Excystation and Development in Cell Culture of Irradiated Oocysts of Eimeria tenella*

SYNOPSIS. Irradiation of sporulated oocysts of Eimeria tenella with 7,000; 13,000–14,000; or 20,000–21,000 rads does not kill the sporozoites or diminish their ability to penetrate cells in chicken kidney cell culture. Schizogony is the developmental stage most influenced by irradiation of oocysts. Effects on division and formation of merozoites correspond to irradiation levels.