In recent years, the DNA sequence rearrangements, widespread in both prokaryotes and eurkaryotes, have been the subject of intense research effort. Gene Rearrangement describes the latest developments in a number of areas of current interest, including genomic rearrangements in prokaryotes, the molecular basis of antigenic variation in African trypanosomes, and DNA amplification in eukaryotes. This volume complements a previous title in the series, Molecular Immunology, which described DNA rearrangement mechanisms for genes of the immune system.