Mechanisms that control antigen receptor variable region gene assembly.

The somatic assembly of antigen receptor genes--known as V(D)J recombination--is a highly regulated process at several different levels. V(D)J rearrangement is limited to stages of early B and T cell development by the lymphoid specific expression of recombinase activity. A common recombinase is apparently responsible for the rearrangement of all antigen receptor loci. Thus, the tissue specific and ordered rearrangement of each antigen receptor locus must depend on controlling their 'accessibility' to the recombinase. Here, we outline recent work that has contributed to the current understanding of mechanisms that control V(D)J rearrangement.