--- _id: '13229' abstract: - lang: eng text: Dynamic reorganization of the cytoplasm is key to many core cellular processes, such as cell division, cell migration, and cell polarization. Cytoskeletal rearrangements are thought to constitute the main drivers of cytoplasmic flows and reorganization. In contrast, remarkably little is known about how dynamic changes in size and shape of cell organelles affect cytoplasmic organization. Here, we show that within the maturing zebrafish oocyte, the surface localization of exocytosis-competent cortical granules (Cgs) upon germinal vesicle breakdown (GVBD) is achieved by the combined activities of yolk granule (Yg) fusion and microtubule aster formation and translocation. We find that Cgs are moved towards the oocyte surface through radially outward cytoplasmic flows induced by Ygs fusing and compacting towards the oocyte center in response to GVBD. We further show that vesicles decorated with the small Rab GTPase Rab11, a master regulator of vesicular trafficking and exocytosis, accumulate together with Cgs at the oocyte surface. This accumulation is achieved by Rab11-positive vesicles being transported by acentrosomal microtubule asters, the formation of which is induced by the release of CyclinB/Cdk1 upon GVBD, and which display a net movement towards the oocyte surface by preferentially binding to the oocyte actin cortex. We finally demonstrate that the decoration of Cgs by Rab11 at the oocyte surface is needed for Cg exocytosis and subsequent chorion elevation, a process central in egg activation. Collectively, these findings unravel a yet unrecognized role of organelle fusion, functioning together with cytoskeletal rearrangements, in orchestrating cytoplasmic organization during oocyte maturation. acknowledgement: This work was supported by funding from the European Union (European Research Council Advanced grant 742573) to C.-P.H. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. article_processing_charge: No article_type: original author: - first_name: Shayan full_name: Shamipour, Shayan id: 40B34FE2-F248-11E8-B48F-1D18A9856A87 last_name: Shamipour - first_name: Laura full_name: Hofmann, Laura id: b88d43f2-dc74-11ea-a0a7-e41b7912e031 last_name: Hofmann - first_name: Irene full_name: Steccari, Irene id: 2705C766-9FE2-11EA-B224-C6773DDC885E last_name: Steccari - first_name: Roland full_name: Kardos, Roland id: 4039350E-F248-11E8-B48F-1D18A9856A87 last_name: Kardos - first_name: Carl-Philipp J full_name: Heisenberg, Carl-Philipp J id: 39427864-F248-11E8-B48F-1D18A9856A87 last_name: Heisenberg orcid: 0000-0002-0912-4566 citation: ama: Shamipour S, Hofmann L, Steccari I, Kardos R, Heisenberg C-PJ. Yolk granule fusion and microtubule aster formation regulate cortical granule translocation and exocytosis in zebrafish oocytes. PLoS Biology. 2023;21(6):e3002146. doi:10.1371/journal.pbio.3002146 apa: Shamipour, S., Hofmann, L., Steccari, I., Kardos, R., & Heisenberg, C.-P. J. (2023). Yolk granule fusion and microtubule aster formation regulate cortical granule translocation and exocytosis in zebrafish oocytes. PLoS Biology. Public Library of Science. https://doi.org/10.1371/journal.pbio.3002146 chicago: Shamipour, Shayan, Laura Hofmann, Irene Steccari, Roland Kardos, and Carl-Philipp J Heisenberg. “Yolk Granule Fusion and Microtubule Aster Formation Regulate Cortical Granule Translocation and Exocytosis in Zebrafish Oocytes.” PLoS Biology. Public Library of Science, 2023. https://doi.org/10.1371/journal.pbio.3002146. ieee: S. Shamipour, L. Hofmann, I. Steccari, R. Kardos, and C.-P. J. Heisenberg, “Yolk granule fusion and microtubule aster formation regulate cortical granule translocation and exocytosis in zebrafish oocytes,” PLoS Biology, vol. 21, no. 6. Public Library of Science, p. e3002146, 2023. ista: Shamipour S, Hofmann L, Steccari I, Kardos R, Heisenberg C-PJ. 2023. Yolk granule fusion and microtubule aster formation regulate cortical granule translocation and exocytosis in zebrafish oocytes. PLoS Biology. 21(6), e3002146. mla: Shamipour, Shayan, et al. “Yolk Granule Fusion and Microtubule Aster Formation Regulate Cortical Granule Translocation and Exocytosis in Zebrafish Oocytes.” PLoS Biology, vol. 21, no. 6, Public Library of Science, 2023, p. e3002146, doi:10.1371/journal.pbio.3002146. short: S. Shamipour, L. Hofmann, I. Steccari, R. Kardos, C.-P.J. Heisenberg, PLoS Biology 21 (2023) e3002146. date_created: 2023-07-16T22:01:09Z date_published: 2023-06-08T00:00:00Z date_updated: 2023-08-02T06:33:14Z day: '08' ddc: - '570' department: - _id: CaHe doi: 10.1371/journal.pbio.3002146 ec_funded: 1 external_id: isi: - '001003199100005' pmid: - '37289834' file: - access_level: open_access checksum: 8e88cb0e5a6433a2f1939a9030bed384 content_type: application/pdf creator: dernst date_created: 2023-07-18T07:59:58Z date_updated: 2023-07-18T07:59:58Z file_id: '13246' file_name: 2023_PloSBiology_Shamipour.pdf file_size: 4431723 relation: main_file success: 1 file_date_updated: 2023-07-18T07:59:58Z has_accepted_license: '1' intvolume: ' 21' isi: 1 issue: '6' language: - iso: eng month: '06' oa: 1 oa_version: Published Version page: e3002146 pmid: 1 project: - _id: 260F1432-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '742573' name: Interaction and feedback between cell mechanics and fate specification in vertebrate gastrulation publication: PLoS Biology publication_identifier: eissn: - 1545-7885 publication_status: published publisher: Public Library of Science quality_controlled: '1' scopus_import: '1' status: public title: Yolk granule fusion and microtubule aster formation regulate cortical granule translocation and exocytosis in zebrafish oocytes tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: journal_article user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8 volume: 21 year: '2023' ...