Dr. Eugene Gladyshev

Molecular Genetics and Epigenetics Unit, Department of Mycology, Institut Pasteur

“Homology-dependent initiation of gene silencing in N.crassa is mediated by ATRX/SAD-6.” 

Abstract: Our group studies several genome-defense processes in the fungus Neurospora crassa, with the goal of identifying the mechanisms that initiate gene silencing, either transcriptional or post-transcriptional, in response to DNA homology. These processes include meiotic silencing by unpaired DNA (MSUD), repeat-induced point mutation (RIP, with a focus on the pathway mediated by the SUV39-family methyltransferase DIM-5), and, more recently, repeat-induced gene silencing (RIGS). We found that all three processes absolutely require SAD-6, the N. crassa ortholog of the chromatin remodeler ATRX. We further found that SAD-6 mediates a broader range of silencing phenomena that appear to target perturbed chromatin. Together, these results identify ATRX/SAD-6 as a functional link between recombination-independent DNA pairing and the initiation of gene silencing, and further suggest that such pairing may be recognized as a particular instance of perturbed chromatin.

The seminar will take place in the Institut Jacques Monod seminar room (RB-18B).
Bâtiment Buffon, 15 rue Hélène Brion, Paris 13^th.

On Wednesday, November 18^th at 11:00 am.

Zoom link for remote attendees:
https://u-paris.zoom.us/j/86114422072?pwd=VzJ0c2pxcHl4OWppekx3MldlM2Y4QT09
Meeting ID: 861 1442 2072
Secret code:  492809

Relevant publications from the speaker

1. Aguilera, P. & López-Contreras, A. J. ATRX, a guardian of chromatin.Trends Genet.39, 505–519 (2023).
2. Gladyshev, E. & Kleckner, N. DNA sequence homology induces cytosine-to-thymine mutation by a heterochromatin-related pathway in Neurospora. Nat. Genet.49, 887–894 (2017).
3. Carlier, F.et al.Remodeling of perturbed chromatin can initiate de novo transcriptional and post-transcriptional silencing. Proc. Natl. Acad. Sci. U. S. A. 121, e2402944121 (2024).
4. Carlier, F. et al. SAD-6/ATRX enables broad genome surveillance and defense in fungi. Preprint (2026).