scholarly journals Live Imaging of Cell Motility and Actin Cytoskeleton of Individual Neurons and Neural Crest Cells in Zebrafish Embryos

10.3791/1726 ◽  
2010 ◽  
Author(s):  
Erica Andersen ◽  
Namrata Asuri ◽  
Matthew Clay ◽  
Mary Halloran
Keyword(s):  
Actin Cytoskeleton ◽  
Neural Crest ◽  
Cell Motility ◽  
Neural Crest Cells ◽  
Live Imaging ◽  
Zebrafish Embryos

scholarly journals Vitamin E is Necessary to Protect Neural Crest Cells in Developing Zebrafish Embryos

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1209-1209
Author(s):  
Brian Head ◽  
Jane La Du ◽  
Robyn Tanguay ◽  
Chrissa Kioussi ◽  
Maret Traber
Keyword(s):  
Nervous System ◽  
Vitamin E ◽  
Neural Crest ◽  
System Development ◽  
Neural Crest Cells ◽  
Nervous System Development ◽  
Neural Plate ◽  
Zebrafish Embryos ◽  
Normal Brain ◽  
Collagen Formation

Abstract Objectives Vitamin E (VitE) deficiency causes vertebrate embryonic lethality. The alpha-tocopherol transfer protein (Ttpa) likely regulates VitE distribution in the early zebrafish embryo because Ttpa knockdown causes impaired nervous system development and embryonic death by 15–18 hours post-fertilization (hpf). We propose that VitE is necessary for normal brain and peripheral nervous system development. Methods Zebrafish embryos are obtained from adults fed either VitE sufficient (E+) or deficient (E–) diets for at least 80 days. Embryos at 12 and 24 hpf are subjected to RNA whole mount in situ hybridization (WISH). RNA is also collected from embryos at 12, 18 and 24 hpf for RT-qPCR of specific targets. Results At 12 hpf, the midbrain-hindbrain boundary and otic placodes are malformed in E– embryos, as shown by Pax2a expression. Similarly, Sox10 expression shows that E– embryos lack clear neural plate borders. Nonetheless, in 12 hpf E + and E− embryos Ttpa is localized similarly throughout the nervous system. Pax2a expression initiates collagen formation in the developing notochord. Collagen genes, col2a1a and col9a2, expression patterns showed abnormal notochord structures in 24 hpf E– embryos. At 24 hpf in E + embryos, Sox10 expressing-neural crest cells are localized both in the central nervous system and dorsal root ganglia (DRG), while the Sox10 signal is diminished in E– embryos in both the DRG and early enteric nervous system. At 24 hpf, Ttpa expression outlines the brain ventricle borders; critically E– embryos show reduced Ttpa signal and impaired ventricle closing. Gene expression by qPCR will be used to confirm these results. Conclusions This VitE deficient embryo model suggests that the carefully programmed development of the nervous system is distorted due to lack of adequate VitE. Thus, Ttpa and VitE are critical molecules for neural plate and neural tube formation, and neural crest cell migration. Funding Sources The authors received no specific funding for this work.

scholarly journals The hypoxia factor Hif-1α controls neural crest chemotaxis and epithelial to mesenchymal transition

2013 ◽  
Vol 201 (5) ◽  
pp. 759-776 ◽  
Author(s):  
Elias H. Barriga ◽  
Patrick H. Maxwell ◽  
Ariel E. Reyes ◽  
Roberto Mayor
Keyword(s):  
Neural Crest ◽  
Cancer Metastasis ◽  
Epithelial To Mesenchymal Transition ◽  
Neural Crest Cells ◽  
Embryonic Cell ◽  
Zebrafish Embryos ◽  
Mesenchymal Transition ◽  
Metastasis Inhibition ◽  
Neural Crest Migration ◽  
Transcription Factor 1

One of the most important mechanisms that promotes metastasis is the stabilization of Hif-1 (hypoxia-inducible transcription factor 1). We decided to test whether Hif-1α also was required for early embryonic development. We focused our attention on the development of the neural crest, a highly migratory embryonic cell population whose behavior has been likened to cancer metastasis. Inhibition of Hif-1α by antisense morpholinos in Xenopus laevis or zebrafish embryos led to complete inhibition of neural crest migration. We show that Hif-1α controls the expression of Twist, which in turn represses E-cadherin during epithelial to mesenchymal transition (EMT) of neural crest cells. Thus, Hif-1α allows cells to initiate migration by promoting the release of cell–cell adhesions. Additionally, Hif-1α controls chemotaxis toward the chemokine SDF-1 by regulating expression of its receptor Cxcr4. Our results point to Hif-1α as a novel and key regulator that integrates EMT and chemotaxis during migration of neural crest cells.

scholarly journals Modulation of mouse neural crest cell motility by N-cadherin and connexin 43 gap junctions

2001 ◽  
Vol 154 (1) ◽  
pp. 217-230 ◽  
Author(s):  
X. Xu ◽  
W.E.I. Li ◽  
G.Y. Huang ◽  
R. Meyer ◽  
T. Chen ◽  
...  
Keyword(s):  
Gap Junctions ◽  
Neural Crest ◽  
Cell Motility ◽  
Gap Junction ◽  
Connexin 43 ◽  
Neural Crest Cell ◽  
Neural Crest Cells ◽  
Functional Coupling ◽  
Dye Coupling ◽  
Crest Cell

Connexin 43 (Cx43α1) gap junction has been shown to have an essential role in mediating functional coupling of neural crest cells and in modulating neural crest cell migration. Here, we showed that N-cadherin and wnt1 are required for efficient dye coupling but not for the expression of Cx43α1 gap junctions in neural crest cells. Cell motility was found to be altered in the N-cadherin–deficient neural crest cells, but the alterations were different from that elicited by Cx43α1 deficiency. In contrast, wnt1-deficient neural crest cells showed no discernible change in cell motility. These observations suggest that dye coupling may not be a good measure of gap junction communication relevant to motility. Alternatively, Cx43α1 may serve a novel function in motility. We observed that p120 catenin (p120ctn), an Armadillo protein known to modulate cell motility, is colocalized not only with N-cadherin but also with Cx43α1. Moreover, the subcellular distribution of p120ctn was altered with N-cadherin or Cx43α1 deficiency. Based on these findings, we propose a model in which Cx43α1 and N-cadherin may modulate neural crest cell motility by engaging in a dynamic cross-talk with the cell's locomotory apparatus through p120ctn signaling.

Ephrin-B ligands play a dual role in the control of neural crest cell migration

Development ◽  
2002 ◽  
Vol 129 (15) ◽  
pp. 3621-3632 ◽  
Author(s):  
Alicia Santiago ◽  
Carol A. Erickson
Keyword(s):  
Cell Migration ◽  
Actin Cytoskeleton ◽  
Neural Crest ◽  
Cellular Response ◽  
In Situ Hybridisation ◽  
Neural Crest Cell ◽  
Neural Crest Cells ◽  
Eph Receptors ◽  
Ephb Receptors ◽  
Crest Cell

Little is known about the mechanisms that direct neural crest cells to the appropriate migratory pathways. Our aim was to determine how neural crest cells that are specified as neurons and glial cells only migrate ventrally and are prevented from migrating dorsolaterally into the skin, whereas neural crest cells specified as melanoblasts are directed into the dorsolateral pathway. Eph receptors and their ephrin ligands have been shown to be essential for migration of many cell types during embryonic development. Consequently, we asked if ephrin-B proteins participate in the guidance of melanoblasts along the dorsolateral pathway, and prevent early migratory neural crest cells from invading the dorsolateral pathway. Using Fc fusion proteins, we detected the expression of ephrin-B ligands in the dorsolateral pathway at the stage when neural crest cells are migrating ventrally. Furthermore, we show that ephrins block dorsolateral migration of early-migrating neural crest cells because when we disrupt the Eph-ephrin interactions by addition of soluble ephrin-B ligand to trunk explants, early neural crest cells migrate inappropriately into the dorsolateral pathway. Surprisingly, we discovered the ephrin-B ligands continue to be expressed along the dorsolateral pathway during melanoblast migration. RT-PCR analysis, in situ hybridisation, and cell surface-labelling of neural crest cell cultures demonstrate that melanoblasts express several EphB receptors. In adhesion assays, engagement of ephrin-B ligands to EphB receptors increases melanoblast attachment to fibronectin. Cell migration assays demonstrate that ephrin-B ligands stimulate the migration of melanoblasts. Furthermore, when Eph signalling is disrupted in vivo, melanoblasts are prevented from migrating dorsolaterally, suggesting ephrin-B ligands promote the dorsolateral migration of melanoblasts. Thus, transmembrane ephrins act as bifunctional guidance cues: they first repel early migratory neural crest cells from the dorsolateral path, and then later stimulate the migration of melanoblasts into this pathway. The mechanisms by which ephrins regulate repulsion or attraction in neural crest cells are unknown. One possibility is that the cellular response involves signalling to the actin cytoskeleton, potentially involving the activation of Cdc42/Rac family of GTPases. In support of this hypothesis, we show that adhesion of early migratory cells to an ephrin-B-derivatized substratum results in cell rounding and disruption of the actin cytoskeleton, whereas plating of melanoblasts on an ephrin-B substratum induces the formation of microspikes filled with F-actin.

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