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.

动物胞质分裂以形成连接两个新形成的同胞细胞的薄细胞间膜桥结束，最终通过脱落解决。虽然有丝分裂在 15 分钟内完成，但细胞间桥可以持续数小时，维持同胞细胞之间的物理连接并允许交换细胞质成分。尽管细胞间通讯是发育的基础，但细胞间桥梁在胚胎发生过程中的作用尚未完全阐明。在这项工作中，我们表征了早期斑马鱼发育过程中细胞间桥的时空特征。我们发现，在早期胚胎中发生的快速分裂周期中，脱落被延迟，导致相互连接的细胞簇的形成。当胚胎进入中胚层转变 (MBT) 阶段时，脱落加速。驱动脱落的 ESCRT 机器的组成部分在 MBT 后的细胞间桥上富集，并且干扰了 ESCRT 功能，将脱落扩展到 MBT 之外。与其他相邻细胞相比，MBT 的标志性特征，包括转录起始和细胞形状调制，在相互连接的同胞细胞中更为相似。总的来说，我们的研究结果表明，早期胚胎的延迟脱落允许细胞簇在胚胎发育过程中协调它们的行为。与其他相邻细胞相比，相互连接的同胞细胞中的转录起始和细胞形状调制更相似。总的来说，我们的研究结果表明，早期胚胎的延迟脱落允许细胞簇在胚胎发育过程中协调它们的行为。与其他相邻细胞相比，相互连接的同胞细胞中的转录起始和细胞形状调制更相似。总的来说，我们的研究结果表明，早期胚胎的延迟脱落允许细胞簇在胚胎发育过程中协调它们的行为。