微小泰泽球虫大配子发育与受精的超微结构

ULTRASTRUCTURAL ASPECTS OF MACROOAMETOGENESIS AND FERTILIZATION IN Tyzzeria rarvula

采用纯种微小泰泽球虫卵囊,人工感染四日龄雏鹅,定时剖杀,取小肠组织进行超薄切片,在透射电镜下观察微小泰泽球虫大配子体的发育与大、小配子的受精过程。大配子体由第二代裂殖子转变而来,在带虫空泡内发育。早期大配子体细胞核的浅层和周围均有多膜空泡分布。在大配子体的表面观察到了正待逸出的电子半透明空泡。成囊颗粒Ⅰ和Ⅱ先后出现,两者在分布、结构、大小及功能上均有明显不同。受精发生在卵囊壁形成之前。小配子的核和鞭毛均进入大配子,随后,小配子的核进入大配子的细胞核。没有观察到小配子鞭毛进入大配子的细胞核。

The fine structural aspects of Macrocametogenesis and process of fertilization in Tyzzeria parvula were studied in tissue from the small intestine of infected young domestic geese via electron microscopy.Multi-membranous vesicles were present in both the nucleoplasm and cytoplasm of young macrogametocytes.It was observed that electron translucent vacuoles appeared to be ejected from the surface of the macrogametocytes. The wall forming bodies of type 1 (WF1) came irto view before the wall forming bodies of type 2(WF2). The WF1 was osmi-ophilic, and was smaller than tne WF2.WF1 and WF2 participated respectively in formation of the outer and inner layer of the oocyst wall. Fertilization of a macrogamete by a micro-gamete occurred prior to oocyst wall formation.Both the nucleus and the flagella of the mi-crogamete penetrated into the cytoplasm of macrogamete, but only the nucleus fused with the nucleus of macrogamete.