Li Yuwei, Trivedi Vikas, Truong Thai V, Koos David S, Lansford Rusty, Chuong Cheng-Ming, Warburton David, Moats Rex A, Fraser Scott E
Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125, USA.
Department of Molecular and Computational Biology, University of Southern California, Los Angeles, California, USA.
Nat Commun. 2015 Apr 13;6:6798. doi: 10.1038/ncomms7798.
The diverse morphology of vertebrate skeletal system is genetically controlled, yet the means by which cells shape the skeleton remains to be fully illuminated. Here we perform quantitative analyses of cell behaviours in the growth plate cartilage, the template for long bone formation, to gain insights into this process. Using a robust avian embryonic organ culture, we employ time-lapse two-photon laser scanning microscopy to observe proliferative cells' behaviours during cartilage growth, resulting in cellular trajectories with a spreading displacement mainly along the tissue elongation axis. We build a novel software toolkit of quantitative methods to segregate the contributions of various cellular processes to the cellular trajectories. We find that convergent-extension, mitotic cell division, and daughter cell rearrangement do not contribute significantly to the observed growth process; instead, extracellular matrix deposition and cell volume enlargement are the key contributors to embryonic cartilage elongation.
脊椎动物骨骼系统的多样形态受基因控制，然而细胞塑造骨骼的方式仍有待充分阐明。在此，我们对生长板软骨（长骨形成的模板）中的细胞行为进行定量分析，以深入了解这一过程。利用强大的禽类胚胎器官培养体系，我们采用延时双光子激光扫描显微镜观察软骨生长过程中增殖细胞的行为，得到主要沿组织伸长轴具有扩散位移的细胞轨迹。我们构建了一个新的定量方法软件工具包，以区分各种细胞过程对细胞轨迹的贡献。我们发现，趋同延伸、有丝分裂细胞分裂和子细胞重排对观察到的生长过程贡献不大；相反，细胞外基质沉积和细胞体积增大是胚胎软骨伸长的关键因素。
