Development of neural tube basal lamina during neurulation and neural crest cell emigration in the trunk of the mouse embryo

Development ◽  
1986 ◽  
Vol 98 (1) ◽  
pp. 219-236
Author(s):  
M. Martins-Green ◽  
C. A. Erickson

In the trunk of higher vertebrates, the neural crest (NC) cells remain temporarily within the dorsal portion of the neural tube after fusion of the neural folds; shortly thereafter they emigrate, invading surrounding spaces and tissues. One of the factors postulated to be important in the initiation of migration of NC cells is the disruption of the basal lamina (BL) over the dorsal portion of the neural tube. It has been assumed by many that the BL must be discontinuous in order that the NC cells can leave the neural tube; and indeed, experiments performed in our laboratory, and by others, have shown that NC cells cannot penetrate an intact BL. Therefore, we have undertaken a systematic ultrastructural study to evaluate the condition of the BL during neural fold elevation and NC cell emigration. Our results show that: (i) BL surrounding the neural epithelium (NE) becomes progressively more extensive from neural fold to migratory stages. It first forms on the lateral portion of the neuroepithelium of the neural folds and then extends ventrally into the region adjacent to the notochord; (ii) BL becomes continuous beneath the epidermal ectoderm (EE) that overlies the NC cell region only during the terminal stages of NC cell emigration; (iii) BL does not form over the dorsal portion of the neural tube until NC emigration is terminated; and (iv) the morphology of the BL changes as development proceeds. We conclude that absence of a BL over the premigratory NC cell population in the trunk of mouse embryos is a necessary but not a sufficient condition for emigration to take place.

Development ◽  
1987 ◽  
Vol 101 (3) ◽  
pp. 517-533 ◽  
Author(s):  
M. Martins-Green ◽  
C.A. Erickson

One of the factors proposed to control initiation of migration of neural crest (NC) cells is disruption of the basal lamina (BL) that is presumed to exist over the dorsal portion of the neural tube. Previously, we discovered that, in the mouse embryo, a continuous BL is not deposited over the dorsal portion of the neural tube until emigration of the NC cells is terminated. Here, we show that the pattern of BL deposition in chick embryos is similar, but not identical, to that in the mouse. In particular, (i) patches of BL are deposited on the premigratory NC cells in the chick but not in the mouse and (ii) BL is thicker and more interstitial matrix is deposited at the same stage of development in the chick. In addition, immunofluorescent and immunogold labelling of collagen IV, laminin and fibronectin show that (i) patches of young BL contain all three molecules; (ii) collagen IV and laminin are present in BL throughout neurulation but fibronectin either disappears or becomes masked in more mature BL and (iii) collagen IV and especially fibronectin are present in the interstitial matrix, but the relative abundance of fibronectin changes with time. The simultaneous use of immunolabelling for both light and TEM sections has allowed us to determine unambiguously that presence of a basement membrane (light microscopy) does not necessarily imply presence of basal lamina. We conclude that, as in mouse, the BL cannot be involved in the timing of the initiation of migration of NC cells. Our evidence in both the mouse and the chick, together with work in the axolotl, suggests that the basic pattern of BL deposition during neurulation may be a general phenomenon in embryonic development. Moreover, these results, in conjunction with the work of others, suggest that the critical step for initiation of migration of NC cells may be the loss of adhesions between cells.


1992 ◽  
Vol 117 (2) ◽  
pp. 369-382 ◽  
Author(s):  
HJ Hathaway ◽  
BD Shur

Mesenchymal cell migration and neurite outgrowth are mediated in part by binding of cell surface beta 1,4-galactosyltransferase (GalTase) to N-linked oligosaccharides within the E8 domain of laminin. In this study, we determined whether cell surface GalTase functions during neural crest cell migration and neural development in vivo using antibodies raised against affinity-purified chicken serum GalTase. The antibodies specifically recognized two embryonic proteins of 77 and 67 kD, both of which express GalTase activity. The antibodies also immunoprecipitated and inhibited chick embryo GalTase activity, and inhibited neural crest cell migration on laminin matrices in vitro. Anti-GalTase antibodies were microinjected into the head mesenchyme of stage 7-9 chick embryos or cranial to Henson's node of stage 6 embryos. Anti-avian GalTase IgG decreased cranial neural crest cell migration on the injected side but did not cross the embryonic midline and did not affect neural crest cell migration on the uninjected side. Anti-avian GalTase Fab crossed the embryonic midline and perturbed cranial neural crest cell migration throughout the head. Neural fold elevation and neural tube closure were also disrupted by Fab fragments. Cell surface GalTase was localized to migrating neural crest cells and to the basal surfaces of neural epithelia by indirect immunofluorescence, whereas GalTase was undetectable on neural crest cells prior to migration. These results suggest that, during early embryogenesis, cell surface GalTase participates during neural crest cell migration, perhaps by interacting with laminin, a major component of the basal lamina. Cell surface GalTase also appears to play a role in neural tube formation, possibly by mediating neural epithelial adhesion to the underlying basal lamina.


Development ◽  
1986 ◽  
Vol 98 (1) ◽  
pp. 251-268
Author(s):  
J. Sternberg ◽  
S. J. Kimber

The earliest stage of neural crest cell (NCC) migration is characterized by an epitheliomesenchymal transformation, as the cells leave the neural tube. There is evidence that in a number of cell systems this transformation is accompanied by alteration or depletion of associated basement membranes. This study examines the ultrastructural relationship between mouse NCCs and adjacent basement membranes during the earliest stages of migration from the neural tube. Basement membranes were identified by transmission electron microscopy (TEM) and immunofluorescence using antibodies to type-IV collagen. The ultrastructural features of NCCs and their relationship with surrounding tissues were also examined using TEM. In the dorsal region of the neural tube, from which NCCs originate, the basement membrane was depleted or absent, and with the immunofluorescence technique it was shown that this pattern was reflected in a deficit of type-IV collagen. TEM observations indicated that ultrastructurally NCCs differ from their neuroepithelial neighbours only in overall cell shape and their relationship to other cells and the extracellular matrix.


Zygote ◽  
2018 ◽  
Vol 26 (6) ◽  
pp. 457-464 ◽  
Author(s):  
Xiao-tan Zhang ◽  
Guang Wang ◽  
Yan Li ◽  
Manli Chuai ◽  
Kenneth Ka Ho Lee ◽  
...  

SummaryFibroblast growth factor (FGF) signalling acts as one of modulators that control neural crest cell (NCC) migration, but how this is achieved is still unclear. In this study, we investigated the effects of FGF signalling on NCC migration by blocking this process. Constructs that were capable of inducing Sprouty2 (Spry2) or dominant-negative FGFR1 (Dn-FGFR1) expression were transfected into the cells making up the neural tubes. Our results revealed that blocking FGF signalling at stage HH10 (neurulation stage) could enhance NCC migration at both the cranial and trunk levels in the developing embryos. It was established that FGF-mediated NCC migration was not due to altering the expression of N-cadherin in the neural tube. Instead, we determined that cyclin D1 was overexpressed in the cranial and trunk levels when Sprouty2 was upregulated in the dorsal neural tube. These results imply that the cell cycle was a target of FGF signalling through which it regulates NCC migration at the neurulation stage.


Development ◽  
1989 ◽  
Vol 106 (4) ◽  
pp. 809-816 ◽  
Author(s):  
G.N. Serbedzija ◽  
M. Bronner-Fraser ◽  
S.E. Fraser

To permit a more detailed analysis of neural crest cell migratory pathways in the chick embryo, neural crest cells were labelled with a nondeleterious membrane intercalating vital dye, DiI. All neural tube cells with endfeet in contact with the lumen, including premigratory neural crest cells, were labelled by pressure injecting a solution of DiI into the lumen of the neural tube. When assayed one to three days later, migrating neural crest cells, motor axons, and ventral root cells were the only cells types external to the neural tube labelled with DiI. During the neural crest cell migratory phase, distinctly labelled cells were found along: (1) a dorsolateral pathway, under the epidermis, as well adjacent to and intercalating through the dermamyotome; and (2) a ventral pathway, through the rostral portion of each sclerotome and around the dorsal aorta as described previously. In contrast to those cells migrating through the sclerotome, labelled cells on the dorsolateral pathway were not segmentally arranged along the rostrocaudal axis. DiI-labelled cells were observed in all truncal neural crest derivatives, including subepidermal presumptive pigment cells, dorsal root ganglia, and sympathetic ganglia. By varying the stage at which the injection was performed, neural crest cell emigration at the level of the wing bud was shown to occur from stage 13 through stage 22. In addition, neural crest cells were found to populate their derivatives in a ventral-to-dorsal order, with the latest emigrating cells migrating exclusively along the dorsolateral pathway.


Development ◽  
1988 ◽  
Vol 103 (4) ◽  
pp. 743-756 ◽  
Author(s):  
H.H. Epperlein ◽  
W. Halfter ◽  
R.P. Tucker

It is generally assumed that in amphibian embryos neural crest cells migrate dorsally, where they form the mesenchyme of the dorsal fin, laterally (between somites and epidermis), where they give rise to pigment cells, and ventromedially (between somites and neural tube), where they form the elements of the peripheral nervous system. While there is agreement about the crest migratory routes in the axolotl (Ambystoma mexicanum), different opinions exist about the lateral pathway in Xenopus. We investigated neural crest cell migration in Xenopus (stages 23, 32, 35/36 and 41) using the X. laevis-X. borealis nuclear marker system and could not find evidence for cells migrating laterally. We have also used immunohistochemistry to study the distribution of the extracellular matrix (ECM) glycoproteins fibronectin (FN) and tenascin (TN), which have been implicated in directing neural crest cells during their migrations in avian and mammalian embryos, in the neural crest migratory pathways of Xenopus and the axolotl. In premigratory stages of the crest, both in Xenopus (stage 22) and the axolotl (stage 25), FN was found subepidermally and in extracellular spaces around the neural tube, notochord and somites. The staining was particularly intense in the dorsal part of the embryo, but it was also present along the visceral and parietal layers of the lateral plate mesoderm. TN, in contrast, was found only in the anterior trunk mesoderm in Xenopus; in the axolotl, it was absent. During neural crest cell migration in Xenopus (stages 25–33) and the axolotl (stages 28–35), anti-FN stained the ECM throughout the embryo, whereas anti-TN staining was limited to dorsal regions. There it was particularly intense medially, i.e. in the dorsal fin, around the neural tube, notochord, dorsal aorta and at the medial surface of the somites (stage 35 in both species). During postmigratory stages in Xenopus (stage 40), anti-FN staining was less intense than anti-TN staining. In culture, axolotl neural crest cells spread differently on FN- and TN-coated substrata. On TN, the onset of cellular outgrowth was delayed for about 1 day, but after 3 days the extent of outgrowth was indistinguishable from cultures grown on FN. However, neural crest cells in 3-day-old cultures were much more flattened on FN than on TN. We conclude that both FN and TN are present in the ECM that lines the neural crest migratory pathways of amphibian embryos at the time when the neural crest cells are actively migrating. FN is present in the embryonic ECM before the onset of neural crest migration.(ABSTRACT TRUNCATED AT 400 WORDS)


Development ◽  
1991 ◽  
Vol 111 (4) ◽  
pp. 857-866 ◽  
Author(s):  
G.N. Serbedzija ◽  
S. Burgan ◽  
S.E. Fraser ◽  
M. Bronner-Fraser

We have used the vital dye, DiI, to analyze the contribution of sacral neural crest cells to the enteric nervous system in chick and mouse embryos. In order to label premigratory sacral neural crest cells selectively, DiI was injected into the lumen of the neural tube at the level of the hindlimb. In chick embryos, DiI injections made prior to stage 19 resulted in labelled cells in the gut, which had emerged from the neural tube adjacent to somites 29–37. In mouse embryos, neural crest cells emigrated from the sacral neural tube between E9 and E9.5. In both chick and mouse embryos, DiI-labelled cells were observed in the rostral half of the somitic sclerotome, around the dorsal aorta, in the mesentery surrounding the gut, as well as within the epithelium of the gut. Mouse embryos, however, contained consistently fewer labelled cells than chick embryos. DiI-labelled cells first were observed in the rostral and dorsal portion of the gut. Paralleling the maturation of the embryo, there was a rostral-to-caudal sequence in which neural crest cells populated the gut at the sacral level. In addition, neural crest cells appeared within the gut in a dorsal-to-ventral sequence, suggesting that the cells entered the gut dorsally and moved progressively ventrally. The present results resolve a long-standing discrepancy in the literature by demonstrating that sacral neural crest cells in both the chick and mouse contribute to the enteric nervous system in the postumbilical gut.


Development ◽  
1995 ◽  
Vol 121 (4) ◽  
pp. 935-945 ◽  
Author(s):  
E. Birgbauer ◽  
J. Sechrist ◽  
M. Bronner-Fraser ◽  
S. Fraser

Neural crest cell migration in the hindbrain is segmental, with prominent streams of migrating cells adjacent to rhombomeres (r) r2, r4 and r6, but not r3 or r5. This migratory pattern cannot be explained by the failure of r3 and r5 to produce neural crest, since focal injections of the lipophilic dye, DiI, into the neural folds clearly demonstrate that all rhombomeres produce neural crest cells. Here, we examine the dynamics of hindbrain neural crest cell emigration and movement by iontophoretically injecting DiI into small numbers of cells. The intensely labeled cells and their progeny were repeatedly imaged using low-light-level epifluorescence microscopy, permitting their movement to be followed in living embryos over time. These intravital images definitively show that neural crest cells move both rostrally and caudally from r3 and r5 to emerge as a part of the streams adjacent to r2, r4, and/or r6. Within the first few hours, cells labeled in r3 move within and/or along the dorsal neural tube surface, either rostrally toward the r2/3 border or caudally toward the r3/4 border. The labeled cells exit the surface of the neural tube near these borders and migrate toward the first or second branchial arches several hours after initial labeling. Focal DiI injections into r5 resulted in neural crest cell contributions to both the second and third branchial arches, again via rostrocaudal movements of the cells before migration into the periphery. These results demonstrate conclusively that all rhombomeres give rise to neural crest cells, and that rostrocaudal rearrangement of the cells contributes to the segmental migration of neural crest cells adjacent to r2, r4, and r6. Furthermore, it appears that there are consistent exit points of neural crest cell emigration; for example, cells arising from r3 emigrate almost exclusively from the rostral or caudal borders of that rhombomere.


1986 ◽  
Vol 102 (2) ◽  
pp. 432-441 ◽  
Author(s):  
R B Runyan ◽  
G D Maxwell ◽  
B D Shur

Migrating embryonic cells have high levels of cell surface galactosyltransferase (GalTase) activity. It has been proposed that GalTase participates during migration by recognizing and binding to terminal N-acetylglucosamine (GlcNAc) residues on glycoconjugates within the extracellular matrix (Shur, B. D., 1982, Dev. Biol. 91:149-162). We tested this hypothesis using migrating neural crest cells as an in vitro model system. Cell surface GalTase activity was perturbed using three independent sets of reagents, and the effects on cell migration were analyzed by time-lapse microphotography. The GalTase modifier protein, alpha-lactalbumin (alpha-LA), was used to inhibit surface GalTase binding to terminal GlcNAc residues in the underlying substrate. alpha-LA inhibited neural crest cell migration on basal lamina-like matrices in a dose-dependent manner, while under identical conditions, alpha-LA had no effect on cell migration on fibronectin. Control proteins, such as lysozyme (structurally homologous to alpha-LA) and bovine serum albumin, did not effect migration on either matrix. Second, the addition of competitive GalTase substrates significantly inhibited neural crest cell migration on basal lamina-like matrices, but as above, had no effect on migration on fibronectin. Comparable concentrations of inappropriate sugars also had no effect on cell migration. Third, addition of the GalTase catalytic substrate, UDPgalactose, produced a dose-dependent increase in the rate of cell migration. Under identical conditions, the inappropriate sugar nucleotide, UDPglucose, had no effect. Quantitative enzyme assays confirmed the presence of GalTase substrates in basal lamina matrices, their absence in fibronectin matrices, and the ability of alpha-LA to inhibit GalTase activity towards basal lamina substrates. Laminin was found to be a principle GalTase substrate in the basal lamina, and when tested in vitro, alpha-LA inhibited cell migration on laminin. Together, these experiments show that neural crest cells have at least two distinct mechanisms for interacting with the substrate during migration, one that is fibronectin-dependent and one that uses GalTase recognition of basal lamina glycoconjugates.


Development ◽  
1986 ◽  
Vol 91 (1) ◽  
pp. 267-282
Author(s):  
J. Sternberg ◽  
S. J. Kimber

The distribution of the extracellular matrix molecules fibronectin, laminin and entactin was studied in frozen sections of 9½-day mouse embryos in order to relate their presence to neural crest cell migration. It was found that all three components were present in basement membranes, laminin and entactin being mainly restricted to these. Fibronectin was present at high levels in basement membranes and extracellular spaces throughout the embryo, including the regions of neural crest cell migration. Fibronectin is known to affect migration in a variety of cell systems, so its presence in the embryo at the time of migration may indicate that it is influencing cell movement. This influence is likely to be via the cell surface through interactions with other matrix components such as glycosaminoglycans, and possibly entactin and laminin.


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