Restricted utilization of V H and D H genes in leukemic rabbit B cells

Polyclonal B cell leukemias have been generated in 17‐ to 20‐day old Eμ‐myc transgenic rabbits. To analyze the repertoire of V H genes utilized in early B cells, eight VDJ genes were cloned from these leukemic cells. The nucleotide sequences of these genes indicated that seven of the eight VDJ genes encoded prototype V H al, V H a2 or V H a3 allotypes. The two VDJ genes encoding V H a1 molecules had V H segments with identical nucleotide sequences; similarly, the V H segments of the four VDJ genes encoding V Ha2 molecules were identical, with the exception of a single base pair. These data suggest that a limited repertoire of V H genes were utilized in the generation of these VDJ genes. The D H segments of these genes were limited to two D H families, D1 and D2, indicating that a restricted repertoire of D H genes also had been utilized. Since these leukemic cells probably developed early in ontogeny, we suggest that this restricted utilization of V H and D H genes is representative of B cells from developmentally immature rabbits.