B cell development defect in Hrd1 KO mice is independent of ER stress-associated proteins IRE1α and CHOP.
A, qPCR of B220+ BM cells measuring ER stress-associated genes Xbp1, Chop, Bip, and Erdj3. B, bone marrow from WT, Hrd1 KO, Ire1α KO, and double KO (DKO) littermates were analyzed for B220LOIgM+ pro–B and pre–B cells, B220LOIgM+ immature B cells, and B220HIIgM+ mature B cells. The percentages (C) and total number (D) of B cell development stages as analyzed in B are shown. E, WT, Hrd1 KO, Chop KO, and DKO littermates were analyzed for B cell development as in B. The percentages (F) and total number (G) of B cell development stages as measured in E are shown. Error bars represent S.D. n = 5. *, p < 0.05; **, p < 0.01; ***, p < 0.001.