Fig. 6.

Autophagosome formation is increased in Fnip1 mutants but is not responsible for B-cell deficiency. (A) Bone marrow B cells were permeabilized and stained for S555 phospho-ULK1 (pULK1) and Beclin-1. (B) Bone marrow cells from wild-type or Fnip1 mutant mice (with or without the EμBCL2 transgene) were stained for LC3 in the presence or absence of bafilomycin (which inhibits degradation of LC3-II expressing autophagosomes). Hardy fractions were gated as in Fig. 3 (A, B220⁺CD43⁺BP-1⁻CD24⁻; B, B220⁺CD43⁺BP-1⁻CD24⁺; C+C′, B220⁺CD43⁺BP-1⁺CD24⁺; D, B220⁺CD43⁻IgM⁻IgD⁻; E, B220⁺CD43⁻IgM⁻IgD+; F, B220⁺CD43⁻IgM⁺IgD⁺). (C) Absolute numbers of bone marrow B-cell subsets and splenic B220+ cells in mice with or without a homozygous null allele of Tp53. (D) LC3-staining intensity in B220⁺CD19⁺ B cells from Fnip1^ham/hamAtg3^fl/flERT2cre⁺ mice treated with tamoxifen or vehicle control. Cells were incubated in the presence or absence of bafilomycin. (E) Absolute numbers of bone marrow B-cell subsets and splenic B220+ cells in Fnip1^ham/hamAtg3^fl/flERT2cre⁺ mice treated with vehicle (Atg3-sufficient) or tamoxifen (Atg3-deficient).