Atkinson C T
Department of Infectious Diseases, College of Veterinary Medicine, University of Florida, Gainesville 32610.
J Parasitol. 1989 Feb;75(1):135-41.
Ookinetes of Haemoproteus meleagridis were structurally similar to kinetes of other apicomplexan parasites and possessed a polar ring complex (PRC) composed of an electron-lucent polar ring with 25 supporting tines. Fifty subpellicular microtubules were anchored in a circle to the inner surface of the polar ring. A bilayered electron-dense canopy was continuous with the inner layer of the pellicle and formed a caplike cover over the PRC. Embedded rings of actin-sized microfilaments completely encircled each layer of the canopy. Numerous micronemes, 2 smaller preconoidal rings, and a conoid composed of approximately 6 spirally wound, electron-dense tubules were also present. Other organelles were similar to those reported in previous studies of haemosporidian ookinetes. Mature ookinetes of H. meleagridis developed in the midguts of engorged specimens of Culicoides edeni (Diptera: Ceratopogonidae) within 24 hr after a blood meal. Most parasites were found beneath, or embedded within, a peritrophic membrane composed of fine granules and fibrils. The observation of actin-sized microfilaments within the canopy is a previously unrecognized modification of the pellicle that probably supports the anterior end of ookinetes during penetration of the peritrophic membrane.
火鸡疟原虫动合子在结构上与其他顶复门寄生虫的动合子相似，具有一个由电子透明的极环和25根支撑齿组成的极环复合体（PRC）。五十根亚pellicular微管呈环状锚定在极环的内表面。双层电子致密的顶膜与pellicle的内层相连，在PRC上方形成帽状覆盖物。肌动蛋白大小的微丝嵌入环完全环绕顶膜的每一层。还存在许多微线体、2个较小的前锥体环以及一个由大约6根螺旋缠绕的电子致密小管组成的锥体。其他细胞器与先前关于血孢子虫动合子的研究中报道的细胞器相似。火鸡疟原虫的成熟动合子在血餐后24小时内在饱血的伊氏库蠓（双翅目：蠓科）标本的中肠中发育。大多数寄生虫位于由细颗粒和纤维组成的围食膜下方或嵌入其中。在顶膜内观察到肌动蛋白大小的微丝是一种先前未被认识的pellicle修饰，可能在动合子穿透围食膜期间支撑其前端。
