Analysis of antibody diversity: V‐D‐J mRNA nucleotide sequence of four anti‐GAT monoclonal antibodies. A paucigene system using alternate D‐J recombinations to generate functionally similar hypervariable regions

The nucleotide sequence of four anti‐(Glu60‐Ala30‐Tyr10)n (GAT) monoclonal gamma 1 heavy chain mRNAs was determined from codon 10 to 120. This sequence overlaps with the NH2‐terminal amino acid sequence, allowing elucidation of the complete protein sequence encompassing regions VH, D and JH. These sequences, which are highly conserved, indicate that anti‐GAT antibodies expressing the same public idiotypic specificities represent a paucigene system, which uses at least two D‐J combinations leading to functionally similar hypervariable regions involved in the recognition of the dominant Glu‐Tyr determinant. D regions are encoded by D genes which are closely related either to the D‐SP2 or the D.FL16 germ line gene cores.