Eimeria tenella: further studies on the development of the oocyst.

Aim: The present study investigated the processes of macrogametogenesis and oocyst formation of Eimeria tenella (Xiamen strain), including the formation of wall-forming body1 (WFB1) and wall-forming body 2 (WFB2), the club-shape body and the origin of the residual body during the transformation from a macrogamete to an oocyst.

Method: Transmission electron microscopy was used to follow ultrastructural changes of the organelles during parasite development. Frozen section techniques and special staining were used to determine the chemical composition of the club-shape body.