Antibody diversity derives from the combination of several different factors. The antibody molecule consists of a constant region, a variable region and junction (J) regions. In the germline, these sections are encoded by different exons spread along the chromosome. As a B cell develops, these exons re-arrange to be juxtaposed to one another, forming an intact gene. In the mouse there are 200-500 variable regions from which to choose, and 4 different J regions, resulting in ...
This solution goes through how the immune system generates antibodies specific for a hugely diverse array of different proteins.