Movie 1

Control cells
Time-lapse imaging of control and FMRP-knockout hindbrain cells in culture.
Time-lapse analysis of primary cell cultures prepared from entire hindbrains at E3.5. Hindbrains were electroporated at E2.5 with gRNA_control plasmid (Movie 1) or gRNA₃₊₄ plasmid (Movie 2) to target the dA1 neuronal cell type. Cultures contained a mixture of electroporated (GFP⁺) and non-electroporated cells. Cells were seeded in 48-well plates (n=6 wells for each treatment) and recorded every 6 hours for ~5 days. Time is indicated at the bottom right of the videos. In both movies, GFP⁺ cells are clearly shown to extend neurites with time. Yet the neurite branching and extension rate is enhanced in Movie 2 compared to Movie 1. The corresponding still images from the time lapse imaging are presented in Fig. 9 of the main article.