During B cell maturation, changes occur in Ig genes as the V region assembles from gene fragments. An enzyme called DNA recombinase randomly excises V and J segments from the light chain gene, and splicing at the mRNA level further rearranges the gene. This results in each B cell producing antibodies with a unique variable region capable of binding different antigens.
In B cells, changes in Ig genes occur during the maturation process. The V region of the Ig gene, which codes for the variable region of the antibody, assembles from gene fragments. These gene fragments include the V, D, and J regions. During B cell maturation, an enzyme called DNA recombinase randomly excises V and J segments from the light chain gene. Splicing at the mRNA level further rearranges the gene. This process results in each B cell producing antibodies with a unique variable region capable of binding different antigens.
Learn more about changes in Ig genes during B cell's life