Fig. 4.

Coablation results in delayed PR regeneration. (A) Schematic of assay timeline and paradigm for rod cell and macrophage/microglia coablation for data shown in B–F. Whole-retina intravital images across the indicated time series (dots in the Inv line) track changes in YFP expression in individual fish over time. (B–D) Representative z-projection confocal images of rho:YFP-NTR;mpeg1:Tomato;mpeg1:NTR-YFP larvae from untreated control (B–B′′′), rod-ablated (C–C′′′), and coablated (D–D′′′) groups at days 1, 3, 4, and 6 of recovery. (E–E′′) Images showing complete overlap between mpeg1:NTR-YFP (E) and mpeg1:Tomato (E′) reporter expression (40× magnification), which facilitated subtraction of NTR-YFP–expressing microglia cells from all retinal YFP volume calculations. A merged image is shown in E′′. (F) Quantification of YFP expression intensity—as an indication of rod cell number—for all conditions at each time point. For both ablation conditions, rod cell loss is evident at +1 d of recovery (Upper Left). In retinas in which only rod cells were ablated, YFP intensity begins to approach control levels at +3 d of recovery (Upper Right). In contrast, coablation causes a delay in rod cell regeneration such that evidence of new rod cells cannot be detected until day 4 of recovery (Lower Left) before finally approaching control levels at +6 d of recovery (Lower Right). Statistics: The Wilcoxon rank-sum test was used for paired comparisons; corresponding P values are provided in Table S3; bolded letters denote pairs showing reproducible differences; italicized letters denote pairs with no discernible differences.