源真核生物蓝氏贾第虫核分裂的初步观察

THE PRELIMINARY STUDY ON THE NUCLEAR DIVISION OF THE ARCHEZOAN, Giardia lamblia

贾第虫属于源真核生物（Ａｒｃｈｅｚｏａ）中的双滴虫门，是目前所知的最低等的真核生物。本工作首次对蓝氏贾第虫（Ｇｉａｒｄｌｉａｌａｍｂｌａ）的核分裂作了初步的电镜观察，未能在分裂着的核中见到纺锤体或纺锤体微管。以０．１—２０μｇ／ｍｌ浓度的秋水仙素作实验，其核分裂也不受阻抑。以抗微管蛋白的多抗作免疫荧光检查，也未见分裂着的核中有微管蛋白。这似乎意味着其核分裂方式乃是前有丝分裂性质的。对此进行了讨论。

Diplomonads seem to be the most primitive archezoa. In literature, almost all thg studies on diplomonad nuclear division were accomplished under light microscope, Considerring the primitiveness of diplomonad nucleus, we investigated the nuclear division of cultivated Giardia lamblia with routine electron-microscopy preliminarily. Nuclear envelope was found to be preseved during the whole division process. Spindle or spindle microtubules were never found within dividing nucleus or cytoplasm. No condensed metaphase chromosomes were observed, although heterochromatin could occationally be seen both in dividing nucleus and in interphase nucleus.If there is surely no spinde participating the division process, then colchcine should have no influence on this process. Our experiments showed that various concentrations of colchicine (0.1-20μg / ml), certainly had no effect on the cell division of Giardia.Immuno-fluorescent microscopical detection was done with anti-tubulin antibody and it was found that no tubulin or tubulin-made structure existed in the interphase nucleus and dividing nucleus, while cytoplasm and flagella gave strong positive reaction.The resuts described above suggested that there is no spindle formed during the nuclear division of Giardia. The possible significance of this phenomenon in the origin and evolution of mitosis was discussed.