Immunoglobulin light chain gene rearrangement

Light chain rearrangement is a stepwise process. (A) Specific V and J segments are joined (eg, V3-J2), and then rearrange with Ck. The rearranged DNA strand is transcribed into mRNA after splicing out of additional redundant V and J regions and create a functional kappa light chain. (B) In case of non-functional VJ segments, exhaustive rearrangement continues that leads to the elimination of the Ck region. This process brings together the intron recombination signal sequence (intronRSS) and kappa-deleting signal joint (Kde-sj), which are excised with Ck, creating a byproduct termed kappa-deleting recombination excision circle (KREC). At this point lambda light chain will be created and expressed.