PT  - JOURNAL ARTICLE
AU  - Antoine Hoguin
AU  - Feng Yang
AU  - Agnès Groisillier
AU  - Chris Bowler
AU  - Auguste Genovesio
AU  - Ouardia Ait-Mohamed
AU  - Fabio Rocha Jimenez Vieira
AU  - Leila Tirichine
TI  - Insights into the diversity and function of DNA methyltransferases in microeukaryotes using the model diatom <em>Phaeodactylum tricornutum</em>
AID  - 10.1101/2021.06.11.447926
DP  - 2022 Jan 01
TA  - bioRxiv
PG  - 2021.06.11.447926
4099  - http://biorxiv.org/content/early/2022/08/03/2021.06.11.447926.short
4100  - http://biorxiv.org/content/early/2022/08/03/2021.06.11.447926.full
AB  - Cytosine methylation is an important epigenetic mark involved in the transcriptional control of transposable elements in mammals, plants and fungi. The Stramenopiles-Alveolate-Rhizaria lineages are a major group of ecologically important marine microeukaryotes that include the main phytoplankton groups diatoms and dinoflagellates. However, little is known about their DNA methyltransferase diversity. Here, we performed an in-silico analysis of DNA methyltransferases found in marine microeukaryotes and showed that they encode divergent DNMT3, DNMT4, DNMT5 and DNMT6 enzymes. Furthermore, we revealed three novel classes of enzymes within the DNMT5 family. Using a CRISPR/Cas9 strategy we demonstrated that the loss of the DNMT5a gene correlates with a global depletion of DNA methylation and overexpression of young transposable elements in the model diatom Phaeodactylum tricornutum. The study provides a pioneering view of the structure and function of a DNMT family in the SAR supergroup using an attractive model species.Competing Interest StatementThe authors have declared no competing interest.