open access

https://hdl.handle.net/2115/61930

Kleptochloroplast Enlargement, Karyoklepty and the Distribution of the Cryptomonad Nucleus in Nusuttodinium (= Gymnodinium) aeruginosum (Dinophyceae)

英語

ultrastructure

2015-05

Elsevier

Protist

166(2)

177-195

The unarmoured freshwater dinoflagellate Nusuttodinium (= Gymnodinium) aeruginosum retains a cryptomonad-derived kleptochloroplast and nucleus, the former of which fills the bulk of its cell volume. The paucity of studies following morphological changes to the kleptochloroplast with time make it unclear how the kleptochloroplast enlarges and why the cell ultimately loses the cryptomonad nucleus. We observed, both at the light and electron microscope level, morphological changes to the kleptochloroplast incurred by the enlargement process under culture conditions. The distribution of the cryptomonad nucleus after host cell division was also investigated. The volume of the kleptochloroplast increased more than 20-fold, within 120 h of ingestion of the cryptomonad. Host cell division was not preceded by cryptomonad karyokinesis so that only one of the daughter cells inherited a cryptomonad nucleus. The fate of all daughter cells originating from a single cell through five generations was closely monitored, and this observation revealed that the cell that inherited the cryptomonad nucleus consistently possessed the largest kleptochloroplast for that generation. Therefore, this study suggests that some important cryptomonad nucleus division mechanism is lost during ingestion process, and that the cryptomonad nucleus carries important information for the enlargement of the kleptochloroplast.

学術雑誌論文

Accepted Manuscript

Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International

(C) 2015, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/

1434-4610