Unusual Features of Dinokaryon, the Enigmatic Nucleus of Dinoflagellates

Fukuda, Yasuhiro; Suzaki, Toshinobu

doi:10.1007/978-4-431-55130-0_2

Cited by 8 publications

(17 citation statements)

References 94 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…More than 4500 species have been documented, among which nearly 4000 species are free living (class Dinophycea) whereas 40 are intracellular parasites (class Syndinea) [2]. Approximately 50% of dinoflagellates are photosynthetic [3], in addition to heterotrophic and mixotrophic type, and is one of the most important primary producers in marine and freshwater ecosystems. Symbiotic dinoflagellates, such as Symbiodinium , are essential for the formation of reef ecosystems whereas toxic dinoflagellate species produce harmful algal blooms (HABs) [4].…”

Section: An Overview Of Dinoflagellatesmentioning

confidence: 99%

“…Dinoflagellates possess a number of unusual features, e.g., unique plastids acquired from red algae via endosymbiosis [3,13,14], mitochondrial genomes encoding three proteins for the electron transport chain, and fragmented genes for rRNA [15,16]. It is also commonly accepted that the nuclei of dinoflagellates are particularly unusual.…”

Section: An Overview Of Dinoflagellatesmentioning

confidence: 99%

See 1 more Smart Citation

Distinctive Nuclear Features of Dinoflagellates with A Particular Focus on Histone and Histone-Replacement Proteins

et al. 2018

View full text Add to dashboard Cite

Dinoflagellates are important eukaryotic microorganisms that play critical roles as producers and grazers, and cause harmful algal blooms. The unusual nuclei of dinoflagellates “dinokaryon” have led researchers to investigate their enigmatic nuclear features. Their nuclei are unusual in terms of their permanently condensed nucleosome-less chromatin, immense genome, low protein to DNA ratio, guanine-cytosine rich methylated DNA, and unique mitosis process. Furthermore, dinoflagellates are the only known group of eukaryotes that apparently lack histone proteins. Over the course of evolution, dinoflagellates have recruited other proteins, e.g., histone-like proteins (HLPs), from bacteria and dinoflagellates/viral nucleoproteins (DVNPs) from viruses as histone substitutes. Expression diversity of these nucleoproteins has greatly influenced the chromatin structure and gene expression regulation in dinoflagellates. Histone replacement proteins (HLPs and DVNPs) are hypothesized to perform a few similar roles as histone proteins do in other eukaryotes, i.e., gene expression regulation and repairing DNA. However, their role in bulk packaging of DNA is not significant as low amounts of proteins are associated with the gigantic genome. This review intends to summarize the discoveries encompassing unique nuclear features of dinoflagellates, particularly focusing on histone and histone replacement proteins. In addition, a comprehensive view of the evolution of dinoflagellate nuclei is presented.

show abstract

Section: An Overview Of Dinoflagellatesmentioning

confidence: 99%

Section: An Overview Of Dinoflagellatesmentioning

confidence: 99%

Distinctive Nuclear Features of Dinoflagellates with A Particular Focus on Histone and Histone-Replacement Proteins

et al. 2018

View full text Add to dashboard Cite

show abstract

“…They are thicker than the 2-nm DNA molecule, but thinner than the typical eukaryotic 11-nm nucleosome fibers, and do not demonstrate the "beads-onstring" organization. The smooth chromatin fiber is considered as the first level of DNA packaging in the absence of 11-nm fiber in the dinoflagellates (Fukuda and Suzaki, 2015). Several models explaining smooth fiber packaging and chromosome architecture have been proposed for these protists.…”

Section: Introductionmentioning

confidence: 99%

“…Some researchers favor the cholesteric liquid crystal model proposed by Bouligand and Livolant (Bouligand et al, 1968;Rill et al, 1989). In spite of the latter model is being considered the most probable one, the question of how the chromatin in the dinoflagellate nucleus is organized remains unanswered (Fukuda and Suzaki, 2015).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Ultrastructural organization of the chromatin elements in chromosomes of the dinoflagellate Prorocentrum minimum

Golyshev¹,

Berdieva²,

Musinova³

et al. 2018

Protistology

View full text Add to dashboard Cite

DNA of the majority of present-day eukaryotes is folded with the aid of highly conserved histone proteins to form nucleosome fibers, which further condense via interactions with histones and non-histone chromatin proteins. Dinoflagellate chromatin is unique among eukaryotes, as their chromosomes lack the histones and remain condensed throughout the cell cycle. Here, we report the results of electron microscopy study of chromatin elements inside the chromosomes of potentially toxic planktonic dinoflagellate Prorocentrum minimum. We found that chromatin fibers inside the condensed chromosomes of P. minimum form not only arch-like structures, that were repeatedly described for various dinoflagellate species, but also rosette-like complexes with chromatin fibers radiating from its electron-dense center. The effects of histone loss in the evolution of dinoflagellates are discussed within the frames of the hierarchical chromatin folding paradigm.

show abstract

Algae from Secondary Endosymbiosis

Friedl

2024

Biology of Algae, Lichens and Bryophytes

View full text Add to dashboard Cite

Unusual Features of Dinokaryon, the Enigmatic Nucleus of Dinoflagellates

Cited by 8 publications

References 94 publications

Distinctive Nuclear Features of Dinoflagellates with A Particular Focus on Histone and Histone-Replacement Proteins

Distinctive Nuclear Features of Dinoflagellates with A Particular Focus on Histone and Histone-Replacement Proteins

Ultrastructural organization of the chromatin elements in chromosomes of the dinoflagellate Prorocentrum minimum

Algae from Secondary Endosymbiosis

Contact Info

Product

Resources

About