PUTATIVE MESENCHYMAL RECEPTOR CELLS FOR MIGRATING NEURAL CREST CELLS IN ANEURAL SEGMENTS OF EMBRYONAL CHICK GUT

Abstract

To clarify the regulation of the neural crest cell migration in the gut, we investigated whether cell adhesion molecules, that are expressed by neural crest cells (NCAM, NgCAM, HNK-1), are also expressed by other cells in aneuronal segments of the gut. We therefore cultured isolated segments of aneuronal gut of four and five day old embryos on the chorioallantoic membrane. Immunostaining, with antibodies directed against cell adhesion molecules, revealed a diffuse band of HNK-1 stained mesenchymal cells, located inside the developing smooth muscle layer. We call this HNK-1 mode I expression. Immunostaining of cultured proximal, innervated segments of the gut of E5 embryos revealed a concentration of the HNK-1 epitope at the sites of the myenteric and submucous plexus. We call this HNK-1 mode II expression. The E/C8 antibody, directed against a neurofilament associated protein, was used to demonstrate presence or absence of neural crest cells in the gut. To determine whether the difference in HNK-1 expression was related to the presence of neural crest cells, we cultured aneuronal gut together with the neural anlage (neural tube and neural crest). Immunostaining revealed that in these co-cultures HNK-1 mode II replaced HNK-1 mode I expression. These results suggest the presence of a subpopulation of mesenchymal cells in the gut, that is involved in neural crest cell migration and aggregation.