Organization Of The Immunoglobulin Heavy- And Light-Chain Loci In The Rat

Rats of the genus Rattus norvegicus are undoubtedly one of the most popular animals used for experimental biomedical research. Despite the fact that the initial publications on immunoglobulin (IG) genes and their organization in the rat were shortly behind those of mouse and human, our knowledge on the complexity and organization of the IG loci in this rodent species has been hampered for years, due to lack of (genomic) nucleotide sequence information. The tide turned as of the establishment of most of the genomic nucleotide sequence from the Brown Norway (BN) rat strain. This genomic sequence information allows researchers to more accurately map the IG genes in this so commonly used species. To date, the organization of the rat IGH locus has been described in detail, whereas effort is undertaken to resolve the organization of the IGK and IGL loci. This chapter summarizes the current knowledge on the complexity and organization of the IGH, IGK, and IGL loci in the rat and reveals that the IG loci in this animal bear much resemblance to mouse and human.