VIRUS-LIKE PARTICLES IN RICKETTSIA WITHIN THE MIDGUT EPITHELIAL-CELLS OF GLOSSINA-MORSITANS-CENTRALIS AND GLOSSINA-BREVIPALPIS

The midgut epithelium cells of both teneral and 30-day-old nonteneral Glossina morsitans centralis and Glossina brevipalpis contain nonoccluded, isometric virus-like particles (VLPs) of 40 nm maximum diameter, within a proportion (<5.0%) of the intracellular Rickettsia-like organisms (RLOs) present within the midgut cytoplasm. Similar individual VLPs were also occasionally found within the epithelial cell cytoplasm mainly in close proximity to RLOs. Paracrystalline arrays of empty, electron-lucent spheres were also observed within the nucleoplasm of the RLOs. These lucent particles resemble empty nucleocapsids and are thought to represent an earlier stage in the replication of the virus. The presence of large numbers of virus particles results in a significant increase in the size and shape of the infected RLOs. © 1993 Academic Press, Inc.