Somatic rearrangements of the T cell receptor b chain germline DNA

The B chain of the T cell antigen receptor is composed of variable (V), diversity (D), and joining (J) segments. Somatic rearrangements occur with D-J joining followed by V-D-J joining. The random addition and/or deletion of nucleotides (N) forming the NDbN account for the tremendous diversity of the variable region of the b chain.