Fig. 1

Lysosomes are involved in adult neural stem cell quiescence (A) Whole-mount immunostaining for ZO1 (tight junctions, blue), PCNA (proliferation, magenta), and GFP (transcriptional reporter for deltaA, green), with RNAScope against ascl1a transcripts (preactivation, cyan). Dorsal “apical” view of the pallial ventricular zone at 3 MPF. Green arrow: deltaApos quiescent progenitors, white arrow: deltaAneg qNSC, cyan: pre-activated progenitors, magenta: activated progenitors. Scale bar: 15 μm. (B) KEGG pathways enriched in qNSCs vs. aNSCs based on GO analysis of the RNA-seq data (RFPhigh, GFPneg vs. RFPpos, GFPpos cells from 3 MPF Tg(gfap:egfp); Tg(mcm5:nls-rfp) fish). x axis: enrichment score; numbers next to the bars: number of genes included in this pathway. (C) KEGG pathways enriched in qNSCs at 3.5 months vs. qNSCs at 1.5 months based on GO of the RNA-seq data. As in (B). (D) Normalized mean LysoTracker intensity (bar plot with SD; each dot is 1 independent experiment with 10 pooled brains). Unpaired t test, ∗∗∗p = 0.0003. (E) Experimental design and view of telencephalic organotypic slices after IHC for GFP (NSCs, green) and MCM2 (proliferation, magenta) after control and BafA treatment. Arrows: Mcm2pos,GFPpos NSCs. Scale bars: 10 μm. (F) Proportion of proliferating NSCs (Pcnapos) among all NSCs. Each dot represents 1 animal (with 1–4 treated slices per animal). Bar at median with IQR. Mann-Whitney test, ∗∗p = 0.0026. (G) Whole-mount IHC for Tg(gfap:dTomato) (NSCs, green), and PCNA (proliferation, magenta) in combination with control and sort1a/sort1b-MO-electroporated cells (orange). Dorsal view of the pallial ventricular zone at 3 MPF. Arrows point to electroporated NSCs. Scale bar: 30 μm. (H) Percentage of activated NSCs among all electroporated NSCs 3 days after control- and sort1-MO electroporation. Each dot is 1 fish. Line at median with IQR. Unpaired t test with Welch’s correction, ∗∗p = 0.0064.