Project description:Neurogenesis and gliogenesis continue in the Ventricular-Subventricular Zone (V-SVZ) of the adult rodent brain. B1 cells are radial glia-derived astroglial cells that function as primary progenitors or neural stem cells (NSCs) in the V-SVZ. B1 cells, which have an apical contact with the ventricle, decline during early postnatal life, yet neurogenesis continues into adulthood. We found that a second population of V-SVZ astroglial cells (B2 cells), that do not contact the ventricle, function as NSCs in the adult brain. B2 cell numbers increase postnatally, remain constant in 12-month-old mice, and decrease by 18 months. Transcriptomic analysis revealed differences between B1 and B2 cells and shows that like B1 cells, B2 cells can be quiescent or activated. Transplantation and lineage tracing of B2 cells demonstrate their function as primary progenitors for adult neurogenesis. This study reveals that NSC function is relayed from B1 to B2 progenitors to maintain adult neurogenesis.
Project description:B2 cells were purified from spleen by CD19 Microbeads. B1 cells were purified from peritoneal cavity lavage by CD19 microbeads, followed by a depletion of CD23+ cells. RNA was prepared and differential gene expression analysis performed.
Project description:The experiment aimed at determining the genes that are under the control of the Ikaros transcription factor in mouse splenic B1 and B2 B lymphocyte subsets. To this aim, we used Ikf/f R26-CreERT2+ (Cre+) or Ikf/f R26-CreERT2- (Cre-) mice, which correspond to mice with floxed null alleles for Ikzf1 (Heizmann et al., JEM 210:2823-32, 2013) that were crossed with the R26-CreERT2 mice, which harbor a knock-in of the cDNA encoding the tamoxifen (TAM) inducible CreERT2 recombinase in the Rosa26 gene (Badea et al, J. Neurosci 23:2314-22, 2003). 6-8 week-old mice were injected daily with TAM for 3d (50mg/kg). Mice were sacrificed 10d after the first injection, and splenic B1 and B2 B cell populations sorted by flow cytometry. Splenic B1 and B2 cells from mice with induced deletion of Ikaros
Project description:We have comprehensively interrogated wild type B1 and B2 B lineage cells and their progenitors. In mice bearing a conditional deletion of Dnmt3a in the B lineage, we integrated a variety of whole-genome profiling approaches including WGBS, TAB-Seq, RNA-seq, ATAC-Seq and CUT&RUN. The results reveal a stable “foundational methylome” in all B cells that establishes lymphocyte lineage identity. Superimposed on this foundational methylome is a “dynamic methylome” which is differentially modulated in B1 and B2 B cells by the coincident activity/recruitment of DNMT3A and TET enzymes.
Project description:We have comprehensively interrogated wild type B1 and B2 B lineage cells and their progenitors. In mice bearing a conditional deletion of Dnmt3a in the B lineage, we integrated a variety of whole-genome profiling approaches including WGBS, TAB-Seq, RNA-seq, ATAC-Seq and CUT&RUN. The results reveal a stable “foundational methylome” in all B cells that establishes lymphocyte lineage identity. Superimposed on this foundational methylome is a “dynamic methylome” which is differentially modulated in B1 and B2 B cells by the coincident activity/recruitment of DNMT3A and TET enzymes.
