Extended Data Fig. 2: Loss of FMRP impairs cortical neurodevelopment.

a, Quantification of the proportions of TBR2⁺ IPCs, CTIP2⁺ cortical neurons, and SOX2⁺ NPCs in total DAPI⁺ cells in control and FXS-derived forebrain organoids at day 56. Data are presented as mean ± s.e.m. (n = 6 organoids from each line with 15–20 cortical structures analyzed per organoid; ****P < 0.0001, one-way ANOVA). b, c, Loss of FMRP dysregulates distribution of TBR2⁺ intermediate neural progenitor cells. Shown are representative images (b) and quantification (c) of the proportion of TBR2⁺ IPCs in MAP2⁺ layer of both control and FXS-derived forebrain organoids. Yellow dashed lines indicate the borders of VZ-like structures. Data are presented as mean ± s.e.m. (n = 6 organoids from each condition with 15–20 cortical structures analyzed per organoid; ****P < 0.0001, one-way ANOVA). Scale bars: 50 µm.