scholarly journals Notochord vacuoles are lysosome-related organelles that function in axis and spine morphogenesis

2013 ◽  
Vol 200 (5) ◽  
pp. 667-679 ◽  
Author(s):  
Kathryn Ellis ◽  
Jennifer Bagwell ◽  
Michel Bagnat
Keyword(s):  
Embryonic Development ◽  
Early Development ◽  
Molecular Mechanisms ◽  
Body Axis ◽  
Endosomal Trafficking ◽  
Vertebrate Development ◽  
Axis Elongation ◽  
Lysosome Related Organelles ◽  
Spine Morphogenesis

The notochord plays critical structural and signaling roles during vertebrate development. At the center of the vertebrate notochord is a large fluid-filled organelle, the notochord vacuole. Although these highly conserved intracellular structures have been described for decades, little is known about the molecular mechanisms involved in their biogenesis and maintenance. Here we show that zebrafish notochord vacuoles are specialized lysosome-related organelles whose formation and maintenance requires late endosomal trafficking regulated by the vacuole-specific Rab32a and H+-ATPase–dependent acidification. We establish that notochord vacuoles are required for body axis elongation during embryonic development and identify a novel role in spine morphogenesis. Thus, the vertebrate notochord plays important structural roles beyond early development.

scholarly journals The Reissner Fiber is Highly Dynamic in vivo and Controls Morphogenesis of the Spine

2019 ◽  
Author(s):  
Benjamin Troutwine ◽  
Paul Gontarz ◽  
Ryoko Minowa ◽  
Adrian Monstad-Rios ◽  
Mia J. Konjikusic ◽  
...  
Keyword(s):  
Nervous System ◽  
Embryonic Development ◽  
Dynamic Properties ◽  
Central Canal ◽  
The Body ◽  
Body Axis ◽  
List Type ◽  
The Central Nervous System ◽  
Spine Morphogenesis

SummarySpine morphogenesis requires the integration of multiple musculoskeletal tissues with the nervous system. Cerebrospinal fluid (CSF) physiology is important for development and homeostasis of the central nervous system and its disruption has been linked to scoliosis in zebrafish [1, 2]. Suspended in the CSF is an enigmatic glycoprotein thread called the Reissner fiber, which is secreted from the subcomissural organ (SCO) in the brain and extends caudally through the central canal to where it terminates at the base of the spinal cord. In zebrafish, scospondin null mutants are unable to assemble the Reissner fiber and fail to extend a straight body axis during embryonic development [3]. Here, we describe zebrafish hypomorphic missense alleles, which assemble the Reissner fiber and straighten the body axis during early embryonic development, yet progressively lose the fiber, concomitant with the emergence of body curvature, alterations in neuronal gene expression, and scoliosis in adults. Using an endogenously tagged scospondin-GFP zebrafish knock-in line, we directly visualized Reissner fiber dynamics during the normal development and during the progression of scoliosis, and demonstrate that the Reissner fiber is critical for the morphogenesis of the spine. Our study establishes a framework for future investigations of mechanistic roles of the Reissner fiber including its dynamic properties, molecular interactions, and how these processes are involved in the regulation of spine morphogenesis and scoliosis.HighlightsHypomorphic mutations in zebrafish scospondin result in progressive scoliosisThe disassembly of the Reissner fiber in scospondin hypomorphic mutants results in the strong upregulation of neuronal receptors and synaptic transport componentsAn endogenous fluorescent knock-in allele of scospondin reveals dynamic properties of the Reissner fiber during zebrafish developmentLoss of the Reissner fiber during larval development is a common feature of zebrafish scoliosis models

Live Confocal Analysis of Fertilization and Early Development

2001 ◽  
Vol 7 (S2) ◽  
pp. 1012-1013
Author(s):  
Uyen Tram ◽  
William Sullivan
Keyword(s):  
Drosophila Melanogaster ◽  
Embryonic Development ◽  
Real Time ◽  
Early Development ◽  
Fluorescent Probes ◽  
Primary Defect ◽  
Fluorescent Analysis ◽  
Dynamic Event ◽  
Enormous Amount ◽  
Fluorescent Studies

Embryonic development is a dynamic event and is best studied in live animals in real time. Much of our knowledge of the early events of embryogenesis, however, comes from immunofluourescent analysis of fixed embryos. While these studies provide an enormous amount of information about the organization of different structures during development, they can give only a static glimpse of a very dynamic event. More recently real-time fluorescent studies of living embryos have become much more routine and have given new insights to how different structures and organelles (chromosomes, centrosomes, cytoskeleton, etc.) are coordinately regulated. This is in large part due to the development of commercially available fluorescent probes, GFP technology, and newly developed sensitive fluorescent microscopes. For example, live confocal fluorescent analysis proved essential in determining the primary defect in mutations that disrupt early nuclear divisions in Drosophila melanogaster. For organisms in which GPF transgenics is not available, fluorescent probes that label DNA, microtubules, and actin are available for microinjection.

scholarly journals Revising Endosomal Trafficking under Insulin Receptor Activation

2021 ◽  
Vol 22 (13) ◽  
pp. 6978
Author(s):  
Maria J. Iraburu ◽  
Tommy Garner ◽  
Cristina Montiel-Duarte
Keyword(s):  
Plasma Membrane ◽  
Tyrosine Kinase ◽  
Insulin Receptor ◽  
Molecular Mechanisms ◽  
Receptor Activation ◽  
Small Gtpases ◽  
Early Endosome ◽  
Tyrosine Kinase Receptors ◽  
Endosomal Trafficking ◽  
Cell Functions

The endocytosis of ligand-bound receptors and their eventual recycling to the plasma membrane (PM) are processes that have an influence on signalling activity and therefore on many cell functions, including migration and proliferation. Like other tyrosine kinase receptors (TKR), the insulin receptor (INSR) has been shown to be endocytosed by clathrin-dependent and -independent mechanisms. Once at the early endosome (EE), the sorting of the receptor, either to the late endosome (LE) for degradation or back to the PM through slow or fast recycling pathways, will determine the intensity and duration of insulin effects. Both the endocytic and the endosomic pathways are regulated by many proteins, the Arf and Rab families of small GTPases being some of the most relevant. Here, we argue for a specific role for the slow recycling route, whilst we review the main molecular mechanisms involved in INSR endocytosis, sorting and recycling, as well as their possible role in cell functions.

scholarly journals Unfolded protein response triggers differential apoptotic mechanisms in ovaries and early embryos exposed to maternal type 1 diabetes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aslı Okan ◽  
Necdet Demir ◽  
Berna Sozen
Keyword(s):  
Embryonic Development ◽  
Er Stress ◽  
Unfolded Protein Response ◽  
Molecular Mechanisms ◽  
Early Embryonic Development ◽  
Unfolded Protein ◽  
Caspase 12 ◽  
Early Embryos ◽  
Protein Response

AbstractDiabetes mellitus (DM) has profound effects on the female mammalian reproductive system, and early embryonic development, reducing female reproductive outcomes and inducing developmental programming in utero. However, the underlying cellular and molecular mechanisms remain poorly defined. Accumulating evidence implicates endoplasmic reticulum (ER)-stress with maternal DM associated pathophysiology. Yet the direct pathologies and causal events leading to ovarian dysfunction and altered early embryonic development have not been determined. Here, using an in vivo mouse model of Type 1 DM and in vitro hyperglycaemia-exposure, we demonstrate the activation of ER-stress within adult ovarian tissue and pre-implantation embryos. In diabetic ovaries, we show that the unfolded protein response (UPR) triggers an apoptotic cascade by the co-activation of Caspase 12 and Cleaved Caspase 3 transducers. Whereas DM-exposed early embryos display differential ER-associated responses; by activating Chop in within embryonic precursors and Caspase 12 within placental precursors. Our results offer new insights for understanding the pathological effects of DM on mammalian ovarian function and early embryo development, providing new evidence of its mechanistic link with ER-stress in mice.

scholarly journals Early development of apoplastic barriers and molecular mechanisms in juvenile maize roots in response to La2O3 nanoparticles

2019 ◽  
Vol 653 ◽  
pp. 675-683 ◽  
Author(s):  
Le Yue ◽  
Feiran Chen ◽  
Kaiqiang Yu ◽  
Zhenggao Xiao ◽  
Xiaoyu Yu ◽  
...  
Keyword(s):  
Early Development ◽  
Molecular Mechanisms ◽  
Maize Roots ◽  
Apoplastic Barriers

scholarly journals Melatonin enhances porcine embryo development via the Nrf2/ARE signaling pathway

2019 ◽  
Vol 63 (3) ◽  
pp. 175-185 ◽  
Author(s):  
Eui Hyun Kim ◽  
Geon A Kim ◽  
Anukul Taweechaipaisankul ◽  
Seok Hee Lee ◽  
Muhammad Qasim ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Signaling Pathway ◽  
Molecular Mechanisms ◽  
Antioxidant Properties ◽  
Specific Inhibitor ◽  
Treated Group ◽  
Related Factor ◽  
Porcine Embryo ◽  
Responsive Element

Oxidative stress (OS) is a major problem during in vitro culture of embryos. Numerous studies have shown that melatonin, which is known to have antioxidant properties, prevents the occurrence of OS in embryos. However, the molecular mechanisms by which melatonin prevents OS in embryos are still unclear. The present study suggests a possible involvement of the nuclear factor erythroid 2-related factor 2/antioxidant-responsive element (Nrf2/ARE) signaling pathway, which is one of the prominent signals for OS prevention through Nrf2 activation, connecting melatonin, OS prevention and porcine embryonic development. The aim of this study was to investigate the effects of melatonin (10−7 M) on porcine embryonic development via the Nrf2/ARE signaling pathway; brusatol (50 nM; Nrf2 specific inhibitor) was used to validate the mechanism. Treatment of porcine embryo with melatonin significantly increased formation rates of blastocysts and their total cell numbers and also upregulated the expression of Nrf2/ARE signaling and apoptosis-related genes (MT2, NRF2, UCHL, HO-1, SOD1 and BCL-2). Furthermore, the expression of proteins (NRF2 and MT2) was also upregulated in the melatonin-treated group. Concomitantly, brusatol significantly inhibited these effects, upregulating the expression of KEAP1 and BAX, including the expression level of KEAP1 protein. These results provide evidences that melatonin prevents OS through Nrf2/ARE signaling pathway in porcine in vitro fertilization -derived embryos.

scholarly journals CTCF looping is established during gastrulation in medaka embryos

2018 ◽  
Author(s):  
Ryohei Nakamura ◽  
Yuichi Motai ◽  
Masahiko Kumagai ◽  
Haruyo Nishiyama ◽  
Neva C. Durand ◽  
...  
Keyword(s):  
Gene Regulation ◽  
Embryonic Development ◽  
Protein Binding ◽  
Early Development ◽  
Great Increase ◽  
Critical Role ◽  
Early Embryogenesis ◽  
Genome Architecture ◽  
Time Points ◽  
Genome Wide

Abstract:Genome architecture plays a critical role in gene regulation, but how the structures seen in mature cells emerge during embryonic development remains poorly understood. Here, we study early development in medaka (the Japanese killifish, Oryzias latipes) at 12 time points before, during, and after gastrulation which is the most dramatic event in early embryogenesis, and characterize transcription, protein binding, and genome architecture. We find that gastrulation is most associated with drastic changes in genome architecture, including the formation of the first loops between sites bound by the insulator protein CTCF and great increase in the size of contact domains. However, the position of CTCF is fixed throughout medaka embryogenesis. Interestingly, genome-wide transcription precedes the emergence of mature domains and CTCF-CTCF loops.

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