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Fig. 1 Atoh7+ progenitors divide asymmetrically to produce a PRpr and a sister cell Schematic of the Atoh7+ lineage and open questions in fate decisions. Cell fate assignment strategy based on (left) mode of migration and (right) morphology and final neuronal position in the laminated retina. Plot on the left indicates typical movement trajectories for each cell type. Montage of Atoh7+ progenitor division generating an RGC (magenta dot) and a PRpr (cyan dot). Dashed line indicates the apical side and arrowhead points to RGC axon. atoh7:GFP-CAAX (Atoh7, grey). Scale bar 10 μm. Montage of Atoh7+ progenitor division generating an HC (orange dot) and a PRpr (cyan dot). Dashed line indicates the apical side. atoh7:GFP-CAAX (Atoh7, grey). Scale bar 10 μm. Montage of Atoh7+ progenitor division generating an AC (yellow dot) and a PRpr (cyan dot). Dashed line indicates the apical side and arrowhead points to basal dendrites. atoh7:GFP-CAAX (Atoh7, grey). Scale bar 10 μm. Photoconversion experiment. A 405 laser was used to photoconvert isolated cells labelled with Crx:H2BDendra at 42 hpf. Twenty-four hours after photoconversion, photoconverted PRs were assessed. (Top) Schematic of the experiment and (bottom) representative images of the different steps of the experiment. Crx:H2BDendra (green) and photoconverted Crx:H2BDendra (magenta). Scale bar 10 μm, white line indicates apical side of the retina. Schematics of the Atoh7+ lineage showing possible outcomes of Atoh7+ divisions and PRpr divisions. Distribution of fates for the sister cell of the PRpr acquired during early and late neurogenic windows. Amacrine cells and horizontal cells are pooled into the Inhibitory neurons (IN) category. N = 13 embryos, n = 96 Atoh7+ divisions. Mean and 95% CI are indicated. Event plot of all divisions analysed in (H).