Colonization characteristics of enteric neural crest cells: embryological aspects of Hirschsprung's disease

This study explores the development of the enteric nervous system in avian embryos. Particular emphasis was given to colonization characteristics of neural crest cells present in primitive enteric ganglia. By coculturing neuronal and aneuronal gut of quail and chicken embryos, we investigated if and when neural crest cells in primitive enteric ganglia could detach from these ganglia, migrate, and colonize adjacent chicken gut. Quail neural crest cells were identified using the quail nucleolar marker and the HNK-1 antibody. Enteric neurons were identified using three monoclonal antibodies directed against neurofilament proteins. We found that neural crest cells detached from primitive ganglia in neuronal quail gut from E6 till E9, whereas neural crest cells did not leave enteric ganglia from E10 gut. These observations show that there is a transient phase during which enteric neural crest cells can leave the gut. To determine whether neural crest cells could colonize neuronal gut we cocultured neuronal gut or the neural primordium and neuronal chicken gut (E11). We found that quail neural crest cells do not colonize neuronal E11 gut, whereas they do colonize aneuronal gut of the same age. We suggest that aneuronal gut attracts neural crest cells by diffusing factors.