Double break-point in the match for the mutator

Mammalian B cells use heretical genetic mechanisms to generate an astonishingly diverse array of antibody molecules. In fact, the creation of a single antibody molecule involves three separate events that permanently alter genomic DNA. The variable (V) regions of the immunoglobulin gene are created when smaller gene segments are recombined, the constant (C) regions of the immunoglobulin genes can be replaced or ‘switched’ at the gene level and single base pair changes can appear within the recombined antibody variable region genes in a process referred to as somatic hypermutation.