PT  - JOURNAL ARTICLE
AU  - Jarrett Smith
AU  - Geraldine Seydoux
TI  - Examination of P granule dynamics <em>in vivo</em> and <em>ex vivo</em>
AID  - 10.1101/245878
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 245878
4099  - http://biorxiv.org/content/early/2018/03/05/245878.short
4100  - http://biorxiv.org/content/early/2018/03/05/245878.full
AB  - RNA granules are RNA/protein condensates proposed to form in cells by liquid-liquid phase separation, a thermodynamic process that partitions molecules between two liquid phases without energy input. The C. elegans P granules are RNA granules that exhibit liquid-like behaviors. Using ex vivo methods, we find that P granules are not simple liquids. P granules solidify outside of cells, becoming resistant to dilution and high salt. P granules also solidify in cells upon shift to high temperature or inactivation of the DDX6 RNA helicase. Solidification of RNA granules has been linked to neurodegeneration. Our findings suggest that active processes are needed continuously to counteract the intrinsic propensity of RNA granules to solidify.