@article {69904,
	title = {Quantitative spatial analysis of chromatin biomolecular condensates using cryoelectron tomography.},
	journal = {Proc Natl Acad Sci U S A},
	volume = {122},
	year = {2025},
	month = {2025 May 13},
	pages = {e2426449122},
	abstract = {<p>Phase separation is an important mechanism to generate certain biomolecular condensates and organize the cell interior. Condensate formation and function remain incompletely understood due to difficulties in visualizing the condensate interior at high resolution. Here, we analyzed the structure of biochemically reconstituted chromatin condensates through cryoelectron tomography. We found that traditional blotting methods of sample preparation were inadequate, and high-pressure freezing plus focused ion beam milling was essential to maintain condensate integrity. To identify densely packed molecules within the condensate, we integrated deep learning-based segmentation with context-aware template matching. Our approaches were developed on chromatin condensates and were also effective on condensed regions of in situ native chromatin. Using these methods, we determined the average structure of nucleosomes to 6.1 and 12 {\r A} resolution in reconstituted and native systems, respectively, found that nucleosomes form heterogeneous interaction networks in both cases, and gained insight into the molecular origins of surface tension in chromatin condensates. Our methods should be applicable to biomolecular condensates containing large and distinctive components in both biochemical reconstitutions and certain cellular systems.</p>

<p>Preprint:\&nbsp;https://www.biorxiv.org/content/10.1101/2024.12.01.626131v2</p>
},
	keywords = {Animals, Biomolecular Condensates, Chromatin, Cryoelectron Microscopy, Electron Microscope Tomography, Nucleosomes},
	issn = {1091-6490},
	doi = {10.1073/pnas.2426449122},
	url = {https://doi.org/10.1073/pnas.2426449122},
	author = {Zhou, Huabin and Hutchings, Joshua and Shiozaki, Momoko and Zhao, Xiaowei and Doolittle, Lynda K and Yang, Shixin and Yan, Rui and Jean, Nikki and Riggi, Margot and Yu, Zhiheng and Villa, Elizabeth and Rosen, Michael K}
}
