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 C_k. 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 nonfunctional VJ segments, exhaustive rearrangement continues that leads to the elimination of the C_k region. This process brings together the intron recombination signal sequence (intronRSS) and kappa-deleting signal joint (Kde-sj), which are excised with C_k, creating a byproduct termed kappa-deleting recombination excision circle (KREC). At this point, lambda light chain will be created and expressed.