Analysis of mRNA expression in wild-type and Grp78+/− mice. (A) Northern blot analysis of mRNA levels of Grp94, Grp78, and PDI in wild-type (+/+) and Grp78+/− E10.5 embryos. GAPDH and 28S rRNA were used as RNA loading controls. (B) Northern blot analysis of mRNA levels of Grp94, Grp78, and PDI in wild-type (+/+) and Grp78+/− MEFs either left untreated (Ctrl) or treated with 300 nM Tg, 1.5 μg/ml Tu, or 5 mM AzC for 16 h. 28S rRNA was used as an RNA loading control.