IMMUNOGLOBULIN HEAVY-CHAIN GENE ORGANIZATION IN MICE - ANALYSIS OF A MYELOMA GENOMIC CLONE CONTAINING VARIABLE AND ALPHA-CONSTANT REGIONS

The authors have isolated a myeloma genomic DNA clone containing the variable and constant regions of a mouse α chain. Restriction enzyme analyses and electron microscopic R loop mapping have demonstrated that the variable region is separated from the constant region by 6.8 kilobases of intervening DNA. In addition two intervening DNA sequences of 100-200 bases separate the constant region into three approximately equal units. These intervening sequences may separate each of the segments coding for the three constant region domains of the α heavy chain. Southern blot analysis of embryo and myeloma DNA suggests that DNA rearrangement of heavy chain variable and constant regions occurs during the differentiation of antibody-producing cells.