shmt Is Required For Normal Cell Cycle Lengths In Caenorhabditis Elegans, Kalin D. Konrad, Raquel A. Campbell, Vanessa Thiel, Jessica Sullivan-Brown

Biology Faculty Publications

Neural tube defects are common and serious birth defects in which the brain and/or spinal cord are exposed outside the body. Supplementation of foods with folic acid, an essential vitamin, is linked to a lower risk of neural tube defects; however, the mechanisms by which folic acid influence neural tube defect risk are unclear. Our research seeks to identify the basic cellular roles of known folic acid metabolism genes during morphogenesis using the roundworm Caenorhabditis elegans (C. elegans) as a simple model system. Here, we used live imaging to characterize defects in embryonic development when mel-32 is depleted. mel-32 is …

Jak/Stat Signaling Regulates Gametogenesis And Age-Related Reproductive Maintenance, Michelle Suzanne Giedt

Theses and Dissertations--Biology

Cell signaling is central to integration of internal and external cues that regulate development and homeostasis. Most development is thought of as pre-adult, but limited developmental processes occur in adults. Gametogenesis incorporates elements of both these facets, with a distinct developmental plan for gamete synthesis which is regulated by integration of homeostatic inputs such as nutrient status, and environmental cues. Signaling pathways integrate and transduce information from these cues to evoke a response. A decline in homeostasis and subsequent cues occurs over time, in the case of reproductive tissues leading to a progressive loss of fertility. The Janus Kinase and …

The Encyclopedia Of North American Drosophilids Volume 1: Drosophilids Of The Midwest And Northeast, Thomas Werner, Tessa Steenwinkel, John Jaenike

Open Access Books

The Encyclopedia of North American Drosophilids: Volume 1: Drosophilids of the Midwest and Northeast provides an introduction to the flies of the family Drosophilidae of the Midwest and Northeast of the United States, as well as nearby regions in Canada. The book strives to facilitate identification of most of the drosophilid species in this region and provides remarks on interesting aspects of their biology and suggestions for future research on them. The book is intended for researchers, teachers, and students wishing to discover the diversity of these flies.

Version 4 is a major update that covers new species and includes …

Comparative Phylogeography, Taxonomy, And Neuroanatomy Of Montane Chameleons In The Albertine Rift, Central Africa, Daniel Hughes

Open Access Theses & Dissertations

How do traits vary across the tree of life? Our ability to address this question is diminished if: A taxonomic group has a poorly sampled phylogeny, a species goes extinct before their systematic position is resolved, or a trait is inadequately characterized for detailed studies. In the current era of mass extinction, it is imperative to not only accelerate species discovery through traditional studies in taxonomy and expeditionary research, but also to increase rescue efforts for all types of data before poorly understood species and potentially undescribed traits are lost. Here, an integrative taxonomic approach was used and novel methods …

Pitx1 Regulates Cement Gland Development In Xenopus Laevis Through Activation Of Transcriptional Targets And Inhibition Of Bmp Signaling, Ye Jin, Daniel C. Weinstein

Publications and Research

The cement gland in Xenopus laevis has long been used as a model to study the interplay of cell signaling and transcription factors during embryogenesis. It has been shown that an intermediate level of Bone Morphogenetic Protein (BMP) signaling is essential for cement gland formation. In addition, several transcription factors have been linked to cement gland development. One of these, the homeodomain-containing protein Pitx1, can generate ectopic cement gland formation; however, the mechanisms underlying this process remain obscure. We report here, for the first time, a requirement for Pitx proteins in cement gland formation, in vivo: knockdown of both pitx1 …

Elucidating The Role Of Nidogen In The Fusion Of The Choroid Fissure, Nicholas W. Carrara

Theses and Dissertations--Biology

In the developing embryo, the timely fusion of opposing epithelial sheets into one uniform layer denotes the completion of several developmental events. Failure of this epithelial sheet fusion event (ESF) within the choroid fissure (CF) is associated with the congenital disorder Ocular Coloboma, and is one of the leading causes of pediatric blindness. A requirement for a highly coordinated dismantling of the basement membrane (BM) to allow for fusion to occur is undoubted, however the underlying mechanisms of this process are poorly understood. Due to its BM crosslinking capabilities, I have hypothesized that the regulation of nidogen plays a crucial …

Wnt Secretion Proteins Modulate Rankl-Induced Expression Of Aire In Thymic Epithelial Cells, Daniel Pollack

Dissertations and Theses

Thymic epithelial cells (TEC) are essential for a proper adaptive immune response by regulating thymocyte development and establishing central tolerance. In the thymus, TECs differentially express Wnt proteins, which activate canonical and non-canonical Wnt signaling pathways. Wnt signaling is thought to regulate cell survival, proliferation, and development although the direct molecular mechanisms in TECs have yet to be elucidated. The inducible inhibition of canonical Wnt signaling with Dkk1 leads to a rapid loss of TEC progenitors as well as a decline in mature Aire-expressing mTECs. Therefore, we explore the role of Wnt ligands potentially responsible for stimulating and/or regulating Wnt …

Bone Marrow Derived Progenitor Cells And Their Contributions To The Thymic Stroma, Mohammed Hoque

Dissertations and Theses

The thymus serves as the primary lymphoid organ responsible for the development and selection of a self-tolerant T cell repertoire. In paradox to its critical functions for the adaptive immune response, the thymus undergoes a profound age associated decline beginning in early adult life resulting in significant decline in T-cell function.Thymic epithelial cells (TECs) are the most critical component of the thymic microenvironment and undergo rapid turn-over, so understanding the cellular mechanisms responsible for the maintenance of TEC number and organization will be critical in counteracting age associated involution, particularly in cancer patients, due to enhanced degeneration in response to …

Appropriate Preconditioning Of The Uterine Endoplasmic Reticulum Stress Response Inhibits Preterm Labor, Judith Ann Ingles

Wayne State University Dissertations

Introduction: In this study, we are testing the overarching hypothesis that preconditioning the myometrial UPR allows for the maintenance of non-apoptotic CASP3 activity and thus sustains uterine quiescence. We have previously demonstrated that the pregnant uterus facilitates uterine quiescence through UPR mediated activation of non-apoptotic CASP3, yet the mechanism in which CASP3 utilizes to avoid its apoptotic cell fate is unresolved. There is a growing body of evidence including our own that demonstrates remote and direct preconditioning with minor stresses propagates cytoprotective mechanisms that allow for the avoidance of apoptotic cell death upon exposure to a subsequent more damaging stress, …

Using The Frog Epidermis To Uncover Desmosome Function And Regulation In The Developing Embryo, Navaneetha Krishnan Bharathan

Theses and Dissertations

The desmosome is one of the major cell adhesion junctions found in the epithelia, heart, and hair follicle. Described as a “rivet” that hold cells together, it provides these tissues with the integrity to withstand the tremendous forces they face in everyday life. Defects in this junction can lead to devastating diseases where patients are susceptible to skin infections and cardiovascular defects. Limited treatments exist for diseases of the desmosome, and strategies do not target all symptoms. Therefore, delineating the function and regulation of desmosomes is of paramount importance for the development of prevention and treatment strategies. The Xenopus laevis …

Chromodomain Helicase Dna Binding Protein 1 (Chd1) Is Required For Orofacial Development In Xenopus, Brent Wyatt

Theses and Dissertations

Abnormalities affecting orofacial development are some of the most common, expensive, and devastating birth defects. Children born with such defects may experience difficulties with eating, breathing, and speech and in addition, these defects often require multiple surgeries to correct them. Therefore, it is critical to understand how the orofacial region develops in order to better treat and prevent these types of birth defects. Xenopus laevis has emerged as a strong model in which to examine orofacial development and was utilized here to investigate the cellular and molecular mechanisms underlying the complex development of the orofacial region. Retinoic acid is one …

Stat3 In The Regulation Of Brown Adipocyte Differentiation, Marc Cantwell

Theses and Dissertations

Thermogenic fat is a promising target for new therapies in diabetes and obesity. Understanding how thermogenic fat develops is important to develop rational strategies to treat obesity. Previously, we have shown that Tyk2 and STAT3, part of the JAK-STAT pathway, are necessary for proper development of classical brown fat. Using primary preadipocytes isolated from newborn mice we demonstrate that STAT3 is required for differentiation and robust expression of Uncoupling Protein 1. We also confirm that STAT3 is necessary during the early induction stage of differentiation and is dispensable during the later terminal differentiation stage. Without STAT3, the brown preadipocytes have …