Fig. 6

Spatially distinct tectal radial astrocyte subtypes and TBI responses of central-located qRA subtypes across stages (A) UMAP plot showing re-clustering of quiescent radial astrocytes from uninjured OT across four stages. Cells are colored by their identities. qRA, quiescent radial astrocytes. (B) Dot plot showing the expression of marker genes of each qRA subtype in (A). (C) Histograms showing the proportion of each qRA subtype at each stage. (D–J) In situ hybridization of qRA subtype-specific marker genes (zgc:153704, luzp2, ntn1a, rdh10a, tenm3) (red) combined with BLBP immunostaining (green) on the uninjured OT sections of 20-dpf (D–F) and adult (G–J) zebrafish. Left/right panels of each figure represent different regions of the OT as labeled on the images. Boxed areas are shown magnified in the bottom panels. (K, M, O, and Q) Representative images of proliferative radial astrocytes (pRA, PCNA+BLBP+) located at central OT in the uninjured (upper panel) and injured (lower panel) sides of zebrafish at the early-larval (11 dpf–3 dpi) (K), late-larval (17 dpf–3 dpi) (M), juvenile (48 dpf–3 dpi) (O), and adult (4 mpf–3 dpi) (Q) stages. Arrowheads indicate the injury sites. Boxed areas in (M), (O), and (Q) are shown magnified in the right panels; white asterisks in the zoom-in images indicate PCNA+BLBP+ pRA. (L, N, P, and R) Quantification of pRA located at central OT in the uninjured and injured sides of zebrafish at 11 dpf–3 dpi (L, n = 15 animals), 17 dpf–3 dpi (N, n = 8 animals), 48 dpf–3 dpi (P, n = 5 animals), and 4 mpf–3 dpi (R, n = 5 animals) (mean ± SEM; parametric paired t tests; ns, p > 0.05; ∗∗p < 0.01; ∗∗∗p < 0.001). In (D–J), (K), (M), (O), and (Q), dashed lines indicate OT boundaries. Scale bars, 50 μm (D1–J3, K1–K6, M1–M6, O1–O6, Q1–Q6) and 5 μm (zoom-in images). Nuclei are visualized by DAPI (blue).