Evidence for linked expression of latent allotypes of the heavy chain constant and variable regions

C(H) allotypes were determined for rabbit IgG and antibody molecules identified and isolated on the basis of their expression of latent group a (V(H)) allotypic determinants. Serologic and chemical typing of the purified molecules revealed that five out of 10 individual preparations studied expressed d allotypes not present in the rabbit as a nominal allotype. None of the latent V(H)-C(H) combinations represented products of a new or unusual arrangement of V(H) and C(H) structural genes. This result indicates that the molecules with latent allotypes express their V(H) and C(H) allotypes in the same combinations as do their nomal counterparts and do not result from misspairing of separate genes involved in H chain synthesis.