@booklet {dennu_biological_2023,
	title = {Biological and genomic resources for the cosmopolitan phytoplankton Bathycoccus: Insights into genetic diversity and major structural variations},
	year = {2023},
	note = {Pages: 2023.10.16.562038 Section: New Results},
	month = {oct},
	publisher = {bioRxiv},
	abstract = {Population-scale sequencing has become a standard practice to explore the natural genetic diversity underlying adaptation, notably in land plants. However, current sequencing initiatives for eukaryotic phytoplankton primarily concentrate on creating reference genomes for model organisms and characterizing natural communities through metagenomics approaches. Consequently, few species have been thoroughly sequenced and intraspecific genetic diversity remains virtually undescribed, limiting our understanding of diversity and adaptation mechanisms. Here we report a biological and genomic resource to explore the genetic diversity of the cosmopolitan and ecologically important Bathycoccus genus. To span broad geographical and temporal scales, we selected available strains but also isolated and genotyped strains from both the Banyuls bay (Mediterranean sea) and the Baffin bay (Arctic ocean). By combining ONT long reads and Illumina short reads technologies, we produced and annotated 28 Bathycoccus sp. de novo assembled genomes of high quality, including 24 genomes of Bathycoccus prasinos strains along a latitudinal gradient between 40{\textdegree} and 78{\textdegree} North, one reference genome of the Bathycoccus calidus species and 3 genomes of a yet undescribed Bathycoccus species named Bathycoccus catiminus. We assessed the genetic diversity of this genus through phylogenomic analyses and highlighted the central role of this genomic resource in providing new insights into the diversity of outlier chromosomal structures. The Bathycoccus biological and genomic resources offer a robust framework for investigating the diversity and adaptation mechanisms of eukaryotic phytoplankton in the Ocean. Significance statement Comparative and functional approaches for the study of eukaryotic phytoplankton and their adaptation to latitudes and seasons that rely on extensive biological and genomic resources are currently lacking. Here we report such resources and describe the natural diversity of the cosmopolitan phytoplankton Bathycoccus, providing insights into its species and intraspecific diversity and establishing it as a robust model for functional and ecological studies.},
	keywords = {RCC1615, RCC1868, RCC4222, RCC4752, RCC5417, RCC685, RCC716},
	doi = {10.1101/2023.10.16.562038},
	url = {https://www.biorxiv.org/content/10.1101/2023.10.16.562038v1},
	author = {Dennu, Louis and Devic, Martine and Rigonato, Janaina and Falciatore, Angela and Lozano, Jean-Claude and Verg{\'e}, Val{\'e}rie and Mariac, C{\'e}dric and Jaillon, Olivier and Team, The Dark Edge genomics sampling and Sabot, Fran{\c c}ois and Bouget, Fran{\c c}ois-Yves}
}
@article {sands_genetic_2023,
	title = {Genetic and physiological responses to light quality in a deep ocean ecotype of Ostreococcus, an ecologically important photosynthetic picoeukaryote},
	journal = {Journal of Experimental Botany},
	year = {2023},
	pages = {erad347},
	abstract = {Abstract Phytoplankton are exposed to dramatic variations in light quality when cells are carried by upwelling or downwelling currents or encounter sediment. We investigated the potential impact of light quality changes in Ostreococcus, a key marine photosynthetic picoeukaryote, by analysing changes in its transcriptome, pigment content and photophysiology after acclimation to monochromatic red, green or blue light. The clade B species RCC809, isolated from the deep euphotic zone of the tropical Atlantic Ocean, responded to blue light by accelerating cell division at the expense of storage reserves and by increasing the relative level of blue-light absorbing pigments. RCC809 responded to red and green light by increasing its potential for photoprotection. In contrast, the clade A species OTTH0595, which originates from a shallow water environment, showed no difference in photosynthetic properties and minor differences in carotenoid contents between light qualities. This was associated with the loss of candidate lightquality responsive promoter motifs identified in RCC809 genes. These results demonstrate that light quality can have a major influence on the physiology of eukaryotic phytoplankton and suggest that different light quality environments can drive selection for diverse patterns of responsiveness and environmental niche partitioning.},
	keywords = {Rcc141, RCC4221, RCC745, RCC809},
	issn = {0022-0957, 1460-2431},
	doi = {10.1093/jxb/erad347},
	url = {https://academic.oup.com/jxb/advance-article/doi/10.1093/jxb/erad347/7258950},
	author = {Sands, Elizabeth and Davies, Sian and Puxty, Richard John and Verg{\'e}, Val{\'e}rie and Bouget, Fran{\c c}ois-Yves and Scanlan, David John and Carr{\'e}, Isabelle Alice}
}
@booklet {devic_indel_2023,
	title = {An INDEL genomic approach to explore population diversity of phytoplankton : \textit{Bathycoccus , a case study},
	year = {2023},
	publisher = {Ecology},
	type = {preprint},
	abstract = {Abstract Although metabarcoding has generated large dataset on world-wide phytoplankton species diversity, little is known about the intraspecies diversity underlying adaptation to environmental niches. To gain insight into population diversity, a novel INDEL based method was developed on Bathycoccus prasinos . Oxford Nanopore Technology (ONT) sequencing was first used to characterise structural variants (SV) among the genomes of Bathycoccus sampled from geographically distinct regions in the world ocean. Markers derived from INDEL were validated by PCR and sequencing in the world-wide strains. These markers were then used to genotype 55 Bathycoccus strains isolated during the winter bloom 2018-2019 in the bay of Banyuls-sur-Mer. With five markers, eight Multi Loci Genotypes (MLG) were determined, two of which represented 53\% and 29\% of the isolates. Physiological studies confirmed that isolates are phenotypically different, cells isolated in February growing better at low temperature than those isolated in December and January. When tested directly on environmental samples, two diversity markers showed a similar allele frequency in sea water as in individual Bathycoccus strains isolated at the same period. We conclude that these markers constitute a resource to identify the most abundant variant alleles in a given bloom. A follow-up on three consecutive blooms revealed differences in allele abundance during the course of a bloom, particularly at initiation and between years. This INDEL-based genotyping constitutes a new methodological approach that may be used to assess the population structure and diversity of other species.},
	keywords = {RCC1613, RCC1615, RCC1868, RCC4222, RCC4752, RCC5417, RCC685},
	doi = {10.1101/2023.02.09.527951},
	url = {http://biorxiv.org/lookup/doi/10.1101/2023.02.09.527951},
	author = {Devic, Martine and Mariac, C{\'e}dric and Verg{\'e}, Val{\'e}rie and Schatt, Philipe and Dennu, Louis and Lozano, Jean-Claude and Bouget, Fran{\c c}ois-Yves and Sabot, Fran{\c c}ois}
}
@booklet {devic_population_2023,
	title = {Population dynamics of the cosmopolitan eukaryotic picophytoplankton Bathycoccus during seasonal blooms in the bay of Banyuls sur Mer (North Western Mediterranean sea)},
	year = {2023},
	publisher = {BioRxiv},
	type = {preprint},
	abstract = {Abstract Although Bathycoccus is one of the most abundant picophytoplankton, little is known about the genetic diversity underlying its adaptation to ecological niches. In this study, the diversity of Bathycoccus populations during their annual bloom in the Mediterranean bay of Banyuls France was assessed by an INDEL based approach. Oxford Nanopore Technology (ONT) was used to characterise structural variants (SV) among the genomes of Bathycoccus sampled from geographically distinct regions in the world ocean. Markers derived from INDEL were validated by PCR and sequencing in the world-wide strains. These markers were then used to genotype 55 Bathycoccus strains isolated during the winter bloom 2018-2019 in Banyuls. With five markers, eight Multi Loci Genotypes (MLG) were determined, two of which represented 53\% and 29\% of the isolates. Physiological studies confirmed that isolates are phenotypically different, cells isolated in February growing better at low temperature than those isolated in December. When tested on environmental samples, two diversity markers showed a similar allele frequency in sea water as in individual Bathycoccus strains isolated at the same period. We conclude that these markers constitute a resource to identify the most abundant variant alleles in a given bloom. A follow-up on three consecutive blooms revealed differences in allele abundance during the course of a bloom, particularly at initiation, and between years. In addition to Bathycoccus prasinos , two other species of Bathycoccus were identified including the recently described species B. calidus and a novel species B. catiminus , suggesting that species diversity of the genus Bathycoccus may be underestimated.},
	keywords = {RCC1613, RCC1615, RCC1868, RCC4222, RCC4752, RCC5417, RCC685},
	doi = {10.1101/2023.02.09.527951},
	url = {http://biorxiv.org/lookup/doi/10.1101/2023.02.09.527951},
	author = {Devic, Martine and Mariac, C{\'e}dric and Verg{\'e}, Val{\'e}rie and Schatt, Philipe and Dennu, Louis and Lozano, Jean-Claude and Bouget, Fran{\c c}ois-Yves and Sabot, Fran{\c c}ois}
}
@article {Paerl2016,
	title = {Use of plankton-derived vitamin B1 precursors, especially thiazole-related precursor, by key marine picoeukaryotic phytoplankton},
	journal = {The ISME Journal},
	volume = {11},
	number = {3},
	year = {2017},
	note = {Publisher: Nature Publishing Group tex.mendeley-tags: rcc3401,rcc745},
	month = {mar},
	pages = {753{\textendash}765},
	keywords = {rcc3401, RCC745},
	issn = {1751-7362},
	doi = {10.1038/ismej.2016.145},
	url = {http://www.nature.com/doifinder/10.1038/ismej.2016.145},
	author = {Paerl, Ryan W and Bouget, Fran{\c c}ois-Yves and Lozano, Jean-Claude and Verg{\'e}, Val{\'e}rie and Schatt, Philippe and Allen, Eric E and Palenik, Brian and Azam, Farooq}
}
