1969 年 34 巻 4 号 p. 593-604
The process of spindle fiber formation in pollen mother cells of Trillium kamtschaticum, was studied by electron microscopy.
Initially, the spindle fibers appear as a mass of microtubules (about 25mμ in diameter) in the diakinetic cell (Figs. 10-12). This mass in the pollen mother cells seems to be restricted to the regions which correspond to the polar regions in later stages. The mass of microtubules enlarges during diakinesis. Later, after the fragmentation of nuclear envelope, the microtubules in the mass strech to the chromosomes in the nuclear area with tubular ER. Some of microtubules seem to connect with the kinetochor of each chromosome and form chromosomal fibers.
The possibility of the mixing nuclear materials with cytoplasmic ones is discussed.