SOMATIC HYPERMUTATION OF IMMUNOGLOBULIN GENES

The relationship between somatic hypermutation and affinity maturation in the mouse is delineated. Recent work on the anatomical and cellula r site of this process is surveyed. The molecular characteristics of s omatic hypermutation are described in terms of the region mutated and the distinctive patterns of nucleotide changes that are observed. The results of experiments utilizing transgenic mice to find out the minim um cis-acting sequences required to recruit hypermutation are summariz ed. The hypothesis that V gene sequences have evolved in order to targ et mutation to certain sites but not others is discussed. The use that different species make of somatic hypermutation to generate either th e primary or secondary B cell repertoire is considered. Possible molec ular mechanisms for the hypermutation process and future goals of rese arch are outlined.