Ostreococcus (lat.) Is a genus of unicellular coccoid green algae that are part of the Mamiellophyceae class . They are part of picoplankton , which plays a key role in the ocean carbon cycle . This genus includes the smallest free-living eukaryotes , reaching a size of only 0.8 microns .
| Ostreococcus | |||||||||||||||||
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Ostreococcus Courties & Chrét.-Din. | |||||||||||||||||
Study History
The first known species of the genus, Ostreococcus tauri , was described in 1994 when studying picoplankton from Lake To using flow cytometry [1] . It is convenient to study unicellular photosynthetic organisms using flow cytometry due to chlorophyll and other fluorophores used to absorb sunlight [2] . The newly described species was assigned to the class Prasinophyceae based on the composition of chlorophylls and carotenoids [1] , as well as the ultrastructure of cells. Subsequently, the position of the species was confirmed by analysis of 18S rRNA [3] . Molecular phylogenetic data obtained in the study of 18S rRNA allowed us to distinguish a new class, Mamiellophyceae , which included species of Ostreococcus in the Bathycoccaceae family [4] . Mamiellophyceae is one of the most environmentally successful eukaryotic groups that make up marine and possibly freshwater photosynthetic picoplankton. Metagenomic analysis [5] and metabarcoding [6] made it possible to detect Ostreococcus in various parts of the world's oceans.
Description
The genus Ostreococcus contains the smallest known free-living eukaryotes, since the size of most cells does not exceed 0.8 μm [1] . The ultrastructure of the cells is simple: these are coccoid cells devoid of the cell wall and containing one chloroplast , one mitochondria , one Golgi apparatus , and also the nucleus [1] . The genomes of Ostreococcus are very small [7] . Genomic sequences are known for three species of the genus: O. tauri RCC422 (size 13 megabytes (Mb), the genome was sequenced in 2006 [8] and the data were updated in 2014 [9] ), O. lucimarinus CCMP2514 [10] and strain RCC809 [11] . The GC composition of these algae is higher than that of higher plants , however, two unusual chromosomes are characterized by a low GC composition and carry many transposons and genes of prokaryotic origin [7] . Viruses that infect members of the genus Ostreococcus are known , but some lines develop resistance to them. Resistance can be caused by almost half of the genes of the unusual chromosome 19, which, as a comparison of karyotypes shows, has undergone physical rearrangements [7] . In 2012, using the KEGG database , maps of metabolic pathways for these two species of the genus were reconstructed [12] .
Ecology
Ostreococcus species are distributed all over the globe in the photic zone of the oceans , where they fix carbon dioxide and release oxygen , thus being producers [7] .
Classification
According to the database of , as of January 2017, 2 genera are included in the genus [13] :
- Ostreococcus mediterraneus B. Marin & NHGrimsley [14]
- Ostreococcus tauri C. Courties & M.-J.Chrétiennot-Dinet
According to other sources, another species is distinguished - Ostreococcus lucimarinus [10] , as well as at least one strain that does not belong to any of the species listed above - Ostreococcus sp. RCC809 [11] .
Notes
- ↑ 1 2 3 4 Courties Claude , Vaquer André , Troussellier Marc , Lautier Jacques , Chrétiennot-Dinet Marie J. , Neveux Jacques , Machado Cordelia , Claustre Hervé. Smallest eukaryotic organism (Eng.) // Nature. - 1994 .-- July ( vol. 370 , no. 6487 ). - P. 255-255 . - ISSN 0028-0836 . - DOI : 10.1038 / 370255a0 .
- ↑ Davey HM , Kell DB Flow cytometry and cell sorting of heterogeneous microbial populations: the importance of single-cell analyses. (English) // Microbiological reviews. - 1996. - Vol. 60, no. 4 . - P. 641-696. - PMID 8987359 .
- ↑ Courties Claude , Perasso Roland , Chrétiennot-Dinet Marie-Josèphe , Gouy Manolo , Guillou Laure , Troussellier Marc. PHYLOGENETIC ANALYSIS AND GENOME SIZE OF OSTREOCOCCUS TAURI (CHLOROPHYTA, PRASINOPHYCEAE) // Journal of Phycology. - 1998. - October ( t. 34 , No. 5 ). - S. 844-849 . - ISSN 0022-3646 . - DOI : 10.1046 / j.1529-8817.1998.340844.x .
- ↑ Marin Birger , Melkonian Michael. Molecular Phylogeny and Classification of the Mamiellophyceae class. nov. (Chlorophyta) based on Sequence Comparisons of the Nuclear- and Plastid-encoded rRNA Operons // Protist. - 2010. - April ( t. 161 , No. 2 ). - S. 304—336 . - ISSN 1434-4610 . - DOI : 10.1016 / j.protis.2009.10.002 .
- ↑ Piganeau Gwenaël , Moreau Hervé. Screening the Sargasso Sea metagenome for data to investigate genome evolution in Ostreococcus (Prasinophyceae, Chlorophyta) (Eng.) // Gene. - 2007 .-- December ( vol. 406 , no. 1-2 ). - P. 184-190 . - ISSN 0378-1119 . - DOI : 10.1016 / j.gene.2007.09.09.015 .
- ↑ Demir-Hilton Elif , Sudek Sebastian , Cuvelier Marie L , Gentemann Chelle L , Zehr Jonathan P , Worden Alexandra Z. Global distribution patterns of distinct clades of the photosynthetic picoeukaryote Ostreococcus // The ISME Journal. - 2011. - February 3 ( t. 5 , No. 7 ). - S. 1095-1107 . - ISSN 1751-7362 . - DOI : 10.1038 / ismej.2010.209 .
- ↑ 1 2 3 4 Yau S. , Hemon C. , Derelle E. , Moreau H. , Piganeau G. , Grimsley N. A Viral Immunity Chromosome in the Marine Picoeukaryote, Ostreococcus tauri. (English) // PLoS pathogens. - 2016. - Vol. 12, no. 10 . - P. e1005965. - DOI : 10.1371 / journal.ppat.1005965 . - PMID 27788272 .
- ↑ Derelle E. , Ferraz C. , Rombauts S. , Rouze P. , Worden AZ , Robbens S. , Partensky F. , Degroeve S. , Echeynie S. , Cooke R. , Saeys Y. , Wuyts J. , Jabbari K . , Bowler C. , Panaud O. , Piegu B. , Ball SG , Ral J.-P. , Bouget F.-Y. , Piganeau G. , De Baets B. , Picard A. , Delseny M. , Demaille J. , Van de Peer Y. , Moreau H. Genome analysis of the smallest free-living eukaryote Ostreococcus tauri unveils many unique features // Proceedings of the National Academy of Sciences. - 2006 .-- 25 July ( vol. 103 , no. 31 ). - P. 11647-11652 . - ISSN 0027-8424 . - DOI : 10.1073 / pnas.0604795103 .
- ↑ Blanc-Mathieu Romain , Verhelst Bram , Derelle Evelyne , Rombauts Stephane , Bouget François-Yves , Carré Isabelle , Château Annie , Eyre-Walker Adam , Grimsley Nigel , Moreau Hervé , Piégu Benoit , Rivals Eric , Schackwitz , Piganeau Gwenaël. An improved genome of the model marine alga Ostreococcus tauri unfolds by assessing Illumina de novo assemblies (English) // BMC Genomics. - 2014 .-- Vol. 15 , no. 1 . - P. 1103 . - ISSN 1471-2164 . - DOI : 10.1186 / 1471-2164-15-1103 .
- ↑ 1 2 Palenik B. , Grimwood J. , Aerts A. , Rouze P. , Salamov A. , Putnam N. , Dupont C. , Jorgensen R. , Derelle E. , Rombauts S. , Zhou K. , Otillar R. , Merchant SS , Podell S. , Gaasterland T. , Napoli C. , Gendler K. , Manuell A. , Tai V. , Vallon O. , Piganeau G. , Jancek S. , Heijde M. , Jabbari K. , Bowler C . , Lohr M. , Robbens S. , Werner G. , Dubchak I. , Pazour GJ , Ren Q. , Paulsen I. , Delwiche C. , Schmutz J. , Rokhsar D. , Van de Peer Y. , Moreau H. , Grigoriev IV The tiny eukaryote Ostreococcus provides genomic insights into the paradox of plankton speciation // Proceedings of the National Academy of Sciences. - 2007 .-- 25 April ( vol. 104 , no. 18 ). - P. 7705-7710 . - ISSN 0027-8424 . - DOI : 10.1073 / pnas.0611046104 .
- ↑ 1 2 Ostreococcus .
- ↑ Krumholz Elias W. , Yang Hong , Weisenhorn Pamela , Henry Christopher S. , Libourel Igor GL Genome-wide metabolic network reconstruction of the picoalga Ostreococcus // Journal of Experimental Botany. - 2011. - December 29 ( t. 63 , No. 6 ). - S. 2353-2362 . - ISSN 1460-2431 . - DOI : 10.1093 / jxb / err407 .
- ↑ Ostreococcus (English) . AlgaeBase: Taxonomy Browser . (Retrieved February 3, 2017) .
- ↑ Subirana Lucie , Péquin Bérangère , Michely Stéphanie , Escande Marie-Line , Meilland Julie , Derelle Evelyne , Marin Birger , Piganeau Gwenaël , Desdevises Yves , Moreau Hervé , Grimsley Nigel H. Morphology, Genome Plasticyocal the Phylococcus Genome Cryptic Species, O. mediterraneus sp. nov. (Mamiellales, Mamiellophyceae) (Eng.) // Protist. - 2013 .-- September ( vol. 164 , no. 5 ). - P. 643-659 . - ISSN 1434-4610 . - DOI : 10.1016 / j.protis.2013.06.002 .
Links
- Genus Ostreococcus (English) in the World Register of Marine Species . (Retrieved February 3, 2017) .