Fig. 4

Parallel bands of Müller glial scaffolding appear simultaneously with differentiating cones. (A-D) Live imaging of the retinal margin, with Red cone trβ2:tdTomato (red) and Müller glial gfap:EGFP (green) markers. Glial processes completely surround cone and rod photoreceptors, which can be visualized as round ‘holes’ in the GFP label at the level of the OLM. (A-A”) Maximum intensity z-projection. Red cones in the patterned lattice mosaic (white dots) and pre-column zone (magenta dots). (A”) Red cones (white dots) and non-red cones (open white dots) in the patterned lattice mosaic. (Also see Additional file 9: Movies S3 and Additional file 10: Movie S4.) (B-D) Single z-levels focused on the pre-column (B), and patterned (C, D) areas. (E-E”’) Ridge analysis applied to Müller glial profiles in flat-mount of Tg(gfap: EGFP) (green) retina immunolabeled for ZO1 (magenta). (Also see Additional file 7: Figure S4.) Arrows (E-E”) indicate the location of the first ordered column of cone photoreceptors that can be clearly discerned from cell outlines at the level of the OLM (E’). Parallel ridges of Müller glia extend for several iterations into the pre-column zone (E’-E”’). Scale bar: 5 μm (D”)