Expression of transgene in lymphoid tissues. (A) RT-PCR analysis of Eμ-BRD2 expression in different Tg tissues. Lane 1, non-Tg spleen control; lane 2, Tg heart control; lane 3, Tg skeletal muscle control; lane 4, Tg spleen; lane 5, Tg thymus. Primers amplified both endogenous murine message and Tg message. Negative controls without RT verified the RT dependence of the signal (results not shown). (B) Tg expression in Tg B and T cells. The 5′ primer recognizes a Tg vector–specific sequence at the translation start site and the 3′ primer a sequence within the first bromodomain, common to both endogenous and Tg sequences. Analysis was performed with purified B-cell RNA (B220) and T-cell RNA (CD3). Control reaction without reverse transcriptase is shown (–RT control).