DISTRIBUTION OF F-ACTIN IN THE COMPOUND EYE OF THE BLOWFLY, CALLIPHORA-ERYTHROCEPHALA (DIPTERA, INSECTA)

Filaments that probably consist of actin have been observed by electron microscopy in various cells and structures of the compound eye of insects and crustaceans. The overall distribution of F-actin in the compound eye of Calliphora erythrocephala was studied using fluorescent phalloidins as specific probes for F-actin. F-actin is localized (1) in the rhabdomeres, (2) in the Semper cells, (3) in the basement membrane, and (4) associated with desmosomes and membranes. It is concluded that the actin filaments present in the compound eye are involved in mechanical stabilization (e.g., within microvillar processes of the Semper cells and in association with intercellular contacts) and in motile phenomena (e.g., in the rhabdomeric microvilli).