Cytokinetic abscission is part of the midblastula transition in early zebrafish embryogenesis

Abstract

Animal cytokinesis ends with the formation of a thin intercellular membrane bridge that connects the two newly formed sibling cells, which is ultimately resolved by abscission. While mitosis is completed within 15 min, the intercellular bridge can persist for hours, maintaining a physical connection between sibling cells and allowing exchange of cytosolic components. Although cell–cell communication is fundamental for development, the role of intercellular bridges during embryogenesis has not been fully elucidated. In this work, we characterized the spatiotemporal characteristics of the intercellular bridge during early zebrafish development. We found that abscission is delayed during the rapid division cycles that occur in the early embryo, giving rise to the formation of interconnected cell clusters. Abscission was accelerated when the embryo entered the midblastula transition (MBT) phase. Components of the ESCRT machinery, which drives abscission, were enriched at intercellular bridges post-MBT and, interfering with ESCRT function, extended abscission beyond MBT. Hallmark features of MBT, including transcription onset and cell shape modulations, were more similar in interconnected sibling cells compared to other neighboring cells. Collectively, our findings suggest that delayed abscission in the early embryo allows clusters of cells to coordinate their behavior during embryonic development.

Control of meiotic chromosomal bouquet and germ cell morphogenesis by the zygotene cilium

“…The Tg(m−act: mCherry-Cep55l) line was generated using the tol2 system. mCherry-cep55l was polymerase chain reaction amplified from a mCherry-cep55l C1 vector (95) and cloned into pDest-Tol2 plasmid under the b-actin promoter using Gibson assembly (E5510S; New England Biolabs).…”

Tunneling nanotubes enable intercellular transfer in zebrafish embryos

“…1G). CEP55 was previously shown to label cytokinetic bridges in the zebrafish embryo throughout their lifespan, from the beginning of bridge formation until the midbody remnant release 20 . In our timelapse recordings CEP55 was present from cytokinetic bridge formation until abscission, while CEP55-positive midbody remnants could also be observed (data not shown).…”

Mechanics and regulation of cytokinetic abscission

“…To our knowledge, there is no study that has measured tension in the ICB in the context of a tissue, in situ . The influence of neighboring cells on furrow ingression and midbody positioning in vivo or in vitro tissues has started to be investigated (e.g., ( Campinho et al, 2013 ; Founounou et al, 2013 ; Guillot and Lecuit, 2013 ; Herszterg et al, 2013 ; Mathieu et al, 2013 ; Morais-de-Sá and Sunkel, 2013 ; Wyatt et al, 2015 ; Cao et al, 2017 ; Pinheiro et al, 2017 ; Daniel et al, 2018 ; Uroz et al, 2019 ; Adar-Levor et al, 2021 ; Little et al, 2021 ; Mathieu et al, 2022 )). However, measuring mechanical parameters in vivo is technically challenging.…”