Start of μ-chain production by the further two-step rearrangements of immunoglobulin heavy chain genes on one chromosome from a DJ(H)/DJ(H) configuration in an Abelson virus-transformed cell line: Evidence of secondary DJ(H) complex formation

A variant was selected from an Abelson virus-transformed cell line with identifiable and distinguishable DJ(H) rearrangements on both chromosomes. Southern blotting experiments suggested that this variant resulted from a secondary DJ(H) complex formation accompanied with the deletion of one of the DJ(H) rearrangements on the same chromosome. Furthermore, this variant started making μ-chains by the further functional join of a V(H) gene to the secondarily formed DJ(H) complex. Thus, we describe here the first evidence of a secondary DJ(H) complex formation.