268 J.M. Seguí-Simarro et al.
Fig. 7 DRP rings and spirals. Tomographic sliceAand modelA′of a spiral in an
extended conformation, around the thin tubule that connects two vesicular cell plate
domains.BTomographic model of a tubulo-vesicular cell plate (solid phragmoplast
stage) of Arabidopsis somatic cells showing several compacted rings around thin tubules.
CImmunogold labeling with anti-DRP1A antibodies decorating a tubulo-vesicular so-
matic cell plate. Note that particles are mainly present at the narrow regions (likely
tubules) of the cell plate. Thescale barsrepresents 100 nm
ies against AtDRP1a (ADL1a), a dynamin-related protein that is present in
Arabidopsisendosperm (Otegui et al. 2001) and meristem cells (Fig. 7C). Two
GTP-binding, dynamin-related proteins (DRPs), phragmoplastin and DRP1a,
have been identified in cell plates, and especially in the growing regions of the
cell plates of both soybean andArabidopsis(Gu and Verma 1996; Kang et al.
2001, 2003; Verma 2001). None of the adl1 mutants produced to date have
shown any impairment in cytokinesis, most likely due to gene redundancy
(Bednarek and Falbel 2002; Konopka et al. 2006).