Download or read book Analysis of Axon Guidance in the Embryonic Central Nervous System of Drosophila Melanogaster written by Vicki L. McGovern and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: The goal of developmental neurobiology is to understand how a complex nervous system is wired. During development of the central nervous system (CNS) neural connections are assembled in a highly stereotyped fashion. How do axons find their targets with such accuracy? We know that axon migration is direct by attractive and repulsive guidance cues located in the extracellular environment. While many guidance molecules have been identified, we are only just beginning to understand the mechanisms of axon guidance. In order to identify additional genes involved in axon guidance and CNS development we performed a misexpression screen. Using P-elements and the UAS/GAL4 system, transcription of endogenous genes was induced in the embryonic CNS. Misexpression phenotypes were then identified immunohistochemically with two monoclonal antibodies: BP102, a general axon marker, and 1D4, which labels a subset of axon pathways. Over 4100 individual P-element insertion lines were screened. Twenty-five insertions corresponding to 18 genes resulted in misexpression phenotypes. Genes involved in axon guidance, embryonic patterning, and cell cycle regulation were identified. Several transcription factors that have not been previously implicated in CNS development were isolated and characterized as well. The identification of these transcription factors is intriguing since little is known about the transcriptional regulation of axon guidance genes. Additionally, we have studied the regulation of the previously identified guidance molecule Commissureless (Comm). Comm is necessary for proper axon guidance at the CNS midline of the Drosophila embryo. In the absence of Comm, commissural axons fail to cross the midline and instead make ispilateral projections on their respective sides of the midline. Using mosaic analysis, we have identified a cell autonomous neuronal requirement for Comm. Clones containing mutant alleles of comm formed commissural projections at a statistically significant reduced frequency when compared to wild type clones. This result suggests that regulation of Comm expression in neurons is critical for Comm's function in axon guidance at the CNS midline. These studies have both advanced the understanding of the regulation of Comm, and have identified new potential regulators of guidance molecules.
Download or read book Analysis of the Role of the Roundabout Receptors in Axon Guidance in the Embryonic Central Nervous System of Drosophila Melanogaster written by Julie Hayner Simpson and published by . This book was released on 2001 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis of the Role of the Plexin Receptor and the Rho Family GTPase Regulators in Axon Guidance in the Embryonic Central Nervous System of Drosophila Melanogaster written by Hailan Hu and published by . This book was released on 2002 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Molecular Genetic Analysis of the Role of the Guanine Nucleotide Exchange Factor Trio During Axon Pathfinding in the Embryonic CNS of Drosophila Melanogaster written by David J. Forsthoefel and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: The Drosophila melanogaster embryo is an ideal system in which to study axon guidance, because of the relative simplicity of the nervous system and the evolutionary conservation of the molecules utilized during development. The Abelson cytoplasmic tyrosine kinase regulates actin cytoskeletal dynamics in Drosophila, mice, and humans. In Drosophila, Abl is expressed in the developing central and peripheral nervous systems (CNS and PNS). In a genetic screen for modifiers of the Abl mutant semilethality phenotype, we identified trio, a cytoplasmic guanine nucleotide exchange factor that is also expressed in the CNS and regulates actin dynamics through Rho GTPases. Mutations in Abl and trio interacted genetically, leading to dramatic disruption of axon pathways at the CNS midline. Building upon these initial observations, we analyzed interactions between Abl, trio, and the attractive Netrin receptor frazzled (fra)/Deleted-in-Colorectal-Cancer (DCC). In fra;Abl and fra;trio double mutants, few axons crossed the midline, similar to the phenotype in trio, Abl mutants. Furthermore, mutations in Abl and trio suppressed the inappropriate midline crossover phenotype in embryos expressing the chimeric Robo-Fra receptor, consistent with an in vivo role for these molecules as Fra effectors. Fra bound Abl and Trio in coimmunoprecipitation and GST pulldown experiments, and tyrosine phosphorylation of Fra and Trio was elevated in cultured cells overexpressing Abl. Mutations in enabled (ena), another Abl substrate, suppressed the loss-of-commissure phenotype in fra, Abl, and trio mutants, as well as the Robo-Fra receptor phenotype. Together, these results suggest that Abl and Trio are effectors for multiple attractive receptors at the CNS midline, and that Ena may function during both attractive and repulsive signaling. Finally, a functional analysis of the requirement for Trio's conserved domains has been initiated. In transgenic rescue and overexpression experiments, TrioGEF1 was required for axon guidance across the CNS midline, while TrioSH3 inhibited midline crossing. Coexpression experiments with the Robo-Fra receptor and assays in other tissues and cultured cells suggest that the conserved N-terminal domain, spectrin-like repeats, and GEF2 domain may modulate GEF1 signaling in specific contexts. Future experiments must elucidate the mechanistic details of cytoskeletal control by Trio and Fra.
Download or read book In Vivo Structure function Analysis of Drosophila Robo1 an Axon Guidance Receptor Critical for Midline Repulsive Signaling in the Embryonic Central Nervous System written by Haley Elizabeth Brown and published by . This book was released on 2018 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Molecular Genetic Analysis of Axon Guidance in Drosophila Melanogaster written by Huidy Shu and published by . This book was released on 2001 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Brain Development in Drosophila melanogaster written by Gerhard Martin Technau and published by Springer Science & Business Media. This book was released on 2009-01-08 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fruitfly Drosophila melanogaster is an ideal model system to study processes of the central nervous system This book provides an overview of some major facets of recent research on Drosophila brain development.
Download or read book Genetic Analysis of Axon Guidance in Drosophila Melanogaster written by Ashley Palani Wright and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transcriptional Regulation in the Embryonic Central Nervous System of Drosophila written by Robert Graham Franks and published by . This book was released on 1994 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Axon Growth and Guidance written by Dominique Bagnard and published by Springer Science & Business Media. This book was released on 2008-12-10 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book proposes an updated view of the current knowledge of the molecular and cellular mechanisms ensuring axon growth and guidance. The introductory chapter will remind the readers of all the features of a growth cone and the mechanisms controlling its growth. From there, one enters a fabulous journey with a growth cone, a Tom Thumb story filled with molecular encounters and complex interactions leading to one of the most fantastic developmental achievements: the nervous system wiring.
Download or read book The Regulation of Commissureless in the Embryonic CNS of Drosophila Melanogaster written by Casey C. Jowdy and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: During development the precise wiring of the nervous system is dependent on the correct repertoire of axon guidance molecules being expressed at the right time and place. In the CNS of D. melanogaster, Comm and Robo play important roles in regulating axons at the midline. To date much has been studied about how Comm regulates Robo, but little is known about how Comm is regulated in the CNS. Comm is dynamically expressed in an off, on, and off again fashion in contralaterally projecting axons and is not expressed in ipsilateral projecting axons. Our hypothesis is the dynamic spatial and temporal regulation of Comm is at the transcriptional level.
Download or read book Genetic Analysis of Signaling Pathways Involved in Drosophila Embryonic Axon Guidance written by Jessica Elizabeth Palmer and published by . This book was released on 2003 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Molecular and Genetic Analysis of Neuromuscular Connectivity and Synaptic Growth in Drosophila Melanogaster written by Hong Iris Wan and published by . This book was released on 2000 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Genetic and Molecular Analysis of Neuromuscular Connectivity in Drosophila Melanogaster written by Douglas McIntosh Fambrough and published by . This book was released on 1996 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis of the Roles of Drosophila Netrin Receptors Frazzled and Unc5 in Axon Guidance written by Theresa Wei-Yuan Ho and published by . This book was released on 2002 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Genetic Analysis of Dlar in Axon Guidance and Synaptic Development in Drosophila Melanogaster written by Nancy Kaufmann and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Development of Drosophila Melanogaster written by Michael Bate and published by . This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fruit fly Drosophila melanogaster offers the most powerful means of studying embryonic development in eukaryotes. New information from many different organ systems has accumulated rapidly in the past decade. This monograph, written by the most distinguished workers in the field, is the most authoritative and comprehensive synthesis of Drosophila developmental biology available and emphasizes the insights gained by molecular and genetic analysis. In two volumes, it is a lavishly illustrated, elegantly designed reference work illustrating principles of genetic regulation of embryogenesis that may apply to other eukaryotes.
