Gametocytogenesis of Leucocytozoon caulleryi in In Vitro Culture: Effect of Human Red Blood Cells on the Development of Second-Generation Merozoites

For investigating development of second-generation merozoites of Leucocytozoon caulleryi into mature gametocytes, infected erythrocytes from chickens at 15 d after sporozoites inoculation were cultured in RPMI-1640 modified medium supplemented with 10% horse serum and 0.5 ml of human erythrocytes (type O). When culture was carried out at 37°C in a humidified atmosphere of 5% CO₂ for 7 d, the very small number of second-generation merozoites developed into morphologically mature gametocytes. However, in the high carbon dioxide and low oxygen condition, mature gametocytes weren't observed in cluture. The role of human erythrocytes added has not been clarified yet.