毁灭泰泽球虫内生发育的超微结构研究 Ⅲ.小配子生殖与小配子

UlTRASTRUCTURAL STUDIES ON THE ENDOGENOUS DEVELOPMENT OF TYZZERIA PERNICIOSA, A COCCIDIAN PARASITE OF PEKIN DUCK 3. MICROGAMETOGENESIS AND THE MICROGAMETE

毁灭泰泽球虫的小配子生殖发生在小肠上皮细胞内由单层膜围成的带虫空泡中。其细胞核的分裂过程与裂殖生殖时期的相似,但小配子体的细胞核缺少核仁,染色质在核的浅层聚集成致密的斑块。在小配子的形成过程中,核附近的中心粒转变为基粒,其中央微管消失。随后,两根鞭毛从基粒长出,突入带虫空泡。细胞核的致密部分逐渐地进入小配子体的表面突起,并最终发育为小配子的细胞核;而核的疏浅部分则留在小配子体的细胞质中,成为残体的成份。成熟的小配子拥有两根纤长的鞭毛和香蕉形的身体,体内含有长形的细胞核及在其尖端嵌入的线粒体,一组微管(4+1+1)自基粒附近向体后延伸,但仅约3根微管抵达身体的末端。

The microgametogenesis occurred within the parasitophorous vacuo-les enclosed by a unit membrane in the epithelial cells of the small in testine. The process of nuclear division was similar to that of she schi zogony, but the nucleus of microgametocyte lacked a nucleolus and the chromatin clumpped into dense patches at the periphery. During the formation of the microgametes,the two centrioles at each nucleus appeared to be transformed into basal bodies and the central microtubule disappeared, and then the two flagella grew up from basal bodies and protruded gradually into the parasitophorous vacuole The. electron dense portions of the nuclei got into the protrusions of the surface of microgametocyte and finally became the nuclei of microgametes, while the light portions remained in the proper cytoplasm lof the microgametocyle as the residua. The mature microgamete possessed two long flagella and the banana-shaped body, in which an elongated nucleus overlapped a mitochondrion near the anterior. A group of microtubules ( 4 + 1 + 1 ) ran longitudinally from the basal body region to the posterior, but about 3 of which reached the posterior tip.