Fig. 6

Single cell RNA-seq data from germinal centers links PHF19 expression modulation to cell cycle. A PHF19 expression is the highest in cycling GC B-cells and preplasmablasts and plasmablasts. Upper panel shows a UMAP projection and cluster identification from single cell RNAseq profiles of human B cells maturation in tonsils [120]. Lower panel shows UMAP plot showing expression of PHF19 in the different B cells clusters as shown in the upper panel (www.tonsilimmune.org/, accessed on 16 June 2021). B Heatmap displaying the relative expression fold change (log2) of PHF19 and selected genes in clusters of dark zone B cells representing different stages of the cell cycle (data are from [119]. Ten clusters were identified by PhenoGraph in dark zone GC B cells based on the expression of genes associated with the S-G2-M stages of the cell cycle: three clusters of cells transitioning from G1 to S phase (C1, C2 and C3), two clusters in the S-phase (C4 and C5), three clusters of cells transitioning from G2 to M phase (C6, C7 and C8), one cluster in the M-phase (C9) and one cluster of cells transitioning from M to G1 phase (C10). The differential expression analysis is performed by comparing each cluster to all the others. PHF19 expression peaks in the G2-M phase of the cell cycle and this is followed by the modulation of several genes of the PHF19 transcriptional signature