Actin organizes chromosomes and microtubules to ensure mitotic fidelity in the preimplantation embryo

• 成果类型: Article
• 署名作者: Hernandez, Blake; Tetlak, Piotr; Domingo-Muelas, Ana; Akizawa, Hiroki; Skory, Robin M.; Ardestani, Goli; Biro, Mate; Liu, Xiaolei; Bissiere, Stephanie; Sakkas, Denny; Plachta, Nicolas
• 署名单位: University of Pennsylvania; University of Pennsylvania; University of Pennsylvania; Garvan Institute of Medical Research; European Molecular Biology Laboratory (EMBL); EMBL Australia; University of New South Wales Sydney; University of Pennsylvania
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-13569
• DOI: 10.1126/science.ads1234
• 发表日期: 2025-05-22
• 关键词: spindle; centrosome; DYNAMICS; complex

摘要

Following fertilization, the preimplantation embryo undergoes successive rounds of cell division and must accurately propagate the genetic material to ensure successful development. However, early mammalian embryos lack efficient spindle assembly mechanisms, and it remains unclear how error-free chromosome segregation is achieved. In this work, we imaged early mouse embryos and identified a network of nuclear actin cables that organize prophase chromosomes at the nuclear periphery. Following nuclear envelope breakdown, the network contracts and gathers chromosomes toward the cell center. Network contraction was driven by filament disassembly in a myosin II-independent manner. Additionally, we identified a network of branched actin filaments that attenuates metaphase spindle elongation. We also visualized nuclear actin in human embryos, suggesting a conserved role for actin in ensuring mitotic fidelity during early mammalian development.