Speer C A
Veterinary Research Laboratory, Montana State University, Bozeman 59717.
J Protozool. 1988 Aug;35(3):379-81. doi: 10.1111/j.1550-7408.1988.tb04111.x.
Eimeria bovis has two types of first-generation merozoites with distinct ultrastructural characteristics. Type I merozoites were relatively large (means = 13.2 x 1.5 micron) and crescent-shaped, contained numerous micronemes and amylopectin granules, had a posteriorly located nucleus and a conical-shaped posterior tip, and were highly motile and capable of penetrating cultured cells. Type II merozoites were small (means = 5.9 x 0.9 micron) and spindle-shaped, had a centrally-located nucleus, few micronemes, few or no amylopectin granules, a dome-shaped posterior tip and little motility, and appeared to be incapable of penetrating cultured cells. It is possible that these two types of merozoites have considerably different roles in the life cycle of E. bovis.
牛艾美球虫有两种具有不同超微结构特征的第一代裂殖子。I型裂殖子相对较大（平均尺寸 = 13.2×1.5微米），呈新月形，含有大量微线体和支链淀粉颗粒，细胞核位于后部，后端呈圆锥形，具有高度运动性，能够穿透培养细胞。II型裂殖子较小（平均尺寸 = 5.9×0.9微米），呈纺锤形，细胞核位于中央，微线体较少，支链淀粉颗粒很少或没有，后端呈圆顶形，运动性较差，似乎无法穿透培养细胞。这两种裂殖子在牛艾美球虫的生命周期中可能具有截然不同的作用。
