2023-06-29 カリフォルニア大学サンタバーバラ校(UCSB)
◆研究者らは、P. hawaiensisの発生初期の段階で細胞が配置される方法を追跡し、細胞分裂と移動のダイナミックな分析を行った。細胞分裂は乱雑ではなく、細胞は分裂する前に90度回転して配置を維持する。これらの現象は生物学的な信号に関連している可能性があり、成体の構造と機能に依存する組織においては重要である。この研究は、発生生物学の興味深い側面を垣間見るものであり、物理学を生物学の目的に活用する方法を示唆している。
<関連情報>
- https://www.news.ucsb.edu/2023/021108/disorder-lends-robustness-embryonic-development-tiny-shrimp
- https://www.nature.com/articles/s41567-023-02025-3
活発な細胞分裂により、生きた組織で4重の方向秩序相が生成される Active cell divisions generate fourfold orientationally ordered phase in living tissue
Dillon J. Cislo,Fengshuo Yang,Haodong Qin,Anastasios Pavlopoulos,Mark J. Bowick & Sebastian J. Streichan
Nature Physics Published:01 May 2023
DOI:https://doi.org/10.1038/s41567-023-02025-3
Abstract
Morphogenesis, the process through which genes generate form, establishes tissue-scale order as a template for constructing the complex shapes of the body plan. The extensive growth required to build these ordered substrates is fuelled by cell proliferation, which, naively, should destroy order. Understanding how active morphogenetic mechanisms couple cellular and mechanical processes to generate order—rather than annihilate it—remains an outstanding question in animal development. We show that cell divisions are the primary drivers of tissue flow, leading to a fourfold orientationally ordered phase. Waves of anisotropic cell proliferation propagate across the embryo with precise patterning. Defects introduced into the nascent lattice by cell divisions are moved out of the tissue bulk towards the boundary by subsequent divisions. Specific cell proliferation rates and orientations enable cell divisions to organize rather than fluidize the tissue. We observe this using live imaging and tissue cartography to analyse the dynamics of fourfold tissue ordering in the trunk segmental ectoderm of the crustacean Parhyale hawaiensis beginning 72 h after egg lay. The result is a robust, active mechanism for generating global orientational order in a non-equilibrium system that sets the stage for the subsequent development of shape and form.
