John W Sechrist

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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(More)
The vertebrate neural crest arises at the border of the neural plate during early stages of nervous system development; however, little is known about the molecular mechanisms underlying neural crest formation. Here we identify a secreted protein, Noelin-1, which has the ability to prolong neural crest production. Noelin-1 messenger RNA is expressed in a(More)
After unilateral ablation of the avian cranial neural folds, the remaining neuroepithelial cells are able to replace the missing neural crest population (Scherson et al., 1993). Here, we characterize the cellular and molecular nature of this regulative response by defining: (1) the time and location of neural crest cell production by the neuroepithelium;(More)
Cranial sensory ganglia in vertebrates develop from the ectodermal placodes, the neural crest, or both. Although much is known about the neural crest contribution to cranial ganglia, relatively little is known about how placode cells form, invaginate and migrate to their targets. Here, we identify Pax-3 as a molecular marker for placode cells that(More)
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(More)
Hindbrain neural crest cells adjacent to rhombomeres 2 (r2), r4 and r6 migrate in a segmental pattern, toward the first, second and third branchial arches, respectively. Although all rhombomeres generate neural crest cells, those arising from r3 and r5 deviate rostrally and caudally (J. Sechrist, G. Serbedzija, T. Scherson, S. Fraser and M. Bronner-Fraser(More)
Previous studies have suggested that the rostrocaudal patterning of branchial arches in the vertebrate embryo derives from a coordinate segmental specification of gene expression in rhombomeres (r) and neural crest. However, expression of the Krox-20 gene is restricted to neural crest cells migrating to the third branchial arch, apparently from r5, whereas(More)
Our previous studies have shown that hindbrain neural tube cells can regulate to form neural crest cells for a limited time after neural fold removal (Scherson, T., Serbedzija, G., Fraser, S. E. and Bronner-Fraser, M. (1993). Development 188, 1049-1061; Sechrist, J., Nieto, M. A., Zamanian, R. T. and Bronner-Fraser, M. (1995). Development 121, 4103-4115).(More)
The largest of the cranial ganglia, the trigeminal ganglion, relays cutaneous sensations of the head to the central nervous system. Its sensory neurons have a dual origin from both ectodermal placodes and neural crest. Here, we show that the birth of neurons derived from the chick ophthalmic trigeminal placode begins prior to their ingression (HH11), as(More)
We have examined neurotransmitter plasticity in postmitotic cholinergic neurons isolated from 6.5- to 11-day-old embryonic quail ciliary ganglia. Purified neurons were labeled with DiI, transplanted into the trunk of young chick embryos, and assayed for catecholamine content and [3H]thymidine uptake 4 to 5 days later. For ciliary neurons derived from 6.5-(More)