Fig. 1

RNE invagination is accompanied by basal cell surface area shrinkage and basal actomyosin accumulation.

(A) Schematic representation of RNE morphogenesis from 16 hours post fertilization (hpf) or 15 somite stage (ss) to 24 hpf or 30 ss showing RNE cells that undergo invagination (brown) and rim cells that undergo rim involution (blue). Dotted arrow marks direction of rim involution. (B) Average area of RNE cells at apical (magenta) and basal (green) sides during RNE morphogenesis with mean ± SD. N = 10 embryos. See Figure 1—source data 1. (C,D) Time-lapse imaging of RNE morphogenesis to assess the dynamics of actin marked by GFP-UtrophinCH (C) and of myosin marked by myl12.1-EGFP (D). Arrowhead marks basal actin and myosin enrichment in the RNE. Arrow marks the rim zone lacking the basal enrichment. Videos started around 15 ss. Time in h:min. Frames from Videos 1 and 2. (E,G) Confocal scan of optic cup at 30 ss immunostained for phalloidin (E) and phosphomyosin (G). The arrowhead marks enrichment at the basal side of the RNE. Lookup table indicates maximum and minimum intensity values. (F,H) Normalized average intensity distributions of phalloidin (F) and phosphomyosin (H) in the tissue volume along the apicobasal axis of the RNE at 30 ss. Mean ± SEM. The schematic shows a typical tissue section used for analysis (Also see Figure 1—figure supplement 1D). Tissue sections, n = 14 for phalloidin and n = 15 for phosphomyosin; N = 5 embryos. See Figure 1—source data 2 and 3. All scale bars = 10 µm. Developmental axes are shown next to the panels for orientation. D: Dorsal, V: Ventral; Prox: Proximal, Dist: Distal; A/N: Anterior or nasal, P/T: Posterior or temporal.