Frédéric Verret

@article{grypioti_dicerdependent_2023,
title = {Dicer‐dependent heterochromatic small textlessspan style=},
author = {Emilia Grypioti and Hugues Richard and Nikoleta Kryovrysanaki and Marianne Jaubert and Angela Falciatore and Frédéric Verret and Kriton Kalantidis},
url = {https://imbbc.hcmr.gr/wp-content/uploads/2023/12/2023-Grypioti-E-New-Phytol-63.pdf
https://nph.onlinelibrary.wiley.com/doi/10.1111/nph.19429},
doi = {10.1111/nph.19429},
issn = {0028-646X, 1469-8137},
year = {2023},
date = {2023-12-11},
urldate = {2023-12-11},
journal = {New Phytologist},
pages = {nph.19429},
abstract = {Summary



Diatoms are eukaryotic microalgae responsible for nearly half of the marine productivity. RNA interference (RNAi) is a mechanism of regulation of gene expression mediated by small RNAs (sRNAs) processed by the endoribonuclease Dicer (DCR). To date, the mechanism and physiological role of RNAi in diatoms are unknown.



We mined diatom genomes and transcriptomes for key RNAi effectors and retraced their phylogenetic history. We generated DCR knockout lines in the model diatom species
Phaeodactylum tricornutum
and analyzed their mRNA and sRNA populations, repression‐associated histone marks, and acclimatory response to nitrogen starvation.




Diatoms presented a diversification of key RNAi effectors whose distribution across species suggests the presence of distinct RNAi pathways.
P. tricornutum
DCR was found to process 26–31‐nt‐long double‐stranded sRNAs originating mostly from transposons covered by repression‐associated epigenetic marks. In parallel,
P. tricornutum
DCR was necessary for the maintenance of the repression‐associated histone marks H3K9me2/3 and H3K27me3. Finally, PtDCR‐KO lines presented a compromised recovery post nitrogen starvation suggesting a role for
P. tricornutum
DCR in the acclimation to nutrient stress.




Our study characterized the molecular function of the single DCR homolog of
P. tricornutum
suggesting an association between RNAi and heterochromatin maintenance in this model diatom species.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{amaral_ion-driven_2023,
title = {Ion-driven communication and acclimation strategies in microalgae},
author = {Raquel Amaral and Damiano Duci and Francisco C Cotta and Felipe L Bacellar and Soraia Oliveira and Frédéric Verret and Kamal Asadi and Lode K J Vandamme and Nuno M Reis and Lee D Bryant and David Tosh and Jean-Luc Mouget and Rupert Perkins and Paulo R F Rocha},
url = {https://imbbc.hcmr.gr/wp-content/uploads/2023/09/2023-Amaral-R-Chem-Engineer-47.pdf
https://linkinghub.elsevier.com/retrieve/pii/S1385894723037166},
doi = {10.1016/j.cej.2023.144985},
issn = {13858947},
year = {2023},
date = {2023-09-11},
urldate = {2023-09-14},
journal = {Chemical Engineering Journal},
volume = {473},
pages = {144985},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{gabed_what_2022,
title = {What Was Old Is New Again: The Pennate Diatom Haslea ostrearia (Gaillon) Simonsen in the Multi-Omic Age},
author = {Noujoud Gabed and Frédéric Verret and Aurélie Peticca and Igor Kryvoruchko and Romain Gastineau and Orlane Bosson and Julie Séveno and Olga Davidovich and Nikolai Davidovich and Andrzej Witkowski and Jon Bent Kristoffersen and Amel Benali and Efstathia Ioannou and Aikaterini Koutsaviti and Vassilios Roussis and Hélène Gâteau and Suliya Phimmaha and Vincent Leignel and Myriam Badawi and Feriel Khiar and Nellie Francezon and Mostefa Fodil and Pamela Pasetto and Jean-Luc Mouget},
url = {https://imbbc.hcmr.gr/wp-content/uploads/2022/05/2022-Gabed-N-Mar-Drugs-33.pdf
https://www.mdpi.com/1660-3397/20/4/234},
doi = {10.3390/md20040234},
issn = {1660-3397},
year = {2022},
date = {2022-01-01},
urldate = {2022-05-09},
journal = {Marine Drugs},
volume = {20},
number = {4},
pages = {234},
abstract = {The marine pennate diatom Haslea ostrearia has long been known for its characteristic blue pigment marennine, which is responsible for the greening of invertebrate gills, a natural phenomenon of great importance for the oyster industry. For two centuries, this taxon was considered unique; however, the recent description of a new blue Haslea species revealed unsuspected biodiversity. Marennine-like pigments are natural blue dyes that display various biological activities—e.g., antibacterial, antioxidant and antiproliferative—with a great potential for applications in the food, feed, cosmetic and health industries. Regarding fundamental prospects, researchers use model organisms as standards to study cellular and physiological processes in other organisms, and there is a growing and crucial need for more, new and unconventional model organisms to better correspond to the diversity of the tree of life. The present work, thus, advocates for establishing H. ostrearia as a new model organism by presenting its pros and cons—i.e., the interesting aspects of this peculiar diatom (representative of benthic-epiphytic phytoplankton, with original behavior and chemodiversity, controlled sexual reproduction, fundamental and applied-oriented importance, reference genome, and transcriptome will soon be available); it will also present the difficulties encountered before this becomes a reality as it is for other diatom models (the genetics of the species in its infancy, the transformation feasibility to be explored, the routine methods needed to cryopreserve strains of interest).},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{gastineau_two_2020,
title = {Two new bacilladnaviruses associated with the diatom Haslea ostrearia},
author = {Romain Gastineau and Claude Lemieux and Monique Turmel and Emilia Grypioti and Frédéric Verret and Antonios Makris and Anagnostis Argiriou and Dimitris Kafetzopoulos and Irina Stratidaki and Gregory Carrier and Boris Jacquette and Jean-Luc Mouget},
url = {https://www.tandfonline.com/doi/full/10.1080/09670262.2020.1748723},
doi = {10.1080/09670262.2020.1748723},
issn = {0967-0262, 1469-4433},
year = {2020},
date = {2020-06-01},
urldate = {2020-08-18},
journal = {European Journal of Phycology},
pages = {1--10},
abstract = {Haslea ostrearia (Gaillon) Simonsen is famous among diatoms for producing a blue pigment. Genome sequencing of different strains of H. ostrearia led to the discovery of the complete genomes of two new bacilladnaviruses, HOV-148 and HOV-235. The DNA sequences of these viruses were identified in H. ostrearia strains that had been maintained for several years in a culture collection. Some of these strains are the products of in vitro episodes of auxosporulation and thus have never been in contact with their natural biotope. At 4567 and 4538 bp, the HOV-148 and HOV-235 genomes are shorter than those of most diatom-infecting viruses known to date. They each contain four open reading frames and display highest similarities with sequences from viruses found in a gastropod from New Zealand, a proximity confirmed by phylogenetic analysis. HOV-148 and HOV-235 were identified in three clones of H. ostrearia that were collected in oyster ponds from distinct locations in the Bay of Bourgneuf (France). Given that our search for similar viral sequences in genomic data derived from other sub-populations or species of the genus Haslea throughout the world was unsuccessful, we hypothesize that these viruses could have a link with the peculiar biotope of the oyster ponds.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}