Title | Soft viscoelastic properties of nuclear actin age oocytes due to gravitational creep. |
Publication Type | Journal Article |
Year of Publication | 2015 |
Authors | Feric, M, Broedersz, CP, Brangwynne, CP |
Journal | Sci Rep |
Volume | 5 |
Pagination | 16607 |
Date Published | 2015 Nov 18 |
ISSN | 2045-2322 |
Keywords | Actins, Animals, Cell Nucleus, Cellular Senescence, Elasticity, Gravitation, Models, Biological, Oocytes, Organelles, Rheology, Viscosity, Xenopus laevis |
Abstract | <p>The actin cytoskeleton helps maintain structural organization within living cells. In large X. laevis oocytes, gravity becomes a dominant force and is countered by a nuclear actin network that prevents liquid-like nuclear bodies from immediate sedimentation and coalescence. However, nuclear actin's mechanical properties, and how they facilitate the stabilization of nuclear bodies, remain unknown. Using active microrheology, we find that nuclear actin forms a weak viscoelastic network, with a modulus of roughly 0.1 Pa. Embedded probe particles subjected to a constant force exhibit continuous displacement, due to viscoelastic creep. Gravitational forces also cause creep displacement of nuclear bodies, resulting in their asymmetric nuclear distribution. Thus, nuclear actin does not indefinitely support the emulsion of nuclear bodies, but only kinetically stabilizes them by slowing down gravitational creep to ~2 months. This is similar to the viability time of large oocytes, suggesting gravitational creep ages oocytes, with fatal consequences on long timescales.</p> |
DOI | 10.1038/srep16607 |
Alternate Journal | Sci Rep |
PubMed ID | 26577186 |
PubMed Central ID | PMC4649616 |
Grant List | DP2 GM105437 / GM / NIGMS NIH HHS / United States 1DP2GM105437-01 / DP / NCCDPHP CDC HHS / United States |