RESUMO
Objective:To investigate the gene rearrangements in immunoglobulin single switch(S) region during class switch recombination.Methods:An artificial substrate containing single S region(FS?-2) driven by tetracycline-responsive promoter was constructed and underwent CSR in a switch-inducible B lymphoma line was stimulated by cytokines,then the S region mutations and its dependent factors were detected by detected PCR and sequencing.Results:Gene rearrangements including deletions,insertions as well as point mutations could occur even in this single S region after cytokines stimulation;Furthermore,when the upstream promoter was suppressed by its inhibitor,CSR frequency was significantly decreased,indicating a transcription dependent S region recombination.Conclusion:Class switch recombination mechanism can exert a similar effect on single S region.