Author for correspondence: e-mail email@example.com.
EFFECT OF LATRUNCULIN B AND BREFELDIN A ON CYTOKINESIS IN THE BROWN ALGA SCYTOSIPHON LOMENTARIA (SCYTOSIPHONALES, PHAEOPHYCEAE)1
Article first published online: 26 MAR 2009
© 2009 Phycological Society of America
Journal of Phycology
Volume 45, Issue 2, pages 404–412, April 2009
How to Cite
Nagasato, C. and Motomura, T. (2009), EFFECT OF LATRUNCULIN B AND BREFELDIN A ON CYTOKINESIS IN THE BROWN ALGA SCYTOSIPHON LOMENTARIA (SCYTOSIPHONALES, PHAEOPHYCEAE). Journal of Phycology, 45: 404–412. doi: 10.1111/j.1529-8817.2009.00655.x
Received 22 January 2008. Accepted 13 October 2008.
- Issue published online: 6 APR 2009
- Article first published online: 26 MAR 2009
- brefeldin A;
- brown algae;
- Golgi bodies;
- latrunculin B;
- Scytosiphon lomentaria
In zygotes of the brown alga Scytosiphon lomentaria (Lyngb.) Link, cytokinesis proceeds by growth of membranous sacs, which are formed by fusion of Golgi vesicles and flat cisternae accumulated at the future cytokinetic plane. It has been reported that depolymerization of actin filaments by latrunculin B does not inhibit mitosis. However, this molecule prevents the formation of the actin plate, which appears at the region of intermingled microtubules from each centrosome just before and during cytokinesis. In this study, zygotes treated with latrunculin B were observed using EM. Remarkably, this reagent inhibited the formation of flat cisternae. Golgi vesicles gathered around the midzone between the two daughter nuclei and fused with the plasma membrane there. As a result, the plasma membrane invaginated, in a complicated manner, into the cytoplasm. However, these invaginations of the plasma membrane never produced a continuous partition membrane. The ultrastructure of zygotes treated with brefeldin A, which prevents Golgi-mediated secretion, was also examined. Flat cisternae appeared at the future cytokinetic plane, and a new cell partition membrane was formed. However, the partition membrane became thick, because it was filled with amorphous material rather than the normal rigid fibrous material. These results suggested that actin is involved in the formation of flat cisternae, where it is necessary for completion of the new cell partition membrane, and that Golgi vesicles may play an important role in the deposition of cell wall material.