title: Trophospongium-like structures in an insect eye: response of retinula cells of Papilio xuthus (Lepidoptera) to irradiation with ultraviolet light.
abstract: Presumably, as a consequence of a 3-h exposure to light of 350-nm wavelength (1.5 X 10(15) photons/cm2 sec) followed by a period of 20 h of rest in the dark, the four smaller retinula cells in each ommatidium of the eye of the butterfly Papilio xuthus contain a structure in the peripheral regions of their cytoplasm that resembles a portion of a rhabdom. Evidence for and against the view that this unusual, highly ordered arrangement of membranes represents a trophospongium is presented. In view of the fact that the structure in question only occurred at the same time when rhabdomeres were in a process of disintegration or reformation, the authors conclude that the structure in question is involved in the supply or removal of substances during a period of considerable activity of the retinula cell.
mesh_terms: D000818:Animals; D002080:Butterflies / Q000528:radiation effects / Q000648:ultrastructure*; D005123:Eye / Q000528:radiation effects / Q000648:ultrastructure; D007915:Lepidoptera / Q000648:ultrastructure*; D008854:Microscopy, Electron; D014466:Ultraviolet Rays