Figure 6 : Visual organs of T. cystophora and immunohistochemical localization of Tcop13 and Tcop18.

From: Cubozoan genome illuminates functional diversification of opsins and photoreceptor evolution

Figure 6

A) Schematic diagram of the rhopalium. The large (LLE) and small (ULE) complex eyes lie along the medial line, while the pit and slit ocelli are paired laterally. B) Schematic diagram of rhopalium sagittal plane (adapted from O´Connor 2009). C) Sagittal section through the rhopalium. Upper (ULE) and lower (LLE) lens eyes contain the typical components of camera-type eyes: a cornea (C), a lens (L), and a retina consisting of a ciliary layer (CL), a pigment layer (PL) and a neural layer (NL). St – statocyst, S – stalk. D) Schematic representation of the lens eye retina. The ciliary layer (CL) is dominated by the ciliary segments of type-B receptor cells (red). Scattered among the type-B receptor cells are the cone-shaped projections of type-A photoreceptor cells (green). In the neural layer (NL), both receptors types have their cell bodies with nuclei (dark blue); only type-A receptor cell bodies are positive for opsin signal. Projections of type-A photoreceptor cell bodies create a compact layer (LA) surrounding the whole retina. E–H) Confocal images of immuno-histochemical staining for Tcop13 (red), Tcop18 (green), DAPI (blue) in the upper lens eye (ULE). I-L) Large camera-type eye (LLE) retina longitudinal section. M–P) Large camera-type eye retina transverse section. (Scale bars: 50 μm).