Under the Phylum Dinoflagellates, the current classification
recognises ~ 550 genera and a total of 6000 described species that play a
prominent role in water ecology. Molecular clock and biogeochemical indices
indicate that the dinoflagellate lineage diverged ~650 Ma, and fossil traces of
thecate cells and of cysts/zygotes appeared during the Triassic. This review is
dedicated to the great protistologist Edouard Chatton (1883–1947), aimed to
highlight the originality and remarkable diversity of some dinoflagellate
protists through the lens of cell biology. Their fossilised traces date back to
more than 538 million years (Phanerozoic aeon). However, they may be much older
because acritarchs from the (Meso) Proterozoic era (1500 million years ago)
could be their most primitive ancestors. Here, several representative examples
of the various lifestyles of free-living (the autotrophic thecate Prorocentrum
micans Ehrenberg and the heterotrophic athecate Noctiluca scintillans McCartney
and other “pseudo-noctilucidae”, as well as the thecate Crypthecodinium cohnii
Biecheler) and of parasitic dinoflagellates (the mixotroph Syndinium Chatton)
are described. Then, the different dinoflagellate mitotic systems were compared
and reported observations on the eyespot (ocelloid), an organelle that is
present in the binucleated Glenodinium foliaceum Stein and in some Warnowiidae
dinoflagellates and can be considered an evolutionary marker. The diversity and
innovations observed in mitosis, meiosis, reproduction, sexuality, cell cycle,
locomotion, and nutrition allow everyone to affirm that dinoflagellates are
among the most innovative unicells in the Kingdom Protista. Further research
using the most advanced techniques in cell and molecular biology is still
necessary to try to solve these enigmas.
Author(s) Details
Marie-Odile
Soyer-Gobillard
CNRS-Sorbonne University, Oceanological Observatory, Laboratoire Arago,
F-66650 Banyuls-sur-Mer, France.
Please see the link:- https://doi.org/10.9734/bpi/mbrao/v6/6715
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