biostudies-literatureUnknown30(13)Brenner SThe quality and quantity of BCR signals impact on cell fate decisions of B lymphocytes. Here, we describe novel gene-targeted mice, which in the context of normal VDJ recombination show hypomorphic expression of immunoglobulin μ heavy chain (μHC) mRNA levels and hence lower pre-BCR and BCR levels. Hypomorphic expression of μHC leads to augmented selection processes at all stages of B-cell development, noticeably at the expansion of pre-B cells, the positive selection of immature B lymphocytes in the bone marrow and the selection of the follicular (FO), marginal zone (MZ) and B1 B-lymphocyte compartment in peripheral lymphoid organs. Immature as well as mature FO and MZ B lymphocytes in the peripheral lymphoid organs express lower levels of the receptor for B-cell activating factor (BAFF). The EMBO journal2705-18https://www.ebi.ac.uk/biostudies/studies/S-EPMC3155302biostudies-literatureA hypomorphic IgH-chain allele affects development of B-cell subsets and favours receptor editing.PMC3155302Steinbart TWelzel HYu PBrenner SDrewel DNitschke LWeisel FSchweizer AHartel EPotzsch SBrandl AMudde GCWinkler THfalseA hypomorphic IgH-chain allele affects development of B-cell subsets and favours receptor editing.The quality and quantity of BCR signals impact on cell fate decisions of B lymphocytes. Here, we describe novel gene-targeted mice, which in the context of normal VDJ recombination show hypomorphic expression of immunoglobulin μ heavy chain (μHC) mRNA levels and hence lower pre-BCR and BCR levels. Hypomorphic expression of μHC leads to augmented selection processes at all stages of B-cell development, noticeably at the expansion of pre-B cells, the positive selection of immature B lymphocytes in the bone marrow and the selection of the follicular (FO), marginal zone (MZ) and B1 B-lymphocyte compartment in peripheral lymphoid organs. Immature as well as mature FO and MZ B lymphocytes in the peripheral lymphoid organs express lower levels of the receptor for B-cell activating factor (BAFF). 2011-01-01T00:00:00Z2011 May2025-05-29T20:29:03.376Z2019-03-27T03:07:57ZS-EPMC31553022162334610.1038/emboj.2011.168