Transcriptional control of endogenous virus genes in murine lymphocytes

The expression of endogenous retrovirus in murine lymphocytes is under genetic control and also depends on the differentiation state of the lymphocytes. We have used a cDNA probe complementary to induced virus RNA to quantify transcription of virus sequences in lymphocytes from mitogen-stimulated lymphocytes of the AKR, 129/J and Balb/c mice. Balb/c lymphocytes show the clearest case for induction of new virus sequences in response to stimulation. All strains including 129/J show expression of virus sequences in unstimulated control lymphocytes. The data indicate that mitogen induction of endogenous retrovirus is regulated at the transcriptional level.