Annuaire
Jose Maria MARTIN-DURAN, Queen Mary University of London
| Quand ? |
Le 13/03/2026, de 11:00 à 12:00 |
|---|---|
| S'adresser à | Equipe Loppin, Salle des thèses |
| Ajouter un événement au calendrier |
vCal
iCal
|
The temporally and spatially collinear expression of Hox genes along the anteroposterior axis is a hallmark of animal development and a crucial evolutionary milestone linked to the diversification of animal body plans and life cycles. However, how their exquisite, coordinated expression originated remains unknown because we lack an understanding of the molecular mechanisms and genomic regulatory principles controlling gene expression in most animals. Here, we use high-resolution Micro-C datasets spanning the life cycle of two segmented worms (Annelida) to demonstrate that the formation of a Topologically Associating Domain (TAD) correlates with distinct timings of Hox gene activation. In both species, an architectural stripe along the posterior TAD border marks the presence of a ‘global control region’ that interacts with all Hox genes. Moreover, the formation of nested sub-TADs correlates with the temporal collinearity of Hox genes in one species. Histone post-translational modification profiling reveals opposing dynamics of polycomb-mediated repressive (H3K27me3) and permissive (H3K4me3; H3K4me1) marks, linked to activation of the ‘global control region’. Together, our findings shift current thinking about the evolution of genome regulation and Hox gene expression in animals, proposing a new model that mechanistically links chromatin conformation dynamics to the unfolding of Hox collinearity in a non-vertebrate animal.
Contact : Emmanuel Gonzalez