@flatironinstitute.org scientists tested a theory that treated chromosome-separating cellular structures (spindles) as active liquid crystals: www.simonsfoundation.org/2026/02/12/the-machinery... #science #biology
New research from @flatironinstitute.org scientists found that spindles self-organize like active liquid crystals: www.simonsfoundation.org/2026/02/12/t... #science #biology
These results indicate that human metaphase spindle organization emerges from local microtubule–microtubule interactions alongside chromosome-specific interactions, with well-defined limits to continuum descriptions.
🧵6/6
Furthermore, we demonstrate that there are fundamental limits to testing the theory below ~300 nm, set by the discrete nature of the microtubule network.
🧵5/6
However, leveraging ET data, we were able to subset microtubules that are directly connected to chromosomes. For this chromosome-associated subpopulation, we find that their organization is shaped by additional mechanisms not captured by the simple liquid crystal theory.
🧵4/6
An active liquid crystal theory based primarily on local microtubule–microtubule interactions captures key features of microtubule organization observed experimentally.
🧵3/6
To our knowledge, this work provides the first rigorous test of the active liquid crystal framework at spatial resolutions approaching the mean microtubule spacing, using data from both live-cell microscopy and electron tomography (ET).
🧵2/6
Our work on studying the organization of the human metaphase spindle is now published in PNAS 🎉🎉 pnas.org/doi/10.1073/...
Joint work with Colm Kelleher under the #CCBx initiative
@flatironinstitute.org
🧵1/6
Accepted to #NeurIPS25! 🥳 Big congrats to Stephen !! glad to be part of it @flatironinstitute.org
Excited to share our paper on learning stochastic processes from cross-sectional biological data, now out in @pnas.org
🎉
www.pnas.org/doi/10.1073/...
5/5 In summary, even in complex cellular organelles like the spindle, active-matter physics combined with carefully measured data yields predictive theories.
4/5 Our model reveals that spindle organization is governed by: local MT alignment interaction, diffusive-like motion, directed transport & MT turnover dynamics, all encoded in our continuum theory with interpretable and measurable parameters.
3/5 We demonstrate that a simple coarse-grained active liquid crystal model can quantitatively explain both the mean structure and fluctuation spectra of the spindle microtubule network.
2/5 How do thousands of microtubules and associated proteins self-organize into the mitotic mammalian spindle ?
We combine detailed static ultrastructural data from electron tomography with dynamic polarization microscopy 🔬 measurements to find out.
🧵1/5 Excited to share our new paper:
"Active Liquid Crystal Theory Explains the Collective Organization of Microtubules in Human Mitotic Spindles". Joint work with Colm Kelleher (now at Syracuse, previously Harvard) @flatironinstitute.org
arxiv.org/abs/2507.22273
🚀Excellent follow-up by Stephen extending Probability Flow Inference to account for cell proliferation. SOTA performance on time-resolved scRNA-seq to infer transcriptional flow dynamics.
In short: inverting the Fokker-Planck in 10–20D with cell growth @ arxiv.org/pdf/2505.13197
Mark your calendars!! 🗓️ The third Young Biophysicists Meeting will be held on the coming Monday (May 5th) from 11am - 12pm EST. We have four exciting talks lined up for you, see you all soon! Find out more : shorturl.at/4oKNe
Three small video stills that show the path a simulated bacteria takes through an obstacle-filled liquid.
A new theoretical model developed by #FlatironCCB scientist @henryhmattingly.bsky.social predicts how bacteria disperse in crowded spaces, opening the door for strategies to control their spread. Read more: www.simonsfoundation.org/2025/03/21/n... #science #biology
Existing biophysics summer school in Greece !! please forward this to anyone interested..
