Home • Ostreococcus tauri RCC1115 v1.0
Ostreococcus tauri RCC1115
Ostreococcus tauri strain OTH95, photo courtesy of Hervé Moreau, Laboratoire Arago


Ostreococcus belongs to the Mamiellophyceae, an early-diverging class within the green plant lineage, and is reported as a globally abundant, single-celled alga thriving in the upper (illuminated) water column of the oceans. The most striking feature of O. tauri and related species is their minimal cellular organization: a naked, nearly 1-micron cell, lacking flagella, with a single chloroplast and mitochondrion.

While comparative genomics of Ostreococcus strains have unravelled four different species in this genus, O. tauri, O. lucimarinus, O. sp RCC809 and O. mediterraneus, the intra-specific level of diversity in these enigmatic organisms is yet unknown. Population genomics analysis will help to understand the role of standing genomic variation in environmental adaptation of these microorganisms.

This portal gives access to the genome of O. tauri RCC1115, obtained by combining PACBIO sequencing and high-coverage Illumina sequencing [1]. Strain RCC1115 encodes for the candidate ‘plus’ mating type loci, a 450kb lowGC region on chromosome 2, whereas strain RCC4221 encodes for the candidate ‘minus’ mating type in O. tauri [2].


[1] Population genomics of picophytoplankton unveils novel chromosome hypervariability. Blanc-Mathieu R, Krasovec M, Hebrard M, Yau S, Desgranges E, Martin J, Schackwitz W, Kuo A, Salin G, Donnadieu C, Desdevises Y, Sanchez-Ferandin S, Moreau H, Rivals E, Grigoriev IV, Grimsley N, Eyre-Walker A. and  Piganeau, G. Sci Adv. 2017 Jul 5;3(7):e1700239.
[2] An improved genome of the model marine alga Ostreococcus tauri unfolds by assessing Illumina de novo assemblies. Blanc-Mathieu R, Verhelst B, Derelle E, Rombauts S, Bouget FY, Carré I, Château A, Eyre-Walker A, Grimsley N, Moreau H, Piégu B, Rivals E, Schackwitz W, Van de Peer Y, Piganeau G. BMC Genomics. 2014 Dec 13;15:1103.
doi: 10.1186/1471-2164-15-1103.

Genome Reference(s)