Sequences of Cμ and the V_H1 Family in LG7, a Clonable Strain of Xenopus, Homozygous for the Immunoglobulin Loci

Abstract

Twenty-eight heavy-chain variable (V_H1) region genes and the immunoglobulin (IgM) heavy-chain constant region of an isogenic Xenopus hybrid, X. laevis/X, gilli, LG7, have been sequenced. The LG7 clone represents the first Xenopus hybrid that is homozygous for the IgH locus. The V_H1 family was specifically investigated because V_H1 genes are used by the antibodies produced during the Xenopus antidinitrophenol (DNP) response, These V_H1 germ-line sequences establish a so-called ”dictionary— that is available for studying somatic hypermutational mechanisms in immunized frogs.