Commitment of Mitotic Cells to Meiosis during the G_2 Phase of Premeiosis

概要

論文の詳細を見る
In the developing anther, archesporial cells that proliferate by mitotic division are converted into meiotic cells during the premeiotic interphase. Experiments with explanted microsporocytes of Lilium and Trillium were made to obtain evidence for the conversion of mitotic to meiotic cells during the premeiotic period. Explanted premeiotic cells were cultured through the division cycle at relatively high division frequencies and showed a variety of division types with respect to chromosomal events. The type of division depended on the premeiotic stage at which the cells were explanted. Cells in the G_1, S and early G_2 phases underwent mitotic division and formed a diad or binucleate monad. Cells explanted at the late G_2 phase were cultured throughout the normal meiotic cycle, which resulted in typical tetrad configuration. In microsporocytes explanted during the main part of the G_2 interval, centromere behavior was meiotic, but chromosome pairing and chiasma formation were disturbed. Thus, the G_2 interval was shown to be critical for the commitment of mitotic. cells to meiotic division. Detailed analysis showed that the intracellular changes that commit the cells to meiosis begin shortly after completion of premeiotic DNA synthesis and that these changes are progressive and cumulative.
日本植物生理学会の論文