Download or read book Genes and Mechanisms Underlying the Development of Dendrites in the Central Nervous System of the Drosophila Embryo written by Barbara Chwalla and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Genetic Mechanisms Regulating the Spatiotemporal Modulation of Proliferation Rate and Mode in Neural Progenitors and Daughter Cells during Embryonic CNS Development written by Behzad Yaghmaeian Salmani and published by Linköping University Electronic Press. This book was released on 2018-05-09 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: The central nervous system (CNS) is a hallmark feature of animals with a bilateral symmetry: bilateria and can be sub-divided into the brain and nerve cord. One of the prominent properties of the CNS across bilateria is the discernible expansion of its anterior part (brain) compared with the posterior one (nerve cord). This evolutionarily conserved feature could be attributed to four major developmental agencies: First, the existence of more anterior progenitors. Second, anterior progenitors are more proliferative. Third, anterior daughter cells, generated by the progenitors, are more proliferative. Forth, fewer cells are removed by programmed cell death (PCD) anteriorly. My thesis has addressed these issues, and uncovered both biological principles and genetic regulatory networks that promote these A-P differences. I have used the Drosophila and mouse embryonic CNSs as model systems. Regarding the 1st issue, while the brain indeed contains more progenitors, my studies demonstrate that this only partly explains the anterior expansion. Indeed, with regard to the 2nd issue, my studies, on both the Drosophila and mouse CNS, demonstrate that anterior progenitors divide more extensively. Concerning the 3rd issue, in Drosophila we identified a gradient of daughter proliferation along the AP axis of the developing CNS with brain daughter cells being more proliferative. Specifically, in the brain, progenitors divide to generate a series of daughter cells that divide once (Type I), to generate two neurons or glia. In contrast, in the nerve cord, progenitors switch during later stages, from first generating dividing daughters to subsequently generating daughters that directly differentiate (Type 0). Hence, nerve cord progenitors undergo a programmed Type I->0 proliferation switch. In the Drosophila posterior CNS, this switch occurs earlier and is more prevalent, contributing to the generation of smaller lineages in the posterior regions. Similar to Drosophila, in the mouse brain we also found that progenitor and daughter cell proliferation was elevated and extended into later developmental stages, when compared to the spinal cord. DNA-labeling experiments revealed faster cycling cells in the brain when compared to the nerve cord, in both Drosophila and mouse. In both Drosophila and mouse, we found that the suppression of progenitor and daughter proliferation in the nerve cord is controlled by the Hox homeotic gene family. Hence, the absence of Hox gene expression in the brain provides a logical explanation for the extended progenitor proliferation and lack of Type I->0 switch. The repression of Hox genes in the brain is mediated by the histonemodifying Polycomb Group complex (PcG), which thereby is responsible for the anterior expansion. With respect to the 4th issue, we found no effect of PCD on anterior expansion in Drosophila, while this cannot be asserted for the mouse embryonic neurodevelopment as there are no genetic tools to abolish PCD effectively in mammals. Taken together, the studies presented in this thesis identified global and evolutionarily-conserved genetic programs that promote anterior CNS expansion, and pave the way for understanding the evolution of size along the anterior-posterior CNS axis.

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 Building Brains written by David J. Price and published by John Wiley & Sons. This book was released on 2011-07-22 with total page 349 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of a brain from its simple beginnings in the embryo to the extraordinarily complex fully-functional adult structure is a truly remarkable process. Understanding how it occurs remains a formidable challenge despite enormous advances over the last century and current intense world-wide scientific research. A greater knowledge of how nervous systems construct themselves will bring huge benefits for human health and future technologies. Unravelling the mechanisms that lead to the development of healthy brains should help scientists tackle currently incurable diseases of the nervous system such as autism, epilepsy and schizophrenia (to name but a few), discover more about the processes that cause the uncontrolled growth associated with cancer and develop possible treatments. Building Brains provides a highly visual and readily accessible introduction to the main events that occur during neural development and the mechanisms by which they occur. Aimed at undergraduate students and postgraduates new to the field, who may not have a background in neuroscience and/or molecular genetics, it explains how cells in the early embryo first become neural, how their proliferation is controlled, what regulates the types of neural cells they become, how neurons connect to each other, how these connections are later refined under the influence of neural activity including that arising from experience, and why some neurons normally die. Key Features: A concise illustrated guide focusing on the core elements of current understanding of neural development, emphasising common principles underlying developmental mechanisms and supplemented by suggestions for further reading. Text boxes throughout provide further detail on selected major advances, issues of particular uncertainty or controversy and examples of human diseases that result from abnormal development. A balanced mammalian/non-mammalian perspective, drawing on examples from model organisms including the fruit fly, nematode worm, frog, zebrafish, chick, mouse, ferret, cat, monkey and human, and emphasising mechanisms that are conserved across species. Introduces the methods for studying neural development including genetics, transgenic technologies, advanced microscopy and computational modeling, allowing the reader to understand the main evidence underlying research advances. Student-friendly, full colour artwork reinforces important concepts; an extensive glossary and definitions in page margins help readers from different backgrounds; chapter summaries stress important points and aid revision. Associated Website includes a complete set of figures from the textbook.

Download or read book Molecular Biology of the Cell written by and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Exploring Developmental Mechanisms and Function of Drosophila Motoneuron Dendrites with Targeted Genetic Manipulation of Dscam written by Katie Marie Hutchinson and published by . This book was released on 2013 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: Specific dendritic morphologies are a hallmark of neuronal identity, circuit assembly, and behaviorally relevant function. Despite the importance of dendrites in brain health and disease, the functional consequences of dendritic shape remain largely unknown. This dissertation addresses two fundamental and interrelated aspects of dendrite neurobiology. First, by utilizing the genetic power of Drosophila melanogaster, these studies assess the developmental mechanisms underlying single neuron morphology, and subsequently investigate the functional and behavioral consequences resulting from developmental irregularity. Significant insights into the molecular mechanisms that contribute to dendrite development come from studies of Down syndrome cell adhesion molecule (Dscam). While these findings have been garnered primarily from sensory neurons whose arbors innervate a two-dimensional plane, it is likely that the principles apply in three-dimensional central neurons that provide the structural substrate for synaptic input and neural circuit formation. As such, this dissertation supports the hypothesis that neuron type impacts the realization of Dscam function. In fact, in Drosophila motoneurons, Dscam serves a previously unknown cell-autonomous function in dendrite growth. Dscam manipulations produced a range of dendritic phenotypes with alteration in branch number and length. Subsequent experiments exploited the dendritic alterations produced by Dscam manipulations in order to correlate dendritic structure with the suggested function of these neurons. These data indicate that basic motoneuron function and behavior are maintained even in the absence of all adult dendrites within the same neuron. By contrast, dendrites are required for adjusting motoneuron responses to specific challenging behavioral requirements. Here, I establish a direct link between dendritic structure and neuronal function at the level of the single cell, thus defining the structural substrates necessary for conferring various aspects of functional motor output. Taken together, information gathered from these studies can inform the quest in deciphering how complex cell morphologies and networks form and are precisely linked to their function.

Download or read book Neuromuscular Junctions in Drosophila written by and published by Academic Press. This book was released on 1999-04-29 with total page 317 pages. Available in PDF, EPUB and Kindle. Book excerpt: Neuromuscular Junctions in Drosophila gathers the main contributions that research using the fruit fly Drosophila melanogaster has made in the area of synapse development, synapse physiology, and excitability of muscles and nerve cells. The chapters in this book represent a synthesis of major advances in our understanding of neuronal development and synaptic physiology, which have been obtained using the above approach.This book is directed to the general neuroscience audience: researchers, instructors, graduate students, and advanced undergraduates who are interested in the mechanisms of synapse development and physiology. However, the book will also be a valuable resource for those that use the fruit fly as a model system in their laboratories.Key Features* Synthesizes the genetic approaches used to study synaptic development and function at the neuromuscular junction, using flies as a model system* Covers major recent advances in muscle development, pathfinding, synapse maturation and plasticity, exo- and endocytosis, and ion channel function* Written in clear language that is easily understandable to readers not already familiar with fruit fly research* Includes numerous diagrams and extensive reference lists

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 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 Genetic Mechanisms Regulating the Spatiotemporal Modulation of Proliferation Rate and Mode in Neural Progenitors and Daughter Cells During Embryonic CNS Development written by Behzad Yaghmaeian Salmani and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The central nervous system (CNS) is a hallmark feature of animals with a bilateral symmetry: bilateria and can be sub-divided into the brain and nerve cord. One of the prominent properties of the CNS across bilateria is the discernible expansion of its anterior part (brain) compared with the posterior one (nerve cord). This evolutionarily conserved feature could be attributed to four major developmental agencies: First, the existence of more anterior progenitors. Second, anterior progenitors are more proliferative. Third, anterior daughter cells, generated by the progenitors, are more proliferative. Forth, fewer cells are removed by programmed cell death (PCD) anteriorly. My thesis has addressed these issues, and uncovered both biological principles and genetic regulatory networks that promote these A-P differences. I have used the Drosophila and mouse embryonic CNSs as model systems. Regarding the 1st issue, while the brain indeed contains more progenitors, my studies demonstrate that this only partly explains the anterior expansion. Indeed, with regard to the 2nd issue, my studies, on both the Drosophila and mouse CNS, demonstrate that anterior progenitors divide more extensively. Concerning the 3rd issue, in Drosophila we identified a gradient of daughter proliferation along the AP axis of the developing CNS with brain daughter cells being more proliferative. Specifically, in the brain, progenitors divide to generate a series of daughter cells that divide once (Type I), to generate two neurons or glia. In contrast, in the nerve cord, progenitors switch during later stages, from first generating dividing daughters to subsequently generating daughters that directly differentiate (Type 0). Hence, nerve cord progenitors undergo a programmed Type I->0 proliferation switch. In the Drosophila posterior CNS, this switch occurs earlier and is more prevalent, contributing to the generation of smaller lineages in the posterior regions. Similar to Drosophila , in the mouse brain we also found that progenitor and daughter cell proliferation was elevated and extended into later developmental stages, when compared to the spinal cord. DNA-labeling experiments revealed faster cycling cells in the brain when compared to the nerve cord, in both Drosophila and mouse. In both Drosophila and mouse, we found that the suppression of progenitor and daughter proliferation in the nerve cord is controlled by the Hox homeotic gene family. Hence, the absence of Hox gene expression in the brain provides a logical explanation for the extended progenitor proliferation and lack of Type I->0 switch. The repression of Hox genes in the brain is mediated by the histonemodifying Polycomb Group complex (PcG), which thereby is responsible for the anterior expansion. With respect to the 4th issue, we found no effect of PCD on anterior expansion in Drosophila , while this cannot be asserted for the mouse embryonic neurodevelopment as there are no genetic tools to abolish PCD effectively in mammals. Taken together, the studies presented in this thesis identified global and evolutionarily-conserved genetic programs that promote anterior CNS expansion, and pave the way for understanding the evolution of size along the anterior-posterior CNS axis.

Download or read book Systems Level Investigation of Transcriptional and Post transcriptional Mechanisms Directing Class specific Dendrite Morphogenesis written by Srividya Chandramouli Iyer and published by . This book was released on 2013 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dendrites - neuronal structures that are primarily designed for information input, are one of nature's remarkable architectural feats and the elaborate and manifold growth patterns displayed by dendritic arbors raise important developmental questions. The particular shapes of dendrites are not only hallmarks of neuronal identity but are also crucial in neuronal function and circuit assembly as they influence the range of inputs received by a neuron and thereby, the processing and integration of electrical signals. Therefore, insights into mechanisms underlying the developmental origins of arbor shape will shape our understanding of how the nervous system functions and take us closer to identifying the underlying causes of several neurological and neurodevelopmental disorders. During the past two decades, studies in Drosophila melanogaster have identified mechanisms of dendrite morphogenesis with great potential for broad applicability to vertebrate species. In particular, owing to their stereotyped and class-specific dendrite branching patterns, the Drosophila dendritic arborization (da) sensory neurons have emerged as an excellent model system to investigate the cellular and molecular mechanisms that regulate the acquisition of distinct dendritic architectures and receptive field specification. Indeed, studies to date, have demonstrated that genetic signatures underlying class-specific dendrite morphogenesis, are regulated by complex molecular programs acting at both the transcriptional and post-transcriptional levels. Previous studies on transcription control of neuronal shape have characterized several transcription factors that function to specify and control dendritic growth/branching and cytoskeletal rearrangements. For example, members of the Cut/Cux1/Cux2 family of homeodomain transcription factors have been shown to be multi-level regulators of synaptogenesis and dendritic spine morphology in the brain cortex. While the significance of Cut in generating neuronal diversity is recognized, the machinery underlying Cut-mediated regulation of dendritic elaboration in da neurons remains largely unknown. In this study, we show evidence for dynamic links between transcriptional cues and two important conserved cellular processes that allow translation into changes in neuronal architecture: (1) Regulation of the actin and microtubule cytoskeleton and (2) The intracellular membrane transport system. Here, we implicate the Rho-GEF Trio, an evolutionarily conserved multi-functional domain protein, as an important downstream effector in Cut mediated regulation of filopodia formation, via interactions with Rac1 and Rho1. In addition, we demonstrate gene expression cascades initiated by Cut, via CrebA, that regulate a specific sub-cellular function, COPII transport, as one important means of mediating large-scale changes in cellular morphology. A second crucial level of regulation lies at the post-transcriptional level in which miRNAs have emerged as very important modulation of gene expression across numerous cellular contexts, such as embryonic development, stem cell division and cancer to name a few. Several recent studies in Drosophila have implicated individual miRNAs, as well as, RISC components, essential for miRNA biogenesis, in various aspects of neuronal development including, local translation at synapses to regulate synaptic strength, and growth of dendritic spines. Despite these advances, the precise role of miRNAs in neuronal morphogenesis and, in particular, dendrite development remains largely unknown. Here, we have conducted the first miRnome level investigation into the role of miRNA mediated regulation of dendrite morphogenesis using a combination of functional genomics, bioinformatics and rigorous phenotypic validation. Whole genome miRNA profiling experiments in distinct subclasses of da neurons reveal a largely differential pattern of expression for miRNAs in neurons of varying dendritic complexity. In addition, via a systematic large-scale gain-of-function screen, we have uncovered miRNAs with previously unknown functions in forming dendrite architecture. Furthermore, we provide the first evidence for the role of K box miRNAs in directing class-specific dendrite development and demonstrate that they function by targeting genes that repress dendrite complexity.

Download or read book A Single Neuron Model to Study the Mechanisms and Functions of Dendritic Development written by Fernando Jaime Vonhoff and published by . This book was released on 2012 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dendrites are the structures of a neuron specialized to receive input signals and to provide the substrate for the formation of synaptic contacts with other cells. The goal of this work is to study the activity-dependent mechanisms underlying dendritic growth in a single-cell model. For this, the individually identifiable adult motoneuron, MN5, in Drosophila melanogaster was used. This dissertation presents the following results. First, the natural variability of morphological parameters of the MN5 dendritic tree in control flies is not larger than 15%, making MN5 a suitable model for quantitative morphological analysis. Second, three-dimensional topological analyses reveals that different parts of the MN5 dendritic tree innervate spatially separated areas (termed "isoneuronal tiling"). Third, genetic manipulation of the MN5 excitability reveals that both increased and decreased activity lead to dendritic overgrowth; whereas decreased excitability promoted branch elongation, increased excitability enhanced dendritic branching. Next, testing the activity-regulated transcription factor AP-1 for its role in MN5 dendritic development reveals that neural activity enhanced AP-1 transcriptional activity, and that AP-1 expression lead to opposite dendrite fates depending on its expression timing during development. Whereas overexpression of AP-1 at early stages results in loss of dendrites, AP-1 overexpression after the expression of acetylcholine receptors and the formation of all primary dendrites in MN5 causes overgrowth. Fourth, MN5 has been used to examine dendritic development resulting from the expression of the human gene MeCP2, a transcriptional regulator involved in the neurodevelopmental disease Rett syndrome. Targeted expression of full-length human MeCP2 in MN5 causes impaired dendritic growth, showing for the first time the cellular consequences of MeCP2 expression in Drosophila neurons. This dendritic phenotype requires the methyl-binding domain of MeCP2 and the chromatin remodeling protein Osa. In summary, this work has fully established MN5 as a single-neuron model to study mechanisms underlying dendrite development, maintenance and degeneration, and to test the behavioral consequences resulting from dendritic growth misregulation. Furthermore, this thesis provides quantitative description of isoneuronal tiling of a central neuron, offers novel insight into activity- and AP-1 dependent developmental plasticity, and finally, it establishes Drosophila MN5 as a model to study some specific aspects of human diseases.

Download or read book Mechanisms of Depolarization Induced Dendritic Growth of Drosophila Motor Neurons written by Cortnie Lauren Cherry and published by . This book was released on 2006 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt: MECHANISMS OF DEPOLARIZATION INDUCED DENDRITIC GROWTH OF DROSOPHILA MOTOR NEURONS Cortnie Lauren Cherry The University of Arizona, 2006 Director: Richard B. Levine The study of the cellular mechanisms underlying dendritic growth contributes to our understanding of nervous system development, function and disease. Electrical activity is a fundamental property of neurons, and this property is utilized to influence the mechanisms involved in dendrite formation and maturation. Here we employ the Drosophila transgenic system to quantify dendritic growth of identified motor neurons using both in vitro and in vivo techniques. Two novel techniques are introduced: one a system to visualize and measure dendritic outgrowth in cultured neurons using reporter proteins, and the other using 3D reconstruction to measure the arborization of identified motor neurons in vivo. Both transgenic manipulation of K+ channel function and depolarizing concentrations of K+ in the culture medium result in an acceleration of dendritic outgrowth. Depolarization induced outgrowth is dependent on Plectreurys Toxin (PLTX)-sensitive voltage-gated calcium current and protein synthesis in cultured motor neurons. Depolarization leads to direct induction of fos, a protein that heterodimerizes with jun to make the functional transcription factor, AP-1. Fos, but not jun, is necessary for basal levels of dendritic growth, while both are necessary for depolarization induced outgrowth. Over-expression of AP-1 in control cells is sufficient to cause dendritic outgrowth. The transcription factor Adf-1 is also necessary for basal and depolarization induced growth, but unlike AP-1 is not sufficient to cause outgrowth when over-expressed. Another transcription factor CREB, on the other hand, is not necessary for basal levels of dendritic growth, but is necessary for depolarization induced dendritic growth. Over-expression of CREB, like Adf-1, is not sufficient to cause dendritic outgrowth. These findings present exciting new techniques for the study of the field of dendritic regulation and contribute to our understanding of the cellular mechanisms underlying dendritic growth.

Download or read book The Embryonic Development of Drosophila melanogaster written by Jose A. Campos-Ortega and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt: " . . . but our knowledge is so weak that no philosoph er will ever be able to completely explore the nature of even a fly . . . " * Thornas Aquinas "In Syrnbolurn Apostolorum" 079 RSV p/96 This is a monograph on embryogenesis of the fruit fly Drosophi la melanogaster conceived as a reference book on morphology of embryonie development. A monograph of this extent and con tent is not yet available in the literature of Drosophila embryolo gy, and we believe that there is areal need for it. Thanks to the progress achieved during the last ten years in the fields of devel opmental and molecular genetics, work on Drosophila develop ment has considerably expanded creating an even greater need for the information that we present here. Our own interest for wildtype embryonie development arose several years ago, when we began to study the development of mutants. While those studies were going on we repeatedly had occasion to state in sufficiencies in the existing literature about the embryology of the wildtype, so that we undertook investigating many of these problems by ourselves. Convinced that several of our colleagues will have encountered similar difficulties we decided to publish the present monograph. Although not expressely recorded, Thomas Aquinas probably referred to the domestic fly and not to the fruit fly. Irrespective of which fly he meant, however, we know that Thomas was right in any case.

Download or read book Molecular Genetic Characterization of Jing During Drosophila Embryonic Central Nervous System and Tracheal System Development written by Yalda Sedaghat and published by . This book was released on 2005 with total page 582 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Generation of Cellular Pattern and Fate in the Drosophila Embryonic Central Nervous System written by James Benjamin Skeath and published by . This book was released on 1993 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Extracellular Regulation and Scaling of Sensory Dendrites and Tissue specificmutagenesis Tools in Drosophila written by Amy Rosetta Poe and published by . This book was released on 2018 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: The diverse and intricate dendritic branching patterns of neurons determine their ability to collect synaptic and sensory information. Defects in the formation and maintenance of dendritic patterns underlie many neurological disorders. Therefore, it is essential to understand how neurons develop dendritic arbors with the proper branching patterns in a complex nervous system. During animal development, many neurons establish dendritic territories early and then expand dendritic arbors proportionally to the body size in a process called scaling. Among those neurons, some are capable of filling empty space in the receptive field with highly dynamic dendritic branches. Dendritic scaling and space filling require an integration of intrinsic mechanisms, extracellular signals, and information about the organism's nutritional environment. To understand the multi-level mechanisms controlling dendrite branching, my research used Drosophila class IV dendritic arborization (da) neurons. For the first part of my thesis, I identified the epidermal cell-derived heparan sulfate proteoglycans (HSPGs), Dally and Sdc, as permissive signals for the space filling of class IV da neuron. We demonstrated that HSPGs stabilize dendrites by promoting microtubule stabilization. These data uncover novel pathways through which extracellular signals regulate dendritic space-filling in sensory neurons. In the second part of my thesis, I examined the relationship between sensory neuron and larval body growth under normal and nutrient stress conditions. My research revealed distinct cellular responses of sensory neurons and epidermal cells to nutrient restriction, with sensory dendrites growing preferentially under nutrient stress. Interestingly, autophagy and the expression of the transcription factor FoxO is suppressed in sensory neurons, making neurons insensitive to nutrient restriction. These experiments reveal distinctive molecular mechanisms regulating neuron/non-neural cell growth. Finally, we developed and optimized a tissue-specific gene loss-of-function (LOF) strategy using the CRISPR/Cas9 system. This system allowed us to generate efficient tissue-specific gene knockout and to analyze redundantly acting genes in neural development. Using this strategy, we discovered the redundant and perdurant functions of SNARE components in dendrite morphogenesis. Together, my research reveals novel mechanisms in which extracellular signals, the nutritional environment, and redundantly acting genes regulate dendrite branching pattern formation.