CYTOCHEMICAL EVIDENCE FOR RNA SYNTHESIS INHIBITION BY FUMAGILLIN

Abstract

Evidence was obtained that fumagillin inhibits RNA synthesis in the microsporidian, Octosporea muscaedomesticae, a pathogen of the blow fly, Phormia regina. Infections, treated with 66 mg fumagillin per liter of 5% sucrose for six hours, were compared to control octosporeoses of the same age with the following techniques: Giemsa stain, pyronin-methyl green, and acridine orange fluorescence. Staining reactions demonstrated an almost complete loss of material from the parasites' cytoplasm; RNase treatment of normal parasites identified this material as RNA. Parasite DNA remained unchanged after fumagillin treatment, as observed by the above techniques.