Antigen Receptor Diversity

How antigen receptor diversity arises, with an antibody light chain as the example.

Genes encoding an antibody molecule’s variable regions are divided up into a series of segments. Here we show a few of the V and J segments of the human light chain gene on chromosome 2 (a different series of light chain gene segments occurs on chromosome 22).
As each B cell is maturing, multiple recombination events remove random chunks of DNA between V and J segments, so that any V segment may end up joined to any J segment. Post-transcriptional processing of the resulting RNA removes the intron between the combined V-J segment and the constant region segment (C).
The finished mRNA encodes the light chain that will be produced by the mature B cell and all of its descendants.