We have studied the expression of the two membrane δ heavy chains (δ1 and δ2) and the two native IgD structures (IgD1 and IgDII) in neonatal mice. Both δ-chains appear simultaneously during development and neonatal mice, like adults, express equal amounts of δ1 and δ2 IgDI and IgDII also appear simultaneously during ontogeny and in the same ratio as expressed by adult mice of the same strain. Thus, when IgD first appears during ontogeny it shows the same structural heterogeneity as observed in adult mice.
Bibliographical noteFunding Information:
*This work was supported by National Institute of Allergy and Infectious Diseases Grant I-POl-AI 14732. Roberta R. Pollock was supported by National Institutes of Health Training Grant CA 09141. ‘r Current address: Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, U.S.A.