Figure 2:

The generation of optimal IG specificities and optimal isotypes in individuals with differing IGH haplotypes. Optimal V alleles are shown in red, and deletion polymorphisms are shown with a cross. Cells with optimal specificities are shown with horizontal hatching and with red IG binding sites. Cells that express the optimal isotype for a particular response are shown with vertical hatching. The success of the response to a pathogen is a consequence of clone sizes, of the fine specificities of antigen-specific cells, and of the ability for class switching to result in expression of optimal isotypes. Heavy chain D and J genes, and light chain genes also contribute to the expression of optimal specificities, but are not shown.