V(D)J RECOMBINATION AND THE CELL-CYCLE

V(D)J recombination is a major source of antigen receptor diversity an d represents the only known form of site-specific DNA rearrangement in vertebrates. V(D)J recombination is initiated by specific DNA cleavag e at recombinational signal sequences and requires components of the g eneral machinery used for double-strand (DS)-break repair The involvem ent of DS cleavage and repair mechanisms suggests that V(D)J recombina tion might be coupled to the cell cycle, as introduction or persistenc e of DS breaks during DNA replication or mitosis could interfere with faithful transmission of genetic information to daughter cells. Here, Weei-Chin Lin and Stephen Desiderio review recent evidence indicating that this is indeed the case and consider some biological implications of this linkage.