COMPARISON OF RAG GENE-EXPRESSION IN NORMAL AND TRANSFORMED PRECURSORLYMPHOCYTES

Analyses of mechanisms that regulate V(D)J recombination have relied h eavily on the use of transformed precursor lymphocyte cell lines. We n ow show that such lines have highly variable and frequently Low levels of recombination activating genes (RAG)-l and -2 gene expression. We also show that expression levels of the RAG genes can vary > 100-fold between different subcloned cells of an individual pre-B line. We disc uss these findings in the context of normal regulation of RAG gene exp ression and the implication for the use of transformed pre-B cell line s as models for studying control of V(D)J recombination activity.