All of them consist of two domains known as constant and variable regions, which are present on both their heavy and light chains.  
Following the expression of the RAG-1 gene, the V and J genes are randomly joined just before the formation of one of the four major portions of these substances.  Susumo Tonegawa first explained their variability in the 1970s by using recombinant DNA cloning and pointing out differences in their kappa and gamma chains.  All of them consist of two domains known as constant and variable regions, which are present on both their heavy and light chains.  Divided into five classes of "I-sub-G's" or immunoglobulins, FTP, name these proteins produced by B cells in response to the presence of an antigen.
Following the expression of the RAG-1 gene, the V and J genes are randomly joined just before the formation of one of the four major portions of these substances.  
antibody (accept early "immunoglobulin")