In this study we have cloned the chick Hoxa-2 gene and analysed its expression during early development. We find that Hoxa-2 has a rostral limit of expression in the rhombencephalic neural tube corresponding precisely to the boundary between rhombomeres (r)1 and 2; a limit further rostral than any other Hox gene reported to date. Neural crest migrates from r2 to populate the first branchial arc...

In the preface for his monograph on neural crest in 1950, Horstadius' wrote, "Most text-books of embryology or anatomy make only passing mention of the neural crest as the source of origin of one or two structures in the vertebrate body. Few books devote even as much as a page to this interesting structure." Although the passage of 40 years has seen a revolution in our understanding of the neur...

Neural crest cells are specified at the border between the neural plate and the epiderm. They are capable of differentiating into various somatic cell types, including craniofacial and peripheral nerve tissues. Notch signaling plays important roles during neurogenesis; however, its function during human neural crest development is poorly understood. Here, we generated self-renewing premigratory...

Trunk neural crest cells delaminate from the dorsal neural tube as an uninterrupted sheet; however, they convert into segmentally organized streams before migrating through the somitic territory. These neural crest cell streams join the segmental trajectories of pathfinding spinal motor axons, suggesting that interactions between these two cell types might be important for neural crest cell mig...

The proposed pathways of chick cranial neural crest migration and their relationship to the rhombomeres of the hindbrain have been somewhat controversial, with differing results emerging from grafting and DiI-labelling analyses. To resolve this discrepancy, we have examined cranial neural crest migratory pathways using the combination of neurofilament immunocytochemistry, which recognizes early...

BACKGROUND Although the embryonic expression pattern of ADP ribosylation factor-like 6 interacting protein 1 (Arl6ip1) has been reported, its function in neural crest development is unclear. METHODS/PRINCIPAL FINDINGS We found that knockdown of Arl6ip1 caused defective embryonic neural crest derivatives that were particularly severe in craniofacial cartilages. Expressions of the ectodermal pa...

enamel matrix derivative emdogain (emd) is widely used in periodontal treatment in spite of the fact that its effect on the developing embryo has not been elucidated. the aim of this study was to investigate the teratogenic effect of emd on the rat embryo neural crest cells. the neural crest is a unique population of cells that migrates from the dorsal neural tube along defined pathways and pro...

Neural crest patterning constitutes an important element in the control of the morphogenesis of craniofacial structures. Krox20, a transcription factor gene that plays a critical role in the development of the segmented hindbrain, is expressed in rhombomeres (r) 3 and 5 and in a stream of neural crest cells migrating from r5 toward the third branchial arch. We have investigated the basis of the...

INTRODUCTION Paragangliomas are mostly localized in the adrenal medulla and they are usually pheochromocytomas, derived from the neural crest, but otherwise mesenteric paragangliomas are extremely rare tumors. CASE PRESENTATION In this article we represent a 59-year-old female with an abdominal mass and pain due to mesenteric paraganglioma. CONCLUSIONS Paragangliomas can occur as mesenteric...

The neural crest, an embryonic stem cell population, initially resides within the dorsal neural tube but subsequently undergoes an epithelial-to-mesenchymal transition (EMT) to commence migration. Although neural crest and cancer EMTs are morphologically similar, little is known regarding conservation of their underlying molecular mechanisms. We report that Sip1, which is involved in cancer EMT...