Developmental Biology Commons^™

Sunergos1, A Lotus Japonicus Gene Required For Proper Accommodation Of Rhizobial Infection, Hwi Joong Yoon

Electronic Thesis and Dissertation Repository

Here, I characterize a symbiotic mutant of Lotus japonicus, called sunergos1 (suner1), which originated from a har1-1 suppressor screen. I have shown that suner1 supports epidermal infection by rhizobia and initiates nodule primordia organogenesis as in wild-type. However, the infection process is temporarily stalled, such that infection threads fail to ramify within the root cortex and timely release of bacteria inside the nodule primordia cells does not occur. This symbiotic defect is ephemeral and with additional time, functional nodules are formed. Using a combined approach involving map-based cloning and next-generation sequencing, I have shown that the suner1 …

Characterizing The Heavy Metal Chelator, Tpen, As A Ca2+ Tool In The Mammalian Oocyte, Robert A. Agreda Mccaughin

Masters Theses 1911 - February 2014

N,N,N’,N’-tetrakis-(2-Pyridylmethyl) ethylenediamine (TPEN) is a heavy metal chelator with high affinity for zinc. TPEN causes important responses in mammalian eggs. For example, these eggs are arrested at the MII stage by the Endogenous Mitotic Inhibitor 2 (Emi2), which prevents activation of the Anaphase Promoting Complex (APC) and degradation of Cyclin B. By chelating zinc, TPEN inactivates Emi2 and eggs undergo spontaneous exit of meiosis and egg activation. TPEN chelates Ca²⁺ with lower affinity, although in the Endoplasmic Reticulum (ER), where Ca²⁺ concentrations are high, TPEN may sequester Ca²⁺ preventing release into the cytoplasm. Initial exposure of TPEN …

Examining The Functional Role Of Dprl-1 In Drosophila Melanogaster, John Valenzuela

Summer Research

The Phosphatase of Regenerating Liver (PRL) family of proteins control cell growth, motility and proliferation. They have been shown to elevate the levels of these functions, leading to an increase in cancer metastasis (“malignancy”), when they are overexpressed. The goal of this experiment is to knockout PRL gene expression to examine the general function of PRL proteins. Drosophila melanogaster have only one copy of the PRL gene (dPRL-1), as opposed to humans and other mammals, which have 3. Thus, using P-element imprecise excision to create mutant strains either fully lacking or with decreased function of the dPRL-1 protein, …

Embryonic Stem Cells Are Redirected To Non-Tumorigenic Epithelial Cell Fate By Interaction With The Mammary Microenvironment, Corinne A. Boulanger, Robert D. Bruno, David L. Mack, Monica Gonzales, Nadia P. Castro, David S. Salomon, Gilbert H. Smith

Medical Diagnostics & Translational Sciences Faculty Publications

Experiments were conducted to redirect mouse Embryonic Stem (ES) cells from a tumorigenic phenotype to a normal mammary epithelial phenotype in vivo. Mixing LacZ-labeled ES cells with normal mouse mammary epithelial cells at ratios of 1:5 and 1:50 in phosphate buffered saline and immediately inoculating them into epithelium-divested mammary fat pads of immune-compromised mice accomplished this. Our results indicate that tumorigenesis occurs only when normal mammary ductal growth is not achieved in the inoculated fat pads. When normal mammary gland growth occurs, we find ES cells (LacZ+) progeny interspersed with normal mammary cell progeny in the mammary epithelial structures. We …

A Path To Success? A Review Of Evolution, Development, And The Predictable Genome By David L. Stern, Hope Hollocher, Charles H. Pence, Grant Ramsey, Michelle M. Wirth

Faculty Publications

No abstract provided.

The Xenopus Lefty (Xlefty) Prodomain Negatively Regulates Xlefty Activity And Is Necessary For Proper Xlefty Secretion, Adrian Amelio Vasquez

Wayne State University Theses

In vertebrates, the TGF #914; superfamily of secreted peptides are stringently regulated since they are responsible for multiple cell processes and behaviors that give rise to the proper patterning of embryonic tissues. Examples of members of the TGF #914; superfamily are Nodal and Lefty. Dysregulation of these proteins can lead to many diseases and developmental syndromes in humans.

Lefty functions by antagonizing Nodal an essential organizer signal that patterns dorsal mesoderm and the embryonic axes. Loss of Lefty expression results in excess Nodal signaling which has been shown to cause several perturbations including metastatic cancer. Although studies have clearly shown …

Genetic Diversity In Populations Of Epiphanes Chihuahuaensis (Rotifera: Monogononta) In The Northern Chihuahuan Desert, Diego E. Reyes

Open Access Theses & Dissertations

1. Cryptic speciation in zooplankton is a phenomenon that has been recently gaining much attention. This is due in part to advances in molecular techniques which help in the identification of morphologically indistinct species. Organisms that have been traditionally believed to have cosmopolitan distributions are being found to be composed of cryptic species complexes with high levels of genetic divergence among lineages.

2. Epiphanes chihuahuaensis is a member in the Epiphanes senta species complex. In a previous study by Schröder & Walsh (2007), genetic data, along with morphological and reproductive isolation data were employed to help delineate four species within …

The Dn2 Myeloid-T (Dn2mt) Progenitor Is A Target Cell For Leukemic Transformation By The Tlx1 Oncogene, Lynnsey A. Zweier-Renn, Irene Riz, Teresa S. Hawley, Robert G. Hawley

Anatomy and Regenerative Biology Faculty Publications

Introduction: Inappropriate activation of the TLX1 (T-cell leukemia homeobox 1) gene by chromosomal translocation is a recurrent event in human T-cell Acute Lymphoblastic Leukemia (T-ALL). Ectopic expression of TLX1 in murine bone marrow progenitor cells using a conventional retroviral vector efficiently yields immortalized cell lines and induces T-ALL-like tumors in mice after long latency.

Methods: To eliminate a potential contribution of retroviral insertional mutagenesis to TLX1 immortalizing and transforming function, we incorporated the TLX1 gene into an insulated self-inactivating retroviral vector.

Results: Retrovirally transduced TLX1-expressing murine bone marrow progenitor cells had a growth/survival advantage and readily gave rise to immortalized …

Analysis Of The Minimal Promoter From The Hatching Enzyme A Gene, Anna Matejczyk

Master's Theses

Hatching, defined as a biochemical or biophysical mechanism that allows the embryo to leave its protective envelope, is found in most animals. In fish, reptiles and amphibians, mostly oviparous animals, this means the emergence of the embryo from an egg. In mammals, viviparous animals, hatching is performed by the blastocyst in order to shed the zona pellucida.

Fish, an oviparous animal, takes advantage of a biochemical mechanism in order to hatch and emerge from their chorion, or egg envelope. The mechanism includes the use of hatching enzymes that are secreted in order to digest the envelope membrane. The genes controlling …

Exploring Potential Risk Factors Of Fetal Origins Of Diabetes: Maternal Stressors During Pregnancy And Birth Outcomes Among Women In A Hospital In The Municipality Of Caguas, Puerto Rico, Juan Pablo Arroyo

USF Tampa Graduate Theses and Dissertations

Puerto Rico has the highest prevalence of type 2 diabetes, low birth-weight, and the second highest prevalence of preterm-birth in all the U.S. and its non-incorporated territories. These conditions are related. Birth-weight at both ends of the spectrum and preterm-birth are associated with an increased risk for developing type 2 diabetes and immune-inflammatory dysregulations. Maternal psychosocial stressors during pregnancy have also been recognized as potential risk factors for type 2 diabetes, and have been consistently associated with preterm-birth and low birth-weight across populations. Current evidence points toward epigenetic fetal metabolic-programming as the mechanism that underlies the increased risk for the …

A Role For Dynamin-Dependent Endocytosis During Drosophila Gastrulation, Marissa Kay Kuhl

Electronic Theses and Dissertations

Gastrulation, a process conserved among many higher organisms, is the directed migration of cells into layers that will establish various tissues targeted to become anatomical structures. This process is accomplished through another conserved morphogenetic event, known as cell intercalation. Early in development, this movement of cells within an organized tissue leads to unique cellular arrangements where neighboring cells contract their shared interfaces in order to meet at a shared vertex. In this thesis, I present work that demonstrates a requirement for Dynamin-dependent endocytosis during these contraction events. Using quantitative analysis, I have identified varied cell behaviors during experiments which knockdown …

Keratin Gene Expression Profiles After Digit Amputation In C57bl/6 Vs. Regenerative Mrl Mice Imply An Early Regenerative Keratinocyte Activated-Like State, Chia-Ho Cheng, John Leferovich, Xiangming Zhang, Khamilia Bedelbaeva, Dmitri Gourevitch, Cathy J. Hatcher, Craig T. Basson, Ellen Heber-Katz, Kenneth A. Marx

PCOM Scholarly Papers

Mouse strains C57BL/6 (B6) and MRL were studied by whole mouse genome chip microarray analyses of RNA isolated from amputation sites at different times pre-and postamputation at the midsecond phalange of the middle digit. Many keratin genes were highly differentially expressed. All keratin genes were placed into three temporal response classes determined by injury/preinjury ratios. One class, containing only Krt6 and Krt16, were uniquely expressed relative to the other two classes and exhibited different temporal responses in MRL vs. B6. Immunohistochemical staining for Krt6 and Krt16 in tissue sections, including normal digit, flank skin, and small intestine, and from normal …

Nutritional Intervention Restores Muscle But Not Kidney Phenotypes In Adult Calcineurin Aα Null Mice, K. Madsen, R. N. Reddy, S. R. Price, C. R. Williams, Jennifer L. Gooch

PCOM Scholarly Papers

Mice lacking the α isoform of the catalytic subunit of calcineurin (CnAα) were first reported in 1996 and have been an important model to understand the role of calcineurin in the brain, immune system, bones, muscle, and kidney. Research using the mice has been limited, however, by failure to thrive and early lethality of most null pups. Work in our laboratory led to the rescue of CnAα-/- mice by supplemental feeding to compensate for a defect in salivary enzyme secretion. The data revealed that, without intervention, knockout mice suffer from severe caloric restriction. Since nutritional deprivation is known to significantly …

Comparison Of Ectoparasitic Mite Loads Between Gonochoristic (Aspidoscelis Marmorata) And Parthenogenic (A. Tesselata) Syntopic Whiptail Lizards (Teiidae) From The Northern Chihuahuan Desert Of Trans-Pecos, Texas, William Dawson Lukefahr

Open Access Theses & Dissertations

The objective of this study was to compare the ectoparasitic loads between two syntopic whiptail lizard species (Teiidae) that differ in their reproductive modes; Aspidoscelis marmorata (bisexual) and A. tesselata (unisexual). The study site was located on Indio Mountains Research Station (IMRS) in a Chihuahuan Desert Scrub landscape in Hudspeth County, Texas. Previous studies conducted at IMRS showed the two species having similar diets, morphology, and reproductive characteristics, but fluctuated in nematode loads. No comparative study of ecotoparasitic mites (Eutrombicula alfreddugesi) between the two species has ever been done.

Aspidoscelis marmorata (n = 141) and A. tesselata (n = 144) …

Developmental Plasticity In Response To Familiar And Unfamiliar Predators In The Mud Snail, Ilyanassa Obsoleta, Kelly Strickland Hoolihan

Dissertations, Theses, and Masters Projects

No abstract provided.

Post-Translational Modification Regulates Heterogeneous Nuclear Ribonucleoprotein K Function During Axon Outgrowth In Xenopus Laevis, Erica J. Hutchins

Legacy Theses & Dissertations (2009 - 2024)

The RNA-binding protein, heterogeneous nuclear ribonucleoprotein K (hnRNP K), is required for axon outgrowth. Its suppression in Xenopus embryos causes defects in the translation of mRNAs of multiple cytoskeletal genes. Studies in cell lines have established that hnRNP K shuttles between the nucleus and the cytoplasm to bind and regulate the fates of its target RNAs, from splicing to export and translation. At each step, hnRNP K is regulated through post-translational modifications that alter its nucleic acid and protein interactions, and subcellular localization. Precisely how this happens in developing neurons to coordinate cytoskeletal gene expression with the extracellular signals directing …

Mechanisms Of Nitrogenous Waste Excretion During The Complex Life Cycle Of The Sea Lamprey (Petromyzon Marinus), James M. Neal Mr.

Theses and Dissertations (Comprehensive)

Sea lampreys (Petromyzon marinus) are a phylogenetically ancient jawless fish, with a multi-staged life cycle characterized by a prolonged suspension-feeding larval stage, which is followed by metamorphosis into parasitic lampreys that feed on the protein-rich blood of fishes. The switch from a nutrient poor to protein-rich diet in the sea lamprey is associated with an increased capacity to deaminate excess amino acids and to excrete ammonia and urea following metamorphosis. The focus of this thesis was to determine if changes in nitrogenous waste transporter protein abundance facilitate ammonia and urea excretion during different stages of the sea lamprey …

Impairment Of Trkb-Psd-95 Signaling In Angelman Syndrome, Cong Cao, Mengia S. Rioult-Pedotti, Paolo Migani, Crystal J. Yu, Rakesh Tiwari, Keykavous Parang, Mark R. Spaller, Dennis J. Goebel, John Marshall

Pharmacy Faculty Articles and Research

Angelman syndrome (AS) is a neurodevelopment disorder characterized by severe cognitive impairment and a high rate of autism. AS is caused by disrupted neuronal expression of the maternally inherited Ube3A ubiquitin protein ligase, required for the proteasomal degradation of proteins implicated in synaptic plasticity, such as the activity-regulated cytoskeletal-associated protein (Arc/Arg3.1). Mice deficient in maternal Ube3A express elevated levels of Arc in response to synaptic activity, which coincides with severely impaired long-term potentiation (LTP) in the hippocampus and deficits in learning behaviors. In this study, we sought to test whether elevated levels of Arc interfere with brain-derived neurotrophic factor (BDNF) …

Substituting The Senses, Mirko Farina, Julian Kiverstein, Andy Clark

Mirko Farina

Sensory substitution devices are a type of sensory prosthesis that (typically) convert visual stimuli transduced by a camera into tactile or auditory stimulation. They are designed to be used by people with impaired vision so that they can recover some of the functions normally subserved by vision. In this chapter we will consider what philosophers might learn about the nature of the senses from the neuroscience of sensory substitution. We will show how sensory substitution devices work by exploiting the cross-modal plasticity of sensory cortex: the ability of sensory cortex to pick up some types of information about the external …

Functional Significance Of Ilk-Elmo2 Interactions In Epidermal Keratinocytes, Ernest Ho

Electronic Thesis and Dissertation Repository

The epidermis consists of a basal layer of undifferentiated keratinocytes and multiple suprabasal layers of differentiated keratinocytes. Undifferentiated keratinocytes are adherent and highly motile, whereas differentiated keratinocytes are comparatively less motile and downregulate cell attachments to the extracellular matrix. Integrin-linked kinase (ILK) is a scaffold protein implicated in the regulation of many cellular functions in keratinocytes, including cell attachment, migration, phagocytosis, and protein trafficking. To determine the mechanisms by which ILK is involved in these processes, I sought to identify other proteins which may interact with ILK in keratinocytes. I identified Engulfment and Cell Motility 2 (ELMO2) to interact with …