肠艾美耳球虫(Eimeria intestinalis)内生发育阶段超微结构研究 Ⅰ.裂殖生殖阶段

Ultrastructural Studies on Endogenic Developmental Stages of Eimeria intestinalis Ⅰ.Schizogony Stages

肠艾美耳球虫共进行3代裂殖生殖,第一代在肠粘膜层的肠腺细胞内、第二和第三代在肠腺和肠粘膜层的细胞内进行。子孢子和各代裂殖子侵入细胞的途径不相同。裂殖体的核分裂为典型的球虫型有丝分裂。裂殖子以外出芽方式形成。每代裂殖体都有大型和小型两种,裂殖子亦相应的有细型和粗型之分。裂殖子为单核,少部分为双核或多核。裂殖子表面被有3层膜,有24根膜下微管。锥体为半截形圆锥,其前方有两个前极环。锥体腔内有两根棒状体的颈部、两根微线和两根微管向后延伸。大型裂殖体和小型裂殖体的比例在不同世代不同。

Three generations of schizogony occurred in E.intestinallis.During the en- dogenous cycle,the first schizogony occurred in the intestinal glands cells,the other two gen- erations occurred in the cells of the intestinal glands and the mucous membrane.It was dif- ferent that the entrance mechanism of sporozoites and three generations merozoites,the for- mation of merozoites was Exogensis.There were two types of meronts in each generation. the small type contained stumpy merozoites and the large type contained slender merozoites. Merozoite was enclosed with a trimembranous pellicle.There were 24 microtubules under in- ner pellicular complex.The conoid had the shape of a truncated cone,and was contructed by winding of microtubules.The merozoites possessed two rhoptries and a lot of micronemes. Proportion of large meronts and small meronts in various generations was different.The first generation meronts were mostly small,then.the change of proportion took place,and large meronts increased,the third generation mreozoites were mostly large.