Antisense intergenic transcription in V(D)J recombination

Abstract

Antigen receptor genes undergo variable, diversity and joining (V(D)J) recombination, which requires ordered large-scale chromatin remodeling. Here we show that antisense transcription, both genic and intergenic, occurs extensively in the V region of the immunoglobulin heavy chain locus. RNA fluorescence in situ hybridization demonstrates antisense transcription is strictly developmentally regulated and is initiated during the transition from DJ_H to VDJ_H recombination and terminates concomitantly with VDJ_H recombination. Our data show antisense transcription is specific to the V region and suggest transcripts extend across several genes. We propose that antisense transcription remodels the V region to facilitate V_H-to-DJ_H recombination. These findings have wider implications for V(D)J recombination of other antigen receptor loci and developmental regulation of multigene loci.