DEFECTIVE DEVELOPMENT OF THE CRANIOFACIAL DIGESTIVE COMPLEX OF XENOPUS-LAEVIS AFTER TREATMENT WITH ENDOGENOUS GALACTOSIDE-BINDING LECTIN ORITS HAPTEN INHIBITOR THIODIGALACTOSIDE/

The regions of the developing craniofacial skeleton and gut of Xenopus laevis have been confronted in vivo with purified embryonic galactosi de-binding lectin or its hapten inhibitor thiodigalactoside (TDG). Con frontation was carried out at stage 24-26 (cranial neural crest migrat ing). Further development of the head skeleton and gut has been monito red in living animals and in histological cross-sections of selected h ead regions. Lectin treatment correlates with the development of large r heads than controls. TDG treatment correlates with the development o f narrower heads than controls. After both treatments, head cartilages are composed of fewer total chondrocytes. Both neural crest and non-n eural crest cartilages are affected. The gut forms larger, irregular c oils after lectin or TDG confrontation. The results suggest that galac toside-binding lectin/galactoside-bearing receptor adhesive interactio ns are important in development of the craniofacial/visceral skeleton and gut.