Developmental Biology Commons^™

Integration Of Bmp And Insulin/Igf-1 Signaling Regulates Multiple Homeostatic Functions In Caenorhabditis Elegans, James F. Clark

Dissertations, Theses, and Capstone Projects

The maintenance of homeostatic functions is key to the survival and well-being of an organism. Regulation of homeostasis relies on varied inputs, both intrinsic and extrinsic, to potentiate a web of interconnected signaling relays. Insulin/IGF-1 signaling (IIS) is a well-known regulator of glucose and lipid metabolism, as well as having far reaching effects in other homeostatic mechanisms. On the other hand, bone morphogenetic protein (BMP), a member of the transforming growth factor beta signaling superfamily, is known for its role in differentiation and development, with only recent studies highlighting potential roles in metabolic homeostasis. Here we elucidate new functions for …

Crispr Knockouts Reveal An Endogenous Role For Ancient Neuropeptides In Regulating Developmental Timing In A Sea Anemone, Nagayasu Nakanishi, Mark Q. Martindale

Biological Sciences Faculty Publications and Presentations

Neuropeptides are evolutionarily ancient peptide hormones of the nervous and neuroendocrine systems, and are thought to have regulated metamorphosis in early animal ancestors. In particular, the deeply conserved Wamide family of neuropeptides—shared across Bilateria (e.g. insects and worms) and its sister group Cnidaria (e.g. jellyfishes and corals)—has been implicated in mediating life-cycle transitions, yet their endogenous roles remain poorly understood. By using CRISPR-Cas9-mediated reverse genetics, we show that cnidarian Wamide—referred to as GLWamide—regulates the timing of life cycle transition in the sea anemone cnidarian Nematostella vectensis. We find that mutant planula larvae lacking GLWamides transform into morphologically normal polyps …

Identification Of Three Required Positive Cis-Regulated Inputs Of The Sea Urchin Pigment Cell Gene Polyketide Synthase 1, Cristina Calestani, Preston Dean, Xiaoman Li

Georgia Journal of Science

Sea urchin pigment cells are single cells of mesodermal origin embedded in the aboral ectoderm. Strongylocentrotus purpuratus polyketide synthase 1 (Sp-PKS1) is required for the biosynthesis of the echinochrome pigment. Evidence suggests that pigment cells are immune cells. In order to reconstruct the gene regulatory network of pigment cells a bottom-up approach combined with comparative genomics has been used in this study. We compared the cis-regulatory regions of five pigment cell genes, Sp-Pks1, flavin monooxygenase 1, 2, and 3 (Sp-Fmo) and sulfotransferase (Sp-Sult), across three different species, Strongylocentrotus purpuratus, Mesocentrotus franciscanus …

Growing Up In Tell El-Amarna: An Examination Of Growth And Non-Specific Stress Indicators In New Kingdom Children., Ashley Elizabeth Shidner

Graduate Theses and Dissertations

The health status of the subadult skeletal remains from the South Tombs Cemetery at Tell el-Amarna were assessed by examining fluctuations in childhood growth and rates of skeletal indicators of physiological stress within a biocultural framework. The long bone standardization method outlined by Goode et al. (1993) was used to compare the South Tombs cemetery’s cross-sectional growth data to subadult samples from other cemeteries during which major social, political, and economic changes were taking place. The comparative subadult samples included the HK43 cemetery from Hierakonpolis (Egypt), the African American Cemetery from Cedar Grove (Arkansas), and the St. Martin’s Churchyard from …

Maternal Angiotensinogen Genotype And Fetal Sex Impact Uteroplacental Function And The Developmental Origins Of Stress-Induced Hypertension, Jessica Faith Hebert

Dissertations and Theses

Fetal growth restriction (FGR) is a common and potentially life-threatening complication that affects 5-10% of human pregnancies. Maternal genetic predisposition and fetal male sex are known risk factors, but the underlying mechanisms are unknown. To study a known maternal genetic risk factor and the impact of fetal sex, we employed a published transgenic (TG) mouse model, which was designed to mimic a common human angiotensinogen (AGT) promoter variant associated with a 20% increase in circulating AGT levels. We hypothesized that TG dams would deliver growth restricted pups and that the underlying mechanism would be related to differences in maternal uterine …

Zinc Sunscreens Affect Development Of Strongylocentrotus Purpuratus Embryos, Brittany E. Cunningham, Nikki L. Adams

Master's Theses

The growing popularity of physical sunscreens will also lead to an increased release of the ingredients from zinc oxide (ZnO) sunscreens into marine environments. Though zinc (Zn) is a necessary micronutrient in the ocean, greater than natural Zn concentrations are being released into marine environments by use of sunscreens. The extent of the consequences of the addition of Zn to the ocean are not fully understood. We investigated effects of materials released by zinc oxide (ZnO) sunscreens on the development of California purple sea urchin, Strongylocentrotus purpuratus. Embryos developed in various concentrations of Zn, the sources of which included …

Examining The Roles Of Genetic And Environmental Factors In Drosophila Melanogaster Hematopoiesis And Innate Immune System, Minkyung Lee

Student Theses and Dissertations

Nearly 24 million people are affected by autoimmune diseases in the United States. Main causes of autoimmune diseases have been attributed to genetic predisposition and environmental exposure to chemicals such as hormones and pesticides. Due to the large population that are affected by autoimmune diseases, it is critical to understand the mechanisms behind them. In this study, we sought to explore both genetic and environmental factors that affect hematopoiesis, or the formation of specific blood cells, and immune system in Drosophila melanogaster. As Drosophila melanogaster have conserved pathways of hematopoiesis as humans, they were used as the model organism …

Egfr Polymorphisms In Drosophila Melanogaster, Stacie Chue, Neha Mehta, Samantha Poon, Heather Trazino

Publications and Research

No abstract provided.

Investigating Interspecific And Intraspecific Variation In Lung Development In Amphibians, Courtney Neumeyer

Masters Theses, 2010-2019

Amphibians occupy an intermediate phylogenetic position between fish and tetrapods, making amphibians an essential model for understanding the evolution of air breathing organs in vertebrates. Amphibians have a uniquely biphasic life style allowing them to occupy aquatic and terrestrial habitats and to use multiple organs for gas exchange at different stages of life. This initial independence from lung breathing means that amphibians are developing their lungs while they are using them, which opens up the possibility that their rate of lung development is controlled in part by their breathing behavior. As such, amphibians provide a starting point for examining the …

Characterizing Epigenetic Regulation In The Developing Chicken Retina, Bejan Abbas Rasoul

Masters Theses, 2010-2019

The retina, the sensory neuronal tissue within the eye, is composed of three layers of neuronal cells connected by two synaptic layers lining the inside of the anterior portion of the eye. Multipotent retinal precursor cells are genetically homogeneous and differentiate into mature retinal neurons due to differential gene expression. Differences in gene expression have been correlated with epigenetic modifications such as DNA methylation. DNA methylation of upstream regulatory elements is associated with transcriptional silencing of gene expression. Years of research in retinal development has identified the numerous genes expressed during the main steps of retinal development, however, it is …

An Examination Of Preimplantation Embryos And Endometrium Developed During Induced Aluteal Cycles In The Mare, Chelsey Audra Leisinger

LSU Doctoral Dissertations

Changes to the embryonic environment that occur within the first few days of development can have significant effects on subsequent fetal development. The following studies investigate the effects of progesterone-deprivation during the early preimplantation period in the mare. The first study described embryo morphology (diameter, stage, and quality grade) collected from mares with induced aluteal cycles. The second study evaluated the effect of induced aluteal cycles on the future fertility of embryo collections as a potential method for cycle manipulation of embryo donor mares. The third study characterized embryonic and endometrial transcript expression of progesterone-mediated transcripts as well as those …

Low Hemodynamic Loading Alters Heart Morphogensis In E8.5 To E9.5 Mouse Embryos, Tanner Gerard Hoog

Graduate Theses/Dissertations

Hemodynamic loading, the force exerted on the cardiovascular walls as blood circulates, has been shown to alter heart morphology in chick and zebrafish embryos, but has yet to be shown to singly influence mouse heart development. Defects of heart morphology found in model organisms with physically altered hemodynamics resemble the aberrations seen in human congenital heart disease and are therefore crucial to understand in a mammalian model. In the present study, hemodynamic loading was altered by lowering the hematocrit of early stage mouse embryos. This was accomplished by injecting acrylamide and TEMED into the blood islands of cultured embryos to …

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 …

In Vivo Structure-Function Analysis Of Drosophila Robo1, An Axon Guidance Receptor Critical For Midline Repulsive Signaling In The Embryonic Central Nervous System, Haley Brown

Graduate Theses and Dissertations

The repellant ligand Slit and its Roundabout (Robo) family receptors regulate many aspects of axon guidance in bilaterians, including midline crossing of axons during development of the embryonic CNS. Slit proteins are produced by midline cells and signal through Robo receptors expressed on the surface of axonal growth cones to repel axons from the midline. Disruption of Slit-Robo signaling causes ectopic midline crossing phenotypes in the CNS of a broad range of animals, including insects and vertebrates.

Drosophila Robo1 has a conserved ectodomain structure of five immunoglobulin-like (Ig) domains plus three fibronectin (FN) repeats. By utilizing a genomic rescue construct …

Investigating The Molecular Function Of Akirin During Skeletal Myogenesis In Drosophila Melanogaster, Kristina Rowland

Master of Science in Integrative Biology Theses

The specification and differentiation of muscle precursor cells, or myoblasts, by the action of the mesodermal and muscle transcription regulator Twist is a key event in the formation of the Drosophila larval musculature. Akirin, a highly conserved nuclear protein, appears to play a critical role in the regulation of Twist-dependent gene expression during mesodermal specification and muscle development. Specifically, Akirin serves as a cofactor to promote interactions between regulatory transcription factors and multisubunit Brahma SWI/SNF-class chromatin remodeling complex to impact gene expression across varying targets. Using a genetic interaction screen in Drosophila, we have begun to identify other Akirin …

Diurnal And Developmental Differences In Gene Expression Between Adult Dispersing And Flightless Morphs Of The Wing Polymorphic Cricket, Gryllus Firmus: Implications For Life-History Evolution, Anthony J. Zera, Neetha Nanoth Vellichirammal, Jennifer A. Brisson

Anthony Zera Publications

The functional basis of life history adaptation is a key topic of research in life history evolution. Studies of wing polymorphism in the cricket Gryllus firmus have played a prominent role in this field. However, prior in-depth investigations of morph specialization have primarily focused on a single hormone, juvenile hormone, and a single aspect of intermediary metabolism, the fatty-acid biosynthetic component of lipid metabolism. Moreover, the role of diurnal variation in life history adaptation in G. firmus has been understudied, as is the case for organisms in general. Here, we identify genes whose expression differs consistently between the …

Genetic Basis Of Larval Crystal Cell Quantity Variation In The Drosophila Genetic Reference Panel (Dgrp), Brian Tang

Student Theses and Dissertations

Crystal cells are one of three requisite hemocytes that take part in fighting infection and wound healing in Drosophila melanogaster (common fruit flies). The developmental genetics of crystal cell formation is only beginning to be discovered. To address this question, we performed a Genome-Wide Association Study (GWAS) on larval crystal cell number from 78 isolines of the Drosophila Genetic Reference Panel (DGRP) collection. The DGRP consists of naturally caught fruit flies that are inbred to near homozygosity with completely sequenced genomes. By placing the wandering third instar larvae under heatshock, a process that induces the melanization of crystal cells, …

Stimulating Canonical Wnt Signaling In Pituitary Progenitors Inhibits Differentiation Of Hormone Cell Types, Tanner F. Coleman

Senior Theses

The mouse pituitary gland secretes hormones that regulate many physiological processes including growth, stress response, and reproduction. The canonical WNT signaling pathway, activation of which results in nuclear accumulation of β-CATENIN and transcription of target genes including LEF1, is crucial for proper development of the pituitary gland. Pituitary progenitors that lack β-CATENIN at embryonic day of development 8.5 (E8.5) cannot form three of the six cell types of the anterior pituitary that produce growth hormone (GH), thyroid stimulating hormone (TSH), and prolactin (PRL). Additionally, stimulating canonical WNT signaling through creation of degradation-resistant β-CATENIN at E9.5 causes pituitary tumors and results …

Maternal Protein Restriction (Mpr): A Risk Factor For Acute Respiratory Distress Syndrome (Ards), Reza Khazaee

Western Research Forum

Background: Acute respiratory distress syndrome (ARDS) is defined as severe lung dysfunction. The lung impairments in ARDS result from alterations to pulmonary surfactant; a lipid-protein mixture coating the inside of the lung and maintains the lungs’ ability to expand easily. Due to a lack of effective pharmacological therapies mortality associated with ARDS is over 30%. Our research focuses on risk factors that indicate a susceptibility to the disease, which could provide new and early therapeutic options. One such potential risk factor is Maternal Protein Restriction (MPR). MPR is defined by low birth weight and contributes to a variety of adult-onset …

Cloning And Spatiotemporal Expression Of Xenopus Laevis Apolipoprotein Ci, Jyotsna Sridharan, Tomomi Haremaki, Daniel C. Weinstein

Publications and Research

Apolipoprotein CI (ApoCI) belongs to the Apolipoprotein superfamily, members of which are involved in lipid transport, uptake and homeostasis. Excessive ApoCI has been implicated in atherosclerosis and Alzheimer’s disease in humans. In this study we report the isolation of Xenopus laevis apoCI and describe the expression pattern of this gene during early development, using reverse transcription polymerase chain reaction and whole mount in situ hybridization. Xenopus apoCI is enriched in the dorsal ectoderm during gastrulation, and is subsequently expressed in sensory placodes, neural tube and cranial neural crest. These data suggest as yet uncharacterized roles for ApoCI during early vertebrate …