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Abstract

The chloroplasts of dinoflagellates display an unusually
high diversity. Therefore, besides the typical peridinincontaining
chloroplast probably of red algal origin
(Ishida & Green 2002), some dinoflagellate chloroplasts
have originated from a cryptomonad, diatom,
haptophyte or chlorophyte (Watanabe et al. 1987,
1990; Elbrächter & Schnepf 1996; Chesnick et al.
1997; Schnepf & Elbrächter 1999; Takishita et al.
1999; Hackett et al. 2003). It has recently been
hypothesized that the seeming readiness of dinoflagellates
to take up and incorporate foreign chloroplasts
might rely on the exceptionally high number of chloroplast
genes transferred to the dinoflagellate nucleus
from the original chloroplast (Green 2004). As acquisition
of chloroplast-containing endosymbionts seems
to be a relatively frequent event in apparently diverse
groups of dinoflagellates, the chloroplast type and color
have not been considered to be useful taxonomic criteria
above species level (Elbrächter & Schnepf 1996).
However, recent investigations based on molecular
sequences have quite surprisingly shown that the diatom-
containing dinoflagellates form a monophyletic
group (Inagaki et al. 2000; Horiguchi 2003; Tamura
et al. 2005; Horiguchi & Takano 2006), irrespective of
the fact that this group consists of morphologically very
diverse species (e.g. athecate, thecate, flagellate, coccoid
and filamentous forms). This indicates that the
acquisition of endosymbionts might not be so frequent
a phenomenon as hitherto anticipated and that chloroplast
type might be a taxonomic criterion to be used
also at higher than species level.

Item Type:	Article
Authors/Creators:	Hansen, G and Botes, L and de Salas, MF
Keywords:	dinoflagellates, endosymbiosis, Lepidodinium viride, nuclear pores, phylogeny, ultrastructure
Journal or Publication Title:	Phycological Research
Publisher:	Australia
ISSN:	1322-0829
DOI / ID Number:	10.1111/j.1440-1835.2006.00442.x
Additional Information:	The definitive version is available at www.blackwell-synergy.com
Item Statistics:	View statistics for this item

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