A monoclonal antibody against neural crest-stage Xenopus laevis lectin perturbs craniofacial development of Xenopus.

A monoclonal antibody that we have produced against the neural crest-stage galactoside-binding lectin of Xenopus laevis has been used to confront neural crest cells in Xenopus embryos in vivo. Confronted tadpoles have been raised to stage 47 (premetamorphosis) and examined for jaw defects in whole mounts and tissue sections. Antibody treatment correlates with no grossly defective lower jaw development in 19% of tadpoles. An increase in protrusion of the lower jaw and a decrease in the number of chondrocytes in the head is also noted. Further biochemical studies of the lectin reveal that it is an aggregate. Agglutinating activity resides in doublet protein that binds the monoclonal antibody. The results therefore suggest that interfering with the portion of the lectin complex that has the agglutinating activity can have significant effects on craniofacial development.