Evidence for the Presence of the Fc Allotypic Marker As8 and the Fd Allotypic Marker Asl in the Same Molecules of Rabbit IgG

Abstract

A number of hypotheses concerning the origin of specificity of antibodies involve the participation of two if not more structural genes for each of the constituent chains (Edelman and Gally, 1967; Hood, Gray, and Dreyer, 1966). Models in which each immunoglobulin polypeptide chain is synthesized in two distinct pieces, corresponding to the variable and the common region (Todd, 1963), and subsequently assembled into a single unit seem to be ruled out by the biosynthetic experiments of Lennox, Knopf, Munro, and Parkhouse, and of Fleischman reported in this volume. Recombination, if it occurs, must take place at the genetic level (DNA or RNA). One example of such an hypothesis involves recombination between a full-length gene coding for the whole chain and a homologous half-length gene coding for the variable part (Smithies, this volume). Recombinational events between the whole gene and the half-length or scrambler gene would give rise to numerous “scrambled”...