Pr. Fobert et al., PATTERNS OF CELL-DIVISION REVEALED BY TRANSCRIPTIONAL REGULATION OF GENES DURING THE CELL-CYCLE IN PLANTS, EMBO journal, 13(3), 1994, pp. 616-624
Transcripts from five cell cycle related genes accumulate in isolated
cells dispersed throughout the actively dividing regions of plant meri
stems. We propose that this pattern reflects gene expression during pa
rticular phases of the cell division cycle. The high proportion of iso
lated cells suggests that synchrony between daughter cells is rapidly
lost following mitosis. This is the first time that such a cell specif
ic expression pattern has been described in a higher organism. Counter
staining with a DNA specific dye revealed that transcripts from three
genes (two mitotic cyclins and a cdc2-like gene) accumulate during par
t of interphase and early mitosis whereas transcripts from a histone H
4 gene are preferentially detected only in interphase cells. Double la
belling for cyclin and histone H4 transcripts confirms that these gene
s are expressed in different cells, and therefore at different phases
of the cell cycle. The results suggest that transcriptional regulation
of cell cycle related genes may be important in controlling cell divi
sion in plants, and that these genes are useful markers for identifyin
g cells at specific phases of the cell cycle within plant meristems.