Planta

, Volume 232, Issue 2, pp 287–298

Membrane fusion process and assembly of cell wall during cytokinesis in the brown alga, Silvetia babingtonii (Fucales, Phaeophyceae)

Authors

    • Muroran Marine Station, Field Science Center for Northern BiosphereHokkaido University
  • Akira Inoue
    • Graduate School of Fisheries ScienceHokkaido University
  • Masashi Mizuno
    • Graduate School of Agricultural ScienceKobe University
  • Kazuki Kanazawa
    • Graduate School of Agricultural ScienceKobe University
  • Takao Ojima
    • Graduate School of Fisheries ScienceHokkaido University
  • Kazuo Okuda
    • Graduate School of Kuroshio ScienceKochi University
  • Taizo Motomura
    • Muroran Marine Station, Field Science Center for Northern BiosphereHokkaido University
Review

DOI: 10.1007/s00425-010-1188-8

Cite this article as:
Nagasato, C., Inoue, A., Mizuno, M. et al. Planta (2010) 232: 287. doi:10.1007/s00425-010-1188-8

Abstract

During cytokinesis in brown algal cells, Golgi-derived vesicles (GVs) and flat cisternae (FCs) are involved in building the new cell partition membrane. In this study, we followed the membrane fusion process in Silvetia babingtonii zygotes using electron microscopy together with rapid freezing and freeze substitution. After mitosis, many FCs were formed around endoplasmic reticulum clusters and these then spread toward the future cytokinetic plane. Actin depolymerization using latrunculin B prevented the appearance of the FCs. Fusion of GVs to FCs resulted in structures that were thicker and more elongated (EFCs; expanded flat cisternae). Some complicated membranous structures (MN; membranous network) were formed by interconnection of EFCs and following the arrival of additional GVs. The MN grew into membranous sacs (MSs) as gaps between the MNs disappeared. The MSs were observed in patches along the cytokinetic plane. Neighboring MSs were united to form the new cell partition membrane. An immunocytochemical analysis indicated that fucoidan was synthesized in Golgi bodies and transported by vesicles to the future cytokinetic plane, where the vesicles fused with the FCs. Alginate was not detected until the MS phase. Incubation of sections with cellulase-gold showed that the cellulose content of the new cross wall was not comparable to that of the parent cell wall.

Keywords

Brown algae Cell wall Cytokinesis Flat cisternae Golgi-derived vesicles

Abbreviations

EFC

Expanded flat cisterna

ER

Endoplasmic reticulum

FC

Flat cisterna

GV

Golgi-derived vesicle

LB

Latrunculin B

MN

Membranous network

MS

Membranous sac

MT

Microtubule

Copyright information

© Springer-Verlag 2010