Dynamic imaging of the growth plate cartilage reveals multiple contributors to skeletal morphogenesis

• Published in: Nature communications Vol. 6; no. 1; p. 6798
• Main Authors: Li, Yuwei, Trivedi, Vikas, Truong, Thai V, Koos, David S, Lansford, Rusty, Chuong, Cheng-Ming, Warburton, David, Moats, Rex A, Fraser, Scott E
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 13.04.2015; Nature Pub. Group
• Subjects: Animals; Bone growth; Cartilage; Cartilage - embryology; Cartilage - metabolism; Cartilage - ultrastructure; Cell culture; Cell Division; Cell Movement; Cell Size; Chick Embryo; Chondrocytes - metabolism; Chondrocytes - ultrastructure; Confocal microscopy; Elongation; Embryos; Enlargement; Extracellular matrix; Extracellular Matrix - chemistry; Extracellular Matrix - metabolism; Fibroblasts - metabolism; Fibroblasts - ultrastructure; Gene Expression; Genes, Reporter; Genetic Vectors; Green Fluorescent Proteins - genetics; Green Fluorescent Proteins - metabolism; Growth plate; Growth Plate - embryology; Growth Plate - metabolism; Growth Plate - ultrastructure; Long bone; Metacarpal Bones - embryology; Metacarpal Bones - metabolism; Metacarpal Bones - ultrastructure; Microscopy; Microscopy, Confocal; Morphogenesis; Morphology; Organ culture; Organ Culture Techniques; Osteogenesis; Osteogenesis - physiology; Photons; Retroviridae - genetics; Scanning microscopy; Skeletal system; Skeleton; Time-Lapse Imaging; Trajectories; Vertebrates
• ISSN: 2041-1723; 2041-1723
• 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.