Fig. 3

Expression of ARL3 and CEP120 in the developing human retina. a Schematic diagram of the development of the layers of the retina from 8PCW to the mature form (adapted from [40]). At 8PCW, not all of the layers are present in the retina. The ONbL is a transitionary layer containing retinal progenitor cells that will develop into various cell types such as photoreceptors, amacrine and bipolar cells; separating into the ONL, OPL, INL, and IPL (the IPL is sometimes visible at 8PCW). The GCL is thicker at 8PCW due to the migration of cells. The mature retina can be divided into layers. The RPE is at the very back of the eye and assists in the removal of waste products from the photoreceptor cells, which transduce light. The ONL, OPL, INL and IPL layers house intermediary cell bodies and dendrites that interact with ganglion cells in the GCL to convey the signal through the optic nerve, formed in the NFL, to the brain (reviewed in [41]). b Human sections of developing eye at 8PCW (b and d) and 14PCW (c and e) stained using RNA Scope to show ARL3 expression (b and c) (red) and CEP120 (d and e) (red) counterstained with Methyl Green (Bi and Di). There is a gradient of ARL3 (Bi) and CEP120 (Di) expression in the retina at 8PCW across multiple retinal layers including the ONbL. At 14 PCW, ARL3 (Ci) and CEP120 (Ei) expression is localised across multiple layers including the photoreceptor cell layer, just below the RPE layer (arrows). GCL, ganglion cell layer; INL, inner nuclear layer; IPL, inner plexiform layer; NFL, nerve fibre layer; ONL, outer nuclear layer; OPL, outer plexiform layer; ONbL, outer neuroblastic layer; RPE, retinal pigment epithelium