..., expression of Hoxa2 , Hoxa3 and Hoxb4 in conjunction with that of the green fluorescent protein has been selectively targeted to the Hox-negative neural folds of the avian embryo prior to the onset of crest cell emigration. Hoxa2 expression precludes the development of the entire facial skeleton. Transgenic...

... tested the capacity of endoderm of the avian neurula to specify the facial skeleton by performing ablations or grafts of defined endodermal regions. Neural crest cells that do not express Hox genes respond to patterning cues produced regionally in the anterior endoderm to yield distinct skeletal...

... Rhombomere Plasticity Facial skeleton Hyoid bone Neural derivative Conotroncus Heart Glandular derivative Pharynx Quail Chick. The neural crest is a highly pluripotent structure that plays a critical role in the construction of the vertebrate head. In addition to neurons and glia...

... of Gans and Northcutt (1983 , Science , 220, 268-274). 23 10 1992 © 1993 by Company of Biologists 1993 neural crest somites cephalic mesenchyme facial skeleton origins of frontal parietal occipital bones sphenoid bones The skull of vertebrates consists of bones...