SUMMARYIntracytoplasmic μ‐positive pre‐B cells (μ+VH315−cells) transformed with Abelson virus continuously produced cells (μ+VH315+cells) that were double‐stained by anti‐μ and anti‐VH315 antibodies which specifically recognized the immunoglobulin heavy chain variable region identical or closely related to that of MOPC315 myeloma protein. Southern blot analysis indicated that the μ+VH315+cells were generated from the μ+VH315‐ cells by the VH315·D·JH2to a germline JH3joining on the non‐productive VH315·D·JH2allele, which resulted in the production of μ‐chains with variable region detectable by anti‐VH315 antibodies. Therefore, it is strongly indicated that VHDJHto JHjoining is not blocked in μ‐chain‐producing pre‐B cells, and thus is
展开▼
