The role of cell death in the midgut epithelium in Filientomon takanawanum (Protura).

Midgut epithelium in Filientomon takanawanum is composed of epithelial cells and single, sporadic regenerative cells. In 80% of analyzed specimens midgut epithelial cells, as fat body and gonads, are infected with rickettsia-like microorganism. In non-infected specimens young and completely differentiated epithelial cells are distinguished among epithelial cells. Characteristic for midgut epithelial cells regionalization in organelles distribution is not observed. Autophagy is the sporadic process, but if the cytoplasm of epithelium cells possesses numerous spherites and sporadic autophagosomes, the apoptosis begins. Necrosis is observed sporadically. In the midgut epithelium cells of about 80% of analyzed specimens rickettsia-like microorganisms are observed. The more rickettsia-like microorganisms occur in the cytoplasm, the more autophagosomes are formed, and the process of apoptosis proceeds intensively.