Four of Five RAG-Expressing JCκ−/− Small Pre-BII Cells Have No L Chain Gene Rearrangements

Single cell PCR assays have been further developed that detect over 80% of all VκJκ, VκRS, and VλJλ rearrangements at efficiencies between 70% and 90%. These IgL chain gene rearrangement assays were used with small pre-BII cells that develop in comparably high numbers in the bone marrow of wild-type, Cκ-deficient, and JCκ-deficient homozygous and heterozygous mice. In all of these mice, only 15%–25% of all small pre-BII cells carry VλJλ...