Mouse Models revealed the Mechanisms for Somatic Hypermutation and Class Switch Recombination of Immunoglobulin Genes

The production of specific antibodies involves three diversification processes: V(D)J recombination, somatic hyper mutation (SHM), and class switch recombination (CSR). This chapter summarizes the many genetically manipulated mice that form the basis for the understanding of the biochemical basis of SHM and CSR. Although genetic defects in humans and studies done with cultured cells and cell-free biochemical systems are very important in advancing one's knowledge about the enzymes involved in these processes, it should be evident that mouse models lacking each of these enzymes were absolutely crucial, not only because they revealed the various pathways and activities in which they were involved but also because they provided an understanding of the relative importance of each of these pathways in vivo.