Figure 6.

PER-ir staining in photoreceptor cells in the compound eyes and ocelli. (a) amPER (green) and DAPI (cyan) double-labelling in the retina of a wholemount brain. DAPI labels the photoreceptor nuclei at a proximal and distal level of the retina (white arrows). At the proximal level only one nuclei per ommatidium is labelled that should correspond to photoreceptor cell 9, whereas in the distal layer 8 nuclei were labelled that are all at slightly different depths in the ommatidium. These should correspond to the nuclei of photoreceptor cells 1–8. The nuclei at the distal level were clearly co-labelled by the amPER antibody, the nuclei of the proximal level only faintly, and in some the PER labelling was barely visible. Note that the cornea of the compound eye is detached from the retina due to the wholemount preparation. (b) amPER, DAPI and PDF (magenta) labelling in superior median brain and the ocelli (OC). The strongest DAPI labelling is found in the Kenyon cells of the mushroom bodies, just dorsally of the median calyces (MC). Strong DAPI labelling is also present in many glial cells in the ocelli. PDF extends into the base of all three ocelli. Here, it can only be seen in the median ocellus. (c) A higher magnification of the left ocellus as indicated in the inset in (b). All photos were taken from foragers' brains. A white arrow points to an arbitrarily chosen nucleus of one photoreceptor cell. Scale bars, 30 µm. Pictures are taken with a 10× objective (numerical aperture: 0.3); distance of z-stacks 2.0; overlay of two stacks.