Neural crest formation in the head of the mouse embryo as observed using a new histological technique

Development ◽  
1981 ◽  
Vol 64 (1) ◽  
pp. 105-120
Author(s):  
David H. Nichols

A histological technique is described which results in the differential staining of neural crest cells. This is used to describe the formation and early migration of crest cells in the head of the mouse embryo. The first indications of crest formation are seen in the midbrain/anterior hindbrain at 3–4 somites where crest cells accumulate in the basal surface of the ectodermal epithelium near the future margin of the neural plate. Shortly thereafter (4–6 somites) these cells disrupt the basal surface of the epithelium and escape as mesenchyme. The apical epithelial cells in this region become the surface ectoderm adjacent to the neural plate. Subsequently, crest is formed from neural plate rather than surface ectoderm. In addition, mesenchyme is formed from presumptive surface ectoderm in a groove in the lateral portion of the fold between the forebrain and the midbrain. By 5–7 somites, crest mesenchyme is formed at all levels of the midbrain, hindbrain, and from the margins of the forebrain adjacent to the optic pits. Because of the bending of the embryonic axis, forebrain crest cells appear to migrate dorsally over the presumptive eye where they are met by ventrally migrating midbrain crest cells. Crest formation continues in the region of the midbrain and hindbrain during, and for an undetermined period after closure of the head folds at between 8 and 16 somites. These results demonstrate differences in the origin and timing of crest formation between chick and mouse. From this may be inferred different patterns of crest migration as well. In addition, the ability to directly observe early crest formation should aid in the analysis of the mechanisms by which epithelial cells are converted into mesenchyme.

Development ◽  
1980 ◽  
Vol 57 (1) ◽  
pp. 71-78
Author(s):  
N. B. Levy ◽  
Ann Andrew ◽  
B. B. Rawdon ◽  
Beverley Kramer

Two- to ten-somite chick embryos were studied in order to ascertain whether, as has been proposed, there exists a ‘ventral neural ridge’ which gives rise to the hypophyseal (Rathke's) pouch. Serial sections and stereo-microscopy were used. The neural ridges arch around the rostral end of the embryo onto the ventral surface of the head, but no evidence was found for their extension to form a ‘ventral neural ridge’ reaching the stomodaeum: in fact a considerable expanse of non-thickened surface ectoderm was seen to separate the ventral portions of the neural ridges from the stomodaeum. The thickening of neural ectoderm which does appear on the ventral surface of the head results from apposition and fusion of the opposite neural ridges flanking the neural plate and thus the tip of the anterior neuropore - the classically accepted mode of closure of the neuropore. These findings are in accord with the generally accepted concept of the origin of thehypophyseal pouch rather than with its derivation from a ‘ventral neural ridge’. No sign of neural crest formation was encountered ventrally; this observation excludes the possibility that endocrine cells of the APUD series could originate from neural crest in this region.


Development ◽  
1991 ◽  
Vol 112 (1) ◽  
pp. 43-50 ◽  
Author(s):  
P. Hunt ◽  
D. Wilkinson ◽  
R. Krumlauf

The structures of the face in vertebrates are largely derived from neural crest. There is some evidence to suggest that the form of the facial pattern is determined by the crest, and that it is specified before migration as to the structures that is is able to form. The neural crest is able to control the form of surrounding, non-neural crest tissues by an instructive interaction. Some of this cranial crest is derived from a region of the hindbrain that expresses Hox 2 homeobox genes in an overlapping and segment-restricted pattern. We have found that neurogenic and mesenchymal neural crest expresses Hox 2 genes from its point of origin beside the neural plate, during migration and after migration has ceased and that rhombomeres 3 and 5 do not have any expressing neural crest beside them. Each branchial arch expresses a different combination or code of Hox genes in a segment-restricted way. The surface ectoderm over the arches initially does not express Hox genes, and later adopts an expression pattern that reflects that of neural crest that has come to underlie it. We suggest that initially the neural plate and neural crest are spatially specified, while the surface ectoderm is unpatterned. Subsequently some positional information could be transferred to the surface ectoderm as a result of an interaction with the neural crest. Given that the role of the homologous genes in insects is position specification, and that neural crest is imprinted before migration, we suggest that Hox 2 genes are providing part of this positional information to the neural crest and hence are involved in patterning the structures of the branchial arches.


2021 ◽  
Author(s):  
Helena Isla-Magrané ◽  
Anna Veiga ◽  
José García-Arumí ◽  
Anna Duarri

Abstract Background: The mammalian eye is a complex organ, comprising different highly specialized tissues derived from various cell linages, including neural ectoderm, surface ectoderm, neural crest and the periocular mesenchyme. Great efforts have been made to design protocols for obtaining ocular cells from human stem cells to model diseases or for regenerative purposes, but the complex crosstalk between ocular cell types driving self-organizing growth is usually limited by restricted experimental designs. Current protocols are overall focused on the isolation of retinal, retinal pigment epithelium (RPE) or corneal cells. Here, we obtained multi-ocular organoids from human induced pluripotent stem cells. Methods: We sought to establish a simple method to induce eye field-commitment in 2D hiPSC cultures with the aim of obtaining self-organized multi-zone ocular progenitor cells in 3 weeks. From this starting point, we generated 3D multi-ocular organoids from the same culture, recapitulating important cellular features of the developing eye. Results: Self-formed multi-zone ocular progenitors in 2D culture spanned the neuroectoderm, surface ectoderm, neural crest and RPE. After manual isolation and growth in suspension, they develop into different 3D multi-ocular organoids composed of multiple cell lineages: retinal pigment epithelium, retina and cornea which could be also generated individually. Within these organoids, retinal regions display correct layering and harbor all major retinal cell subtypes as well as retinal morphological cues, whereas corneal regions closely resemble the transparent ocular-surface epithelium with characteristics of corneal, limbal and conjunctival epithelial cells. RPE also arranged to form organoids composed of polarized pigmented epithelial cells at the surface, full-filled with collagen matrix. Conclusions: The multi-ocular organoids offer a new platform to study early human eye development and disease, and provide a source of human ocular cells from the same individual.


Author(s):  
Julian P. Heath ◽  
Buford L. Nichols ◽  
László G. Kömüves

The newborn pig intestine is adapted for the rapid and efficient absorption of nutrients from colostrum. In enterocytes, colostral proteins are taken up into an apical endocytotic complex of channels that transports them to target organelles or to the basal surface for release into the circulation. The apical endocytotic complex of tubules and vesicles clearly is a major intersection in the routes taken by vesicles trafficking to and from the Golgi, lysosomes, and the apical and basolateral cell surfaces.Jejunal tissues were taken from piglets suckled for up to 6 hours and prepared for electron microscopy and immunocytochemistry as previously described.


2003 ◽  
Vol 296A (2) ◽  
pp. 108-116 ◽  
Author(s):  
Sei Kuriyama ◽  
Akihiro Ueda ◽  
Tsutomu Kinoshita

PLoS ONE ◽  
2014 ◽  
Vol 9 (12) ◽  
pp. e115165 ◽  
Author(s):  
Zuming Zhang ◽  
Yu Shi ◽  
Shuhua Zhao ◽  
Jiejing Li ◽  
Chaocui Li ◽  
...  

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Shashank Gandhi ◽  
Erica J Hutchins ◽  
Krystyna Maruszko ◽  
Jong H Park ◽  
Matthew Thomson ◽  
...  

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.


Development ◽  
1995 ◽  
Vol 121 (2) ◽  
pp. 525-538 ◽  
Author(s):  
M.A. Selleck ◽  
M. Bronner-Fraser

We have investigated the lineage and tissue interactions that result in avian neural crest cell formation from the ectoderm. Presumptive neural plate was grafted adjacent to non-neural ectoderm in whole embryo culture to examine the role of tissue interactions in ontogeny of the neural crest. Our results show that juxtaposition of non-neural ectoderm and presumptive neural plate induces the formation of neural crest cells. Quail/chick recombinations demonstrate that both the prospective neural plate and the prospective epidermis can contribute to the neural crest. When similar neural plate/epidermal confrontations are performed in tissue culture to look at the formation of neural crest derivatives, juxtaposition of epidermis with either early (stages 4–5) or later (stages 6–10) neural plate results in the generation of both melanocytes and sympathoadrenal cells. Interestingly, neural plates isolated from early stages form no neural crest cells, whereas those isolated later give rise to melanocytes but not crest-derived sympathoadrenal cells. Single cell lineage analysis was performed to determine the time at which the neural crest lineage diverges from the epidermal lineage and to elucidate the timing of neural plate/epidermis interactions during normal development. Our results from stage 8 to 10+ embryos show that the neural plate/neural crest lineage segregates from the epidermis around the time of neural tube closure, suggesting that neural induction is still underway at open neural plate stages.


Author(s):  
Gemma Sutton ◽  
Robert N. Kelsh ◽  
Steffen Scholpp

The neural crest (NC) is a multipotent cell population in vertebrate embryos with extraordinary migratory capacity. The NC is crucial for vertebrate development and forms a myriad of cell derivatives throughout the body, including pigment cells, neuronal cells of the peripheral nervous system, cardiomyocytes and skeletogenic cells in craniofacial tissue. NC induction occurs at the end of gastrulation when the multipotent population of NC progenitors emerges in the ectodermal germ layer in the neural plate border region. In the process of NC fate specification, fate-specific markers are expressed in multipotent progenitors, which subsequently adopt a specific fate. Thus, NC cells delaminate from the neural plate border and migrate extensively throughout the embryo until they differentiate into various cell derivatives. Multiple signalling pathways regulate the processes of NC induction and specification. This review explores the ongoing role of the Wnt/β-catenin signalling pathway during NC development, focusing on research undertaken in the Teleost model organism, zebrafish (Danio rerio). We discuss the function of the Wnt/β-catenin signalling pathway in inducing the NC within the neural plate border and the specification of melanocytes from the NC. The current understanding of NC development suggests a continual role of Wnt/β-catenin signalling in activating and maintaining the gene regulatory network during NC induction and pigment cell specification. We relate this to emerging models and hypotheses on NC fate restriction. Finally, we highlight the ongoing challenges facing NC research, current gaps in knowledge, and this field’s potential future directions.


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