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Cécile COURRET, Paris Saclay
| When |
Jun 26, 2025
from 11:00 to 12:00 |
|---|---|
| Contact Name | Equipe Loppin, Salle des Thèses |
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Selfish genetic elements are a major source of genomic conflict, promoting their own transmission even at the expense of organismal fitness. My research focuses on the molecular mechanisms underlying these conflicts and their evolutionary consequences. By investigating how selfish elements interfere with essential processes—such as meiosis and heterochromatin regulation—and how organisms respond to such disruptions, we can gain deeper insights into genome function and evolution.
One powerful model we study is an X-linked meiotic drive system in Drosophila simulans that disrupts Y chromosome segregation during meiosis II, leading to a highly female-biased sex ratio. This drive is mediated by two cooperating X-linked loci: one within a segmental duplication and the other identified as HP1D2, a young, rapidly evolving member of the Heterochromatin Protein 1 family. HP1D2 localizes to the heterochromatic Y chromosome in spermatogonia, suggesting a role in modifying heterochromatin to control sister chromatid segregation.
In natural populations, the spread of this drive is counteracted by autosomal suppressors and resistant Y chromosomes. Because this conflict system remains active and evolving in nature, it offers a rare opportunity to study intragenomic conflict in real-time. Our work sheds light on the genetic architecture and evolutionary dynamics of this system, enhancing our understanding of how meiotic drivers shape genome evolution and regulation.
Contact : B. Loppin