CHANGES IN THE V-H GENE REPERTOIRE OF DEVELOPING PRECURSOR B-LYMPHOCYTES IN MOUSE BONE-MARROW MEDIATED BY THE PRE-B-CELL RECEPTOR

The V-H repertoire on both H chain alleles of normal and lambda 5-defi cient B lineage cells were analyzed by single-cell PCR. The mu H chain s were tested for their capacity to form a pre-B cell receptor. In bon e marrow, D-proximal V-H genes were found preferentially expressed in lambda 5-deficient pre-B cells and in a newly identified early c-kit() cytoplasmic mu H chain(+) pre-B cell population of normal mice. Only half of the mu H chains expressed in these cells have the capacity to form a pre-B cell receptor. Representation of the D-proximal V-H gene s was found suppressed on the productive but not on the nonproductive V(H)DJ(H) rearranged alleles of c-kit(-) preB-II cells and splenic lam bda 5-deficient B cells. More than 95% of the mu H chains expressed in preB-II cells can form a pre-B cell receptor. These results demonstra te that the pre-B cell receptor in normal mice and the B cell receptor in lambda 5-deficient mice mediate a shift in the V-H repertoire.