Fine structural development of microgamonts of Sarcocystis singaporensis in Python reticulatus.

Three 4-month-old reticulated pythons (Python reticulatus), hatched from eggs laid by a newly caught female from Singapore Island, were fed on muscles of Sarcocystis singaporensis-infected Rattus rattus caught in Singapore. Snakes were sacrificed 5, 6 and 8 days later, the infected tissues were studied by transmission electron microscopy. The present communication summarizes findings on microgamont stages. Both premature and mature microgamonts were already present in the snake sacrificed 5 days post-feeding; young stages, however, were still common 8 days post-infection. Young microgamonts have characteristic, elongated nuclei, which round-up towards the time of microgamete emergence. Microgamonts complete their development within the mucosal epithelial layer; the infected apical epithelial cells undergo degeneration with the loss of the brush border.