Huge congratulations to @mfdspicer.bsky.social, PhD student in our lab, for winning the Best Poster Prize at the 2nd Spatial Genome Organization Conference! 🎉
A proud moment for the lab and well-deserved recognition for his creativity and dedication. 👏
@fusionconf.bsky.social #SGO25

9/ Together these findings reveal a general principle:
Centromere layering emerges from electrostatic polarity — a charge-based asymmetry that repels certain domains outward while the rest integrate inward.

8/ We built a synthetic system: TetR fused to a negatively charged GFP.
When tethered to chromatin, this construct drove loci to the surface — in vitro and in cells.

7/ Adding pure DNA segments to nucleosome arrays was enough to push them outward, in cryoET of chromatin condensates and MD simulations.
👉 Negative charge induces surface targeting.

6/ In vitro chromatin condensates and molecular dynamics simulations showed why.
CENP-B’s acidic domain was sufficient to drive nucleosome arrays to the condensate periphery.

5/ When we depleted kinetochores via CENP-C, centromeres shifted inward.
Knocking out CENP-B further reduced surface localisation.
👉 Kinetochores + CENP-B cooperate to position centromeres at the surface.

4/ Even after condensin depletion and spindle depolymerisation, CENP-A centromere cores still localised at the chromosome periphery.
👉 Surface localisation is independent of loops & spindles.

2/ Why does this matter?
Centromeres must locate at the chromosome surface to allow kinetochores to attach spindle microtubules. If buried inside, microtubules can’t reach kinetochores to segregate chromosomes faithfully.