An SEM analysis of neural crest migration in the mouse

Development ◽  
1983 ◽  
Vol 74 (1) ◽  
pp. 97-118
Author(s):  
C. A. Erickson ◽  
J. A. Weston
Keyword(s):  
Neural Crest ◽  
Basal Lamina ◽  
Neural Tube ◽  
Neural Crest Cells ◽  
Sem Analysis ◽  
Basement Membranes ◽  
Dorsal Neural Tube ◽  
Trunk Neural Crest ◽  
Unique Cell ◽  
Neural Crest Migration

The cellular morphology and migratory pathways of the trunk neural crest are described in normal mouse embryos, and in embryos homozygous for Patch in which neural crest derivatives develop abnormally. Trunk neural crest cells initially appear in 8½-day embryos as a unique cell population on the dorsal neural tube surface and are relatively rounded. Once they begin to migrate the cells flatten and orient somewhat tangentially to the neural tube, and advance ventrad between the somites and neural tube. At the onset of migration neural crest cells extend lamellipodia onto the surface of the tube while detaching their trailing processes from the lumenal surface. The basal lamina on the dorsal neural tube is discontinuous when cell migration begins in this region. As development proceeds, the basal lamina gradually becomes continuous from a lateral to dorsal direction and neural crest emigration is progressively confined to the narrowing region of discontinuous basal lamina. Cell separation from the neural tube ceases concomitant with completion of a continuous basement membrane. Preliminary observations of the mutant embryos reveal that abnormal extracellular spaces appear and patterns of crest migration are subsequently altered. We conclude that the extracellular matrix, extracellular spaces and basement membranes may delimit crest migration in the mouse.

Regulation of the onset of neural crest migration by coordinated activity of BMP4 and Noggin in the dorsal neural tube

Development ◽  
1999 ◽  
Vol 126 (21) ◽  
pp. 4749-4762 ◽  
Author(s):  
D. Sela-Donenfeld ◽  
C. Kalcheim
Keyword(s):  
Neural Crest ◽  
Neural Tube ◽  
Specific Inhibitor ◽  
Neural Crest Cells ◽  
Concomitant Treatment ◽  
Neural Tubes ◽  
Dorsal Neural Tube ◽  
Dependent Inhibition ◽  
Neural Crest Migration

For neural crest cells to engage in migration, it is necessary that epithelial premigratory crest cells convert into mesenchyme. The mechanisms that trigger cell delamination from the dorsal neural tube remain poorly understood. We find that, in 15- to 40-somite-stage avian embryos, BMP4 mRNA is homogeneously distributed along the longitudinal extent of the dorsal neural tube, whereas its specific inhibitor noggin exists in a gradient of expression that decreases caudorostrally. This rostralward reduction in signal intensity coincides with the onset of emigration of neural crest cells. Hence, we hypothesized that an interplay between Noggin and BMP4 in the dorsal tube generates graded concentrations of the latter that in turn triggers the delamination of neural crest progenitors. Consistent with this suggestion, disruption of the gradient by grafting Noggin-producing cells dorsal to the neural tube at levels opposite the segmental plate or newly formed somites, inhibited emigration of HNK-1-positive crest cells, which instead accumulated within the dorsal tube. Similar results were obtained with explanted neural tubes from the same somitic levels exposed to Noggin. Exposure to Follistatin, however, had no effect. The Noggin-dependent inhibition was overcome by concomitant treatment with BMP4, which when added alone, also accelerated cell emigration compared to untreated controls. Furthermore, the observed inhibition of neural crest emigration in vivo was preceded by a partial or total reduction in the expression of cadherin-6B and rhoB but not in the expression of slug mRNA or protein. Altogether, these results suggest that a coordinated activity of Noggin and BMP4 in the dorsal neural tube triggers delamination of specified, slug-expressing neural crest cells. Thus, BMPs play multiple and discernible roles at sequential stages of neural crest ontogeny, from specification through delamination and later differentiation of specific neural crest derivatives.

An experimental study on neural crest migration in Barbus conchonius (Cyprinidae, Teleostei), with special reference to the origin of the enteroendocrine cells

Development ◽  
1981 ◽  
Vol 62 (1) ◽  
pp. 309-323
Author(s):  
C. H. J. Lamers ◽  
J. W. H. M. Rombout ◽  
L. P. M. Timmermans
Keyword(s):  
Neural Crest ◽  
Neural Tube ◽  
Ganglion Cells ◽  
Neural Crest Cells ◽  
Enteroendocrine Cells ◽  
Pigment Cells ◽  
Transplantation Technique ◽  
Spinal Ganglion Cells ◽  
Neural Crest Origin ◽  
Neural Crest Migration

A neural crest transplantation technique is described for fish. As in other classes ofvertebrates, two pathways of neural crest migration can be distinguished: a lateroventral pathway between somites and ectoderm, and a medioventral pathway between somites and neural tube/notochord. In this paper evidence is presented for a neural crest origin of spinal ganglion cells and pigment cells, and indication for such an origin is obtained for sympathetic and enteric ganglion cells and for cells that are probably homologues to adrenomedullary and paraganglion cells in the future kidney area. The destiny of neural crest cells near the developing lateral-line sense organs is discussed. When grafted into the yolk, neural crest cells or neural tube cells appear to differentiate into ‘periblast cells’; this suggests a highly activating influence of the yolk. Many neural crest cells are found around the urinary ducts and, when grafted below the notochord, even within the urinary duct epithelium. These neural crest cells do not invade the gut epithelium, even when grafted adjacent to the developing gut. Consequently enteroendocrine cells in fish are not likely to have a trunkor rhombencephalic neural crest origin. Another possible origin of these cells will be proposed.

scholarly journals Bimodal function of chromatin remodeler Hmga1 in neural crest induction and Wnt-dependent emigration

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Shashank Gandhi ◽  
Erica J Hutchins ◽  
Krystyna Maruszko ◽  
Jong H Park ◽  
Matthew Thomson ◽  
...  
Keyword(s):  
Neural Crest ◽  
Neural Tube ◽  
Neural Crest Cells ◽  
Neural Plate ◽  
Chromatin Remodeler ◽  
Lineage Specification ◽  
Dorsal Neural Tube ◽  
Neural Crest Development ◽  
Neural Plate Border ◽  
Canonical Wnt

During gastrulation, neural crest cells are specified at the neural plate border, as characterized by Pax7 expression. Using single-cell RNA sequencing coupled with high-resolution in situ hybridization to identify novel transcriptional regulators, we show that chromatin remodeler Hmga1 is highly expressed prior to specification and maintained in migrating chick neural crest cells. Temporally controlled CRISPR-Cas9-mediated knockouts uncovered two distinct functions of Hmga1 in neural crest development. At the neural plate border, Hmga1 regulates Pax7-dependent neural crest lineage specification. At premigratory stages, a second role manifests where Hmga1 loss reduces cranial crest emigration from the dorsal neural tube independent of Pax7. Interestingly, this is rescued by stabilized ß-catenin, thus implicating Hmga1 as a canonical Wnt activator. Together, our results show that Hmga1 functions in a bimodal manner during neural crest development to regulate specification at the neural plate border, and subsequent emigration from the neural tube via canonical Wnt signaling.

Inhibition of noggin expression in the dorsal neural tube by somitogenesis: a mechanism for coordinating the timing of neural crest emigration

Development ◽  
2000 ◽  
Vol 127 (22) ◽  
pp. 4845-4854 ◽  
Author(s):  
D. Sela-Donenfeld ◽  
C. Kalcheim
Keyword(s):  
Neural Crest ◽  
Neural Tube ◽  
Neural Crest Cells ◽  
Paraxial Mesoderm ◽  
Dorsal Neural Tube ◽  
Progressive Loss ◽  
Crest Cell ◽  
Rostral Part

We have previously shown that axial-dependent delamination of specified neural crest cells is triggered by BMP4 and negatively regulated by noggin. Increasing activity of BMP4 towards the rostral part of the axis is achieved by graded expression of noggin in the dorsal neural tube, the latter being high opposite unsegmented mesoderm, and progressively downregulated facing epithelial and dissociating somites, coinciding in time and axial level with initial delamination of neural crest cells (Sela-Donenfeld, D. and Kalcheim, C. (1999) Development 126, 4749–4762). Here we report that this gradient-like expression of noggin in the neuroepithelium is controlled by the paraxial mesoderm. Deletion of epithelial somites prevented normal downregulation of noggin in the neural tube. Furthermore, partial ablation of either the dorsal half or only the dorsomedial portion of epithelial somites was sufficient to maintain high noggin expression. In contrast, deletion of the segmental plate had no effect. These data suggest that the dorsomedial region of developing somites produces an inhibitor of noggin transcription in the dorsal neural tube. Consistent with this notion, grafting dissociating somites in the place of the unsegmented mesoderm precociously downregulated the expression of noggin and triggered premature emigration of neural crest progenitors from the caudal neural tube. Thus, opposite the unsegmented mesoderm, where noggin expression is high in the neural tube, BMP4 is inactive and neural crest cells fail to delaminate. Upon somitogenesis and further dissociation, the dorsomedial portion of the somite inhibits noggin transcription. Progressive loss of noggin activity releases BMP4 from inhibition, resulting in crest cell emigration. We propose that this inhibitory crosstalk between paraxial mesoderm and neural primordium controls the timing of neural crest delamination to match the development of a suitable mesodermal substrate for subsequent crest migration.

scholarly journals Effects of Shh and Noggin on neural crest formation demonstrate that BMP is required in the neural tube but not ectoderm

Development ◽  
1998 ◽  
Vol 125 (24) ◽  
pp. 4919-4930 ◽  
Author(s):  
M.A. Selleck ◽  
M.I. Garcia-Castro ◽  
K.B. Artinger ◽  
M. Bronner-Fraser
Keyword(s):  
Neural Crest ◽  
Sonic Hedgehog ◽  
Neural Tube ◽  
Neural Crest Cells ◽  
Neural Plate ◽  
Bmp Signaling ◽  
Neural Tube Closure ◽  
Dorsal Neural Tube ◽  
Neural Ectoderm ◽  
Tube Closure

To define the timing of neural crest formation, we challenged the fate of presumptive neural crest cells by grafting notochords, Sonic Hedgehog- (Shh) or Noggin-secreting cells at different stages of neurulation in chick embryos. Notochords or Shh-secreting cells are able to prevent neural crest formation at open neural plate levels, as assayed by DiI-labeling and expression of the transcription factor, Slug, suggesting that neural crest cells are not committed to their fate at this time. In contrast, the BMP signaling antagonist, Noggin, does not repress neural crest formation at the open neural plate stage, but does so if injected into the lumen of the closing neural tube. The period of Noggin sensitivity corresponds to the time when BMPs are expressed in the dorsal neural tube but are down-regulated in the non-neural ectoderm. To confirm the timing of neural crest formation, Shh or Noggin were added to neural folds at defined times in culture. Shh inhibits neural crest production at early stages (0-5 hours in culture), whereas Noggin exerts an effect on neural crest production only later (5-10 hours in culture). Our results suggest three phases of neurulation that relate to neural crest formation: (1) an initial BMP-independent phase that can be prevented by Shh-mediated signals from the notochord; (2) an intermediate BMP-dependent phase around the time of neural tube closure, when BMP-4 is expressed in the dorsal neural tube; and (3) a later pre-migratory phase which is refractory to exogenous Shh and Noggin.

scholarly journals Migrating neural crest cells in the trunk of the avian embryo are multipotent

Development ◽  
1991 ◽  
Vol 112 (4) ◽  
pp. 913-920 ◽  
Author(s):  
S.E. Fraser ◽  
M. Bronner-Fraser
Keyword(s):  
Neural Crest ◽  
Neural Tube ◽  
Sympathetic Neurons ◽  
Morphological Characteristics ◽  
Neural Crest Cells ◽  
Cell Types ◽  
Sympathetic Ganglia ◽  
Avian Embryo ◽  
Developmental Potential ◽  
Trunk Neural Crest

Trunk neural crest cells migrate extensively and give rise to diverse cell types, including cells of the sensory and autonomic nervous systems. Previously, we demonstrated that many premigratory trunk neural crest cells give rise to descendants with distinct phenotypes in multiple neural crest derivatives. The results are consistent with the idea that neural crest cells are multipotent prior to their emigration from the neural tube and become restricted in phenotype after leaving the neural tube either during their migration or at their sites of localization. Here, we test the developmental potential of migrating trunk neural crest cells by microinjecting a vital dye, lysinated rhodamine dextran (LRD), into individual cells as they migrate through the somite. By two days after injection, the LRD-labelled clones contained from 2 to 67 cells, which were distributed unilaterally in all embryos. Most clones were confined to a single segment, though a few contributed to sympathetic ganglia over two segments. A majority of the clones gave rise to cells in multiple neural crest derivatives. Individual migrating neural crest cells gave rise to both sensory and sympathetic neurons (neurofilament-positive), as well as cells with the morphological characteristics of Schwann cells, and other non-neuronal cells (both neurofilament-negative). Even those clones contributing to only one neural crest derivative often contained both neurofilament-positive and neurofilament-negative cells. Our data demonstrate that migrating trunk neural crest cells can be multipotent, giving rise to cells in multiple neural crest derivatives, and contributing to both neuronal and non-neuronal elements within a given derivative.(ABSTRACT TRUNCATED AT 250 WORDS)

The regeneration of the cephalic neural crest, a problem revisited: the regenerating cells originate from the contralateral or from the anterior and posterior neural fold

Development ◽  
1996 ◽  
Vol 122 (11) ◽  
pp. 3393-3407 ◽  
Author(s):  
G. Couly ◽  
A. Grapin-Botton ◽  
P. Coltey ◽  
N.M. Le Douarin
Keyword(s):  
Neural Crest ◽  
Neural Tube ◽  
Hox Genes ◽  
Experimental Situation ◽  
Neural Crest Cells ◽  
Fate Map ◽  
Somite Stage ◽  
Dorsal Neural Tube ◽  
Ventral Neural Tube ◽  
Branchial Arches

The mesencephalic and rhombencephalic levels of origin of the hypobranchial skeleton (lower jaw and hyoid bone) within the neural fold have been determined at the 5-somite stage with a resolution corresponding to each single rhombomere, by means of the quail-chick chimera technique. Expression of certain Hox genes (Hoxa-2, Hoxa-3 and Hoxb-4) was recorded in the branchial arches of chick and quail embryos at embryonic days 3 (E3) and E4. This was a prerequisite for studying the regeneration capacities of the neural crest, after the dorsal neural tube was resected at the mesencephalic and rhombencephalic level. We found first that excisions at the 5-somite stage extending from the midmesencephalon down to r8 are followed by the regeneration of neural crest cells able to compensate for the deficiencies so produced. This confirmed the results of previous authors who made similar excisions at comparable (or older) developmental stages. When a bilateral excision was followed by the unilateral homotopic graft of the dorsal neural tube from a quail embryo, thus mimicking the situation created by a unilateral excision, we found that the migration of the grafted unilateral neural crest (quail-labelled) is bilateral and compensates massively for the missing crest derivatives. The capacity of the intermediate and ventral neural tube to yield neural crest cells was tested by removing the chick rhombencephalic neural tube and replacing it either uni- or bilaterally with a ventral tube coming from a stage-matched quail. No neural crest cells exited from the ventral neural tube but no deficiency in neural crest derivatives was recorded. Crest cells were found to regenerate from the ends of the operated region. This was demonstrated by grafting fragments of quail neural fold at the extremities of the excised territory. Quail neural crest cells were seen migrating longitudinally from both the rostral and caudal ends of the operated region and filling the branchial arches located inbetween. Comparison of the behaviour of neural crest cells in this experimental situation with that showed by their normal fate map revealed that crest cells increase their proliferation rate and change their migratory behaviour without modifying their Hox code.

scholarly journals Segmental migration of trunk neural crest: time-lapse analysis reveals a role for PNA-binding molecules

Development ◽  
1995 ◽  
Vol 121 (11) ◽  
pp. 3733-3743 ◽  
Author(s):  
C.E. Krull ◽  
A. Collazo ◽  
S.E. Fraser ◽  
M. Bronner-Fraser
Keyword(s):  
Neural Crest ◽  
Neural Crest Cells ◽  
Time Lapse ◽  
Light Level ◽  
Explant Culture ◽  
Peanut Agglutinin ◽  
Trunk Neural Crest ◽  
Neural Crest Migration ◽  
Molecular Bases ◽  
First Time

Trunk neural crest cells migrate through the somites in a striking segmental fashion, entering the rostral but not caudal sclerotome, via cues intrinsic to the somites. Attempts to define the molecular bases of these cues have been hampered by the lack of an accessible assay system. To examine trunk neural crest migration over time and to perturb candidate guiding molecules, we have developed a novel explant preparation. Here, we demonstrate that trunk regions of the chicken embryo, placed in explant culture, continue to develop apparently normally for 2 days. Neural crest cells, recognized by prelabeling with DiI or by poststaining with the HNK-1 antibody, migrate in the somites of the explants in their typical segmental pattern. Furthermore, this paradigm allows us to follow trunk neural crest migration in situ for the first time using low-light-level videomicroscopy. The trajectories of individual neural crest cells were often complex, with cells migrating in an episodic mode encompassing forward, backward and lateral movements. Frequently, neural crest cells migrated in close-knit groups of 2–4 cells, moving at mean rates of migration of 10–14 microns/hour. Treatment of the explants with the lectin peanut agglutinin (PNA) both slowed the rate and altered the pattern of neural crest migration. Neural crest cells entered both the rostral and caudal halves of the sclerotome with mean rates of migration ranging from 6 to 13 microns/hour. These results suggest that peanut agglutinin-binding molecules are required for the segmental patterning of trunk neural crest migration. Because this approach permits neural crest migration to be both observed and perturbed, it offers the promise of more direct assays of the factors that influence neural crest development.

A role for rhoB in the delamination of neural crest cells from the dorsal neural tube

Development ◽  
1998 ◽  
Vol 125 (24) ◽  
pp. 5055-5067 ◽  
Author(s):  
J.P. Liu ◽  
T.M. Jessell
Keyword(s):  
Neural Crest ◽  
Cell Fate ◽  
Neural Tube ◽  
Neural Crest Cell ◽  
Neural Crest Cells ◽  
Bmp Signaling ◽  
Dorsal Neural Tube ◽  
Rho Family ◽  
Neural Crest Differentiation ◽  
Crest Cell

The differentiation of neural crest cells from progenitors located in the dorsal neural tube appears to involve three sequential steps: the specification of premigratory neural crest cell fate, the delamination of these cells from the neural epithelium and the migration of neural crest cells in the periphery. BMP signaling has been implicated in the specification of neural crest cell fate but the mechanisms that control the emergence of neural crest cells from the neural tube remain poorly understood. To identify molecules that might function at early steps of neural crest differentiation, we performed a PCR-based screen for genes induced by BMPs in chick neural plate cells. We describe the cloning and characterization of one gene obtained from this screen, rhoB, a member of the rho family GTP-binding proteins. rhoB is expressed in the dorsal neural tube and its expression persists transiently in migrating neural crest cells. BMPs induce the neural expression of rhoB but not the more widely expressed rho family member, rhoA. Inhibition of rho activity by C3 exotoxin prevents the delamination of neural crest cells from neural tube explants but has little effect on the initial specification of premigratory neural crest cell fate or on the later migration of neural crest cells. These results suggest that rhoB has a role in the delamination of neural crest cells from the dorsal neural tube.

Control of pathfinding by the avian trunk neural crest

Development ◽  
1988 ◽  
Vol 103 (Supplement) ◽  
pp. 63-80 ◽  
Author(s):  
Carol A. Erickson
Keyword(s):  
Neural Crest ◽  
Basal Lamina ◽  
Chondroitin Sulphate ◽  
Three Dimensional ◽  
Neural Crest Cells ◽  
Tractional Force ◽  
Trunk Neural Crest ◽  
Adhesive Molecules ◽  
Crest Cell ◽  
Precocious Development

We have determined the pathways taken by the trunk neural crest of quail and examined the parameters that control these patterns of dispersion. Using antibodies that recognize migratory neural crest cells (HNK-1), we have found that the crest cells take three primary pathways: (1) between the ectoderm and somites, (2) within the intersomitic space and (3) through the anterior somite along the basal surface of the myotome. The parameters controlling dispersion patterns of neural crest cells are several. The pathways are filled with at least two adhesive molecules, laminin and fibronectin, to which neural crest cells adhere tenaciously in culture. The pattern of migration through the somite may be accounted for in part by the precocious development of the basal lamina of the dermamyotome in the anterior half of the somite; this basal lamina contains both fibronectin and laminin and the neural crest cells prefer to migrate on it. In contrast, the regions into which the crest cells do not invade are filled with relatively nonadhesive molecules such as chondroitin sulphate. Some of the pathways are filled with hyaluronic acid, which stimulates the migration of neural crest cells when they are cultured in three-dimensional gels, presumably by opening spaces. Neural crest cells are also constrained to stay within the pathways by basal laminae, which act as barriers and through which crest cells do not go. Therefore, crest pathways are probably defined by several redundant factors. The directionality of crest cell migration is probably due to contact inhibition, which can be demonstrated in tissue culture. Various grafting experiments have suggested that chemotaxis and haptotaxis do not play a role in controlling the dispersion of the crest cells away from the neural tube. We have documented the extraordinary ability of neural crest cells to disperse in the embryo, even when they are grafted into sites in which they would normally not migrate. We have evidence that the cells' production of plasminogen activator, a proteolytic enzyme, and also the minimal tractional force that crest cells exert on the substratum as they migrate, contribute to this migratory ability.

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