These authors contributed equally to this work.
Appearance of actin microfilament ‘twin peaks’ in mitosis and their function in cell plate formation, as visualized in tobacco BY-2 cells expressing GFP–fimbrin
Article first published online: 14 OCT 2005
The Plant Journal
Volume 44, Issue 4, pages 595–605, November 2005
How to Cite
Sano, T., Higaki, T., Oda, Y., Hayashi, T. and Hasezawa, S. (2005), Appearance of actin microfilament ‘twin peaks’ in mitosis and their function in cell plate formation, as visualized in tobacco BY-2 cells expressing GFP–fimbrin. The Plant Journal, 44: 595–605. doi: 10.1111/j.1365-313X.2005.02558.x
- Issue published online: 14 OCT 2005
- Article first published online: 14 OCT 2005
- Received 8 July 2005; revised 10 August 2005; accepted 15 August 2005.
- green fluorescent protein;
- tobacco BY-2 cell;
- cell cycle;
The actin cytoskeleton of higher plants plays an essential role in plant morphogenesis and in maintaining various cellular activities. In this study we established a tobacco BY-2 cell line, stably transformed with a GFP–fimbrin actin-binding domain (ABD) 2 construct, that allows visualization of actin microfilaments (MFs) in living cells. Using this cell line, designated BY-GF11, we performed time-sequential observations of MF dynamics during cell-cycle progression. Detailed analyses revealed the appearance of a broad MF band in the late G2 phase that separated to form a structure corresponding to the so-called actin-depleted zone (ADZ) in mitosis. In BY-GF11, the MF structure at the cell cortex in mitosis appeared to form two bands rather than the ADZ. Measurements of fluorescent intensities of the cell cortex indicated an MF distribution that resembled two peaks, and we therefore named the structure MF ‘twin peaks’ (MFTP). The cell plate formed exactly within the valley between the MFTP at cytokinesis, and this cell-plate guidance was distorted by disruption of the MFTP by an inhibitor of actin polymerization. These results suggest that the MFTP originates from the broad MF band in the G2 phase and functions as a marker of cytokinesis.