Fig. 5.

Structural changes in rhabdoms begin before dark. Confocal images of longitudinal sections of LE rhabdoms immunostained for Ops5. LEs were fixed approximately 30 min after peak illumination during the day (Day), 30 min after sunset (SS+0.5 h) and during deep night (SS+4 h). Clock-driven changes in rhabdom structure are already well underway at the onset of darkness and thus must begin before dark. Images were collected in 0.5 μm steps. Maximum projections of between 10 and 15 sections are shown. Images were intensified in Photoshop and assembled in CorelDraw. Solid arrows, location of the aperture at the base of the lens; open arrows, location of the eccentric cell dendrite. Scale bar, 25 μm.