The fine structure of the microgametocytes and macrogametocytes of eimeria tenella, 1968

The ultrastructure of microgametocytes and macrogametocytes of Eimeria tenella was studied with a Phillips 100-C electron microscope. Twenty-two-day old coccidia free chickens were infected with 300,000 to 600,000 sporulated oocysts. Seven days after infection, the chickens were sacrificed; the ceca were removed and processed for electron microscopy. Macrogametocytes and microgametocytes were observed in large vacuoles of the host epithelial cell. The surface of the gametocytes was bounded by a normal unit membrane that had osmiophilic masses lying underneath in several places. The macrogametocytes contained a well developed endoplasmic reticulum, glycogen granules, and lipoid bodies. Wall-forming bodies and dark bodies were found frequently in the cytoplasm of the older stages. Many small cup-shaped micropores and invaginations were observed in the cell surface. Microgametocytes were observed in different stages of development. In early stages of development, electron dense nuclear material was found in the center of the nucleus and near the membrane of the nucleus. In older stages of development, the electron dense nuclear material was arranged peripherally in the nucleus