Fig. 4

Fig. 4 Transcriptomic and functional homologies between quiescent NSCs in zebrafish and mammalian astrocytes.

a Cluster mapping between zebrafish dorsal RG (this study) and astroglia in the mouse telencephalon. Colors: scaled AUROC scores. b Scoring of mouse astroglial cells from¹⁰ (left) and⁵³ (right) for genes enriched in zebrafish q4 over q2. Top: annotated clustering of astroglia from each dataset. Bottom: Enrichment score for orthologs of genes overexpressed in zebrafish q4 over q2. c Scheme of the clonal recombination and chase times used to assess the neurogenic potential of q4 RG. d UMAP comparing timp4.3 and her4.1 expression in qRG. Colors: variable counts. e, f, Quantitative analysis of timp4.3 expression in clones at 6dpi. e,e’, Representative image of recombined cells (mCherry immunohistochemistry -IHC-, red, large spot) in Dm (ZO1 IHC, white, to delimit apical NSC surfaces), with whole-mount RNAscope for timp4.3. timp4.3 dots are segmented in all apical cells (e, magenta) or shown only in recombined clones (e’, cyan). Scale bar 5 μm. ftimp4.3 expression (number of dots) in non-recombined (control) vs recombined (induced) cells at 6dpi (see Source Data file). For each boxplot: lower and upper bounds: 25th and 75th percentiles, internal line: median, whiskers extend to the extrema. Individual values overlaid as black dots. n = 135 and 103 for induced and control cells respectively. Statistical comparison: Two-sided Mann-Whitney U test, p:0.07; effect size: Cliff’s delta (0.14) with a 95% confidence interval (−0.01, 0.28). g Proportion of clones per hemisphere containing only RG over time. Boxplots drawn as in f. n = 10, 6, 5, 4, 6, 11, 9, 10, 11 clone-containing hemispheres at 6, 18, 30, 64, 91, 125, 183, 308, 507 days respectively (see Source Data file). h Representative image of smISH for ascl1a (green) and timp4.3 (magenta) in adult zebrafish Dm (dorsal view). ZO1 IHC delimits apical NSC surfaces (dotted lines). Scale bar 7 μm. i Boostrapped estimate of the proportion of RG-only clones after a 507-day chase (red), versus proportions of q4 cells, estimated in situ with RNAScope (green) or in scRNAseq (blue).