The four representations, although different, allow to identify an IG as a receptor of four chains,
themselves organized in domains ("DomainType" concept). VH and VL are V type domains, coded by the
V-D-J region and V-J region, respectively. CL, CH1, CH2 and CH3 are C type domains.
(A) 3D structure,
(B) organization in Ig-like domains,
(C) organization in modules,
(D) regions coded by the V, D, J and C gene types.
The C gene type codes the constant region (CL for the IG-Light-Chain and CH1, hinge, CH2 and CH3 for the IG-Heavy-Chain).
This representation, schematized as a Y shape, is frequently used to represent an IG.