XBP-1 does not affect the accumulation of viral DNA in host nuclei, but is required for optimal transcription of viral genes.

<p>Primary MEFs derived from RERT/XBP-1^f/f mice were treated with vehicle (EtOH) or 4-OHT for 48 h and infected with MCMV-GFP at MO1 = 1. DNA was purified from nuclear extracts of infected cells at indicated time points. The number of MCMV genome copies in the nucleus was calculated from qPCR data (A). Samples were loaded on 2% agarose gel (B). Untreated RERT/XBP-1^f/f MEFs were also infected with MCMV or MCMV-CRE and genome copy number was analyzed the same way (C, D). The transcription levels of representative MCMV genes were analyzed by quantitative RT-PCR and were calculated relative to expression levels in EtOH treated cells at 12 hpi (E) or MCMV infected cells (F). Results are shown as mean ±SEM of two (A, C) or three (E, F) replicates. * P<0.05, ** P<0.01.