Roles of erbB4, rhombomere-specific, and rhombomere-independent cues in maintaining neural crest-free zones in the embryonic head.
Within the developing vertebrate head, the migration of neural tube-derived neural crest cells (NCCs) through the cranial mesenchyme is patterned into three streams, with mesenchyme adjacent to rhombomeres (r)3 and r5 maintained NCC-free. The receptor tyrosine kinase erbB4 is expressed within r3 and r5 and is required to maintain the r3-adjacent NCC-free zone in mouse embryos. In this study, we demonstrate that the extent of r3 involvement in patterning mouse NCC migration is restricted to the same dorsolateral region regulated by erbB4. In chick embryos, we show that erbB4 signaling similarly maintains the r3-adjacent NCC-free zone. However, although r5 expresses erbB4, this is insufficient to maintain the r3-adjacent NCC-free zone in grafting experiments where r5 replaced r3, indicating that erbB4 requires additional factors at the A-P level of r3 to pattern NCC migration. Furthermore, we show that the r5-adjacent NCC-free zone is maintained independently of r5, but requires surface ectoderm. Finally, we demonstrate that avian cranial surface ectoderm is patterned molecularly, with dorsolateral surface ectoderm at the levels of r2/3 and r7 expressing the sulfatase QSulf1 in quail, or the orthologue CSulf1 in chick. Aberrant NCC migration into r3-adjacent mesenchyme correlated with more focused QSulf1 expression in r2/3 surface ectoderm.
Golding
Jon P
JP
Division of Neurobiology, National Institute for Medical Research, London NW7 1AA, UK. jon.golding@csc.mrc.ac.uk
Sobieszczuk
Dorothy
D
Dixon
Monica
M
Coles
Edward
E
Christiansen
Jeff
J
Wilkinson
David
D
Gassmann
Martin
M
D000818:Animals; D001483:Base Sequence; D019521:Body Patterning; D002465:Cell Movement / Q000502:physiology; D002642:Chick Embryo; D004475:Ectoderm / Q000166:cytology / Q000502:physiology; D004625:Embryo, Nonmammalian; D066246:ErbB Receptors / Q000378:metabolism*; D005260:Female; D049452:Green Fluorescent Proteins; D006257:Head / Q000196:embryology*; D006801:Humans; D017403:In Situ Hybridization; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D009024:Morphogenesis; D009432:Neural Crest / Q000166:cytology / Q000378:metabolism*; D011784:Quail / Q000196:embryology; D066247:Receptor, ErbB-4; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D015238:Sulfotransferases / Q000235:genetics / Q000378:metabolism
D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; C587689:ERBB4 protein, human; D066246:ErbB Receptors; C587690:Erbb4 protein, mouse; D066247:Receptor, ErbB-4; D015238:Sulfotransferases