scholarly journals Misexpression of BRE gene in the developing chick neural tube affects neurulation and somitogenesis

2015 ◽  
Vol 26 (5) ◽  
pp. 978-992 ◽  
Author(s):  
Guang Wang ◽  
Yan Li ◽  
Xiao-Yu Wang ◽  
Manli Chuai ◽  
John Yeuk-Hon Chan ◽  
...  

This is the first study of the role of BRE in embryonic development using early chick embryos. BRE is expressed in the developing neural tube, neural crest cells, and somites. BRE thus plays an important role in regulating neurogenesis and indirectly somitogenesis during early chick embryo development.

2016 ◽  
Vol 64 (23) ◽  
pp. 4705-4715 ◽  
Author(s):  
Chao-jie Wang ◽  
Guang Wang ◽  
Xiao-yu Wang ◽  
Meng Liu ◽  
Manli Chuai ◽  
...  

Development ◽  
1990 ◽  
Vol 108 (4) ◽  
pp. 543-558 ◽  
Author(s):  
G. Couly ◽  
N.M. Le Douarin

Areas of the superficial cephalic ectoderm, including or excluding the neural fold at the same level, were surgically removed from 3-somite chick embryos and replaced by their counterparts excised from a quail embryo at the same developmental stage. Strips of ectoderm corresponding to the presumptive branchial arches were delineated, thus defining anteroposterior ‘segments’ (designated here as ‘ectomeres’) that coincided with the spatial distribution of neural crest cells arising from the adjacent levels of the neural fold. This discrete ectodermal metamerisation parallels the segmentation of the hindbrain into rhombomeres. It seems, therefore, that not only is the neural crest patterned according to its rhombomeric origin but that the superficial ectoderm covering the branchial arches may be part of a larger developmental unit that includes the entire neurectoderm, i.e., the neural tube and the neural crest.


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 ◽  
1998 ◽  
Vol 125 (15) ◽  
pp. 2963-2971 ◽  
Author(s):  
S. Nakagawa ◽  
M. Takeichi

During the emergence of neural crest cells from the neural tube, the expression of cadherins dynamically changes. In the chicken embryo, the early neural tube expresses two cadherins, N-cadherin and cadherin-6B (cad6B), in the dorsal-most region where neural crest cells are generated. The expression of these two cadherins is, however, downregulated in the neural crest cells migrating from the neural tube; they instead begin expressing cadherin-7 (cad7). As an attempt to investigate the role of these changes in cadherin expression, we overexpressed various cadherin constructs, including N-cadherin, cad7, and a dominant negative N-cadherin (cN390), in neural crest-generating cells. This was achieved by injecting adenoviral expression vectors encoding these molecules into the lumen of the closing neural tube of chicken embryos at stage 14. In neural tubes injected with the viruses, efficient infection was observed at the neural crest-forming area, resulting in the ectopic cadherin expression also in migrating neural crest cells. Notably, the distribution of neural crest cells with the ectopic cadherins changed depending on which constructs were expressed. Many crest cells failed to escape from the neural tube when N-cadherin or cad7 was overexpressed. Moreover, none of the cells with these ectopic cadherins migrated along the dorsolateral (melanocyte) pathway. When these samples were stained for Mitf, an early melanocyte marker, positive cells were found accumulated within the neural tube, suggesting that the failure of their migration was not due to differentiation defects. In contrast to these phenomena, cells expressing non-functional cadherins exhibited a normal migration pattern. Thus, the overexpression of a neuroepithelial cadherin (N-cadherin) and a crest cadherin (cad7) resulted in the same blocking effect on neural crest segregation from neuroepithelial cells, especially for melanocyte precursors. These findings suggest that the regulation of cadherin expression or its activity at the neural crest-forming area plays a critical role in neural crest emigration from the neural tube.


2012 ◽  
Vol 74 (9) ◽  
pp. 628-634 ◽  
Author(s):  
Michael I. Dorrell ◽  
Michael Marcacci ◽  
Stephen Bravo ◽  
Troy Kurz ◽  
Jacob Tremblay ◽  
...  

We describe a technique for removing and growing chick embryos in culture that utilizes relatively inexpensive materials and requires little space. It can be readily performed in class by university, high school, or junior high students, and teachers of any grade level should be able to set it up for their students. Students will be able to directly observe the chick’s development from 3 days post-fertilization to the point at which it would normally hatch. Observing embryonic development first hand, including the chick embryos’ natural movements, gives students a full appreciation for the complexity and wonder of development. Students can make detailed observations and drawings, and gain understanding of important principles in developmental biology. Finally, we suggest various ways in which this project can be adapted to allow students in advanced classes to design and implement their own projects for investigating teratogenic effects on development using the ex ovo model of chick development.


Development ◽  
1989 ◽  
Vol 106 (1) ◽  
pp. 85-93 ◽  
Author(s):  
C. Kalcheim ◽  
M.A. Teillet

We have investigated dorsal root ganglion formation, in the avian embryo, as a function of the composition of the paraxial somitic mesoderm. Three or four contiguous young somites were unilaterally removed from chick embryos and replaced by multiple cranial or caudal half-somites from quail embryos. Migration of neural crest cells and formation of DRG were subsequently visualized both by the HNK-1 antibody and the Feulgen nuclear stain. At advanced migratory stages (as defined by Teillet et al. Devl Biol. 120, 329–347 1987), neural crest cells apposed to the dorsolateral faces of the neural tube were distributed in a continuous, nonsegmented pattern that was indistinguishable on unoperated sides and on sides into which either half of the somites had been grafted. In contrast, ventrolaterally, neural crest cells were distributed segmentally close to the neural tube and within the cranial part of each normal sclerotome, whereas they displayed a nonsegmental distribution when the graft involved multiple cranial half-somites or were virtually absent when multiple caudal half-somites had been implanted. In spite of the identical dorsal distribution of neural crest cells in all embryos, profound differences in the size and segmentation of DRG were observed during gangliogenesis (E4–9) according to the type of graft that had been performed. Thus when the implant consisted of compound cranial half-somites, giant, coalesced ganglia developed, encompassing the entire length of the graft. On the other hand, very small, dorsally located ganglia with irregular segmentation were seen at the level corresponding to the graft of multiple caudal half-somites. We conclude that normal morphogenesis of dorsal root ganglia depends upon the craniocaudal integrity of the somites.


Development ◽  
1975 ◽  
Vol 33 (1) ◽  
pp. 43-56
Author(s):  
D. F. Newgreen ◽  
R. O. Jones

This study was carried out in order to determine what factors control the differentiation of certain neural crest cells in the chick embryo. Emphasis was placed on the morphologically and biochemically divergent sensory and sympathetic pathways of differentiation. Embryos were precisely staged according to Hamburger & Hamilton (1951) and it was observed that sensory ganglia with somites, explanted at stages 21–24, gave rise to cells showing formaldehyde-induced fluorescence in more than 25% of explants. These cells were identical in properties to the fluorescent cells of the sympathetic system of embryos of similar age, and appeared by 12 days in vitro. These fluorescent cells did not appear when somites and sensory ganglia explants were maintained separately. The incidence of fluorescent cells in combined explants was considerably reduced or absent when cultures were maintained for 7 days or less, or when the explants were obtainedfrom stage 25–26 embryos. Furthermore, when neural tube was also included in the cultures, the appearance of fluorescent cells was markedly inhibited. The requirement for somitic tissue to induce fluorescent cells in combined explants can be replaced by forelimb-bud tissue. The origin of these cells and the factors that control their differentiation in vitro are discussed with reference to the neural crest origin of the sensory ganglion, and the possible conditions pertaining in vivo in this region.


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