Studies on Xenopus immunoglobulins using monoclonal antibodies.

Monoclonal antibodies raised against Xenopus Ig recognize antigenic determinants on IgM and low mol. wt Ig (LMW Ig or IgY ). On SDS-PAGE two forms of mu were distinguished in the supernatant and cell lysate of tunicamycin-treated spleen cell culture. The two bands of v observed in serum appear to be the result of carbohydrate heterogeneity. The light chains resolved into two distinct bands which differed in peptide maps; the more slowly migrating band of light chain was preferentially associated with v. Patterns of cross-reactivity between the immunoglobulins of 11 species of Xenopus and three subspecies of Xenopus laevis were obtained; the polymorphism of mu and v antigenic determinants and its implications for species divergence are discussed.