TY - JOUR TI - Co-movement of astral microtubules, organelles and F-actin by dynein and actomyosin forces in frog egg cytoplasm AU - Pelletier, James F AU - Field, Christine M AU - Fürthauer, Sebastian AU - Sonnett, Matthew AU - Mitchison, Timothy J A2 - Surrey, Thomas A2 - Malhotra, Vivek A2 - Di Talia, Stefano VL - 9 PY - 2020 DA - 2020/12/07 SP - e60047 C1 - eLife 2020;9:e60047 DO - 10.7554/eLife.60047 UR - https://doi.org/10.7554/eLife.60047 AB - How bulk cytoplasm generates forces to separate post-anaphase microtubule (MT) asters in Xenopus laevis and other large eggs remains unclear. Previous models proposed that dynein-based, inward organelle transport generates length-dependent pulling forces that move centrosomes and MTs outwards, while other components of cytoplasm are static. We imaged aster movement by dynein and actomyosin forces in Xenopus egg extracts and observed outward co-movement of MTs, endoplasmic reticulum (ER), mitochondria, acidic organelles, F-actin, keratin, and soluble fluorescein. Organelles exhibited a burst of dynein-dependent inward movement at the growing aster periphery, then mostly halted inside the aster, while dynein-coated beads moved to the aster center at a constant rate, suggesting organelle movement is limited by brake proteins or other sources of drag. These observations call for new models in which all components of the cytoplasm comprise a mechanically integrated aster gel that moves collectively in response to dynein and actomyosin forces. KW - microtubule KW - dynein KW - ER KW - actin KW - cytoplasm KW - mechanics JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -