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

Abstract

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.

Possible Contribution of Wnt-Responsive Chondroprogenitors to the Postnatal Murine Growth Plate

“…Matrix production and accumulation are also important for interstitial growth. Cell hypertrophy greatly increases the tissue space, which is suggested to be responsible for the longitudinal tissue volume . In addition, recent studies have indicated that growth plate chondrocytes serve as osteoprogenitors and directly contribute to trabecular and cortical bone formation …”

Distribution of neurosensory progenitor pools during inner ear morphogenesis unveiled by cell lineage reconstruction

“…Recent developments in 4D-microscopy imaging and cell tracking tools permit now simultaneous measurements at high spatial-temporal coverage and resolution, and therefore the assessment of cell lineages and cell behaviors including displacements and proliferations (Amat et al, 2014; Blanpain and Simons, 2013; Faure et al, 2016; Keller, 2013; Li et al, 2015; Olivier et al, 2010; Truong et al, 2011). Thus, it is time to progress in filling the void between gene regulatory networks and tissue architecture.…”

Nanoscale bio-platforms for living cell interrogation: current status and future perspectives

“…In addition, Armbruster et al developed designer receptors which could be activated by a designer drug (DREADD) encoded on retroviral vectors pBabepuro, which could be used to probe whole-brain functional networks and behaviors of specific cell types stimulated and inhibited by chemicals 93,94 . This method has demonstrated high-resolution, enabling identification of heterogeneities of basal ganglia pathway, selective functional activation of the extended amygdala circuit and many tasks which could not be easily achieved by PETs 95 [103][104][105] , and plant viruses, such as cowpea chlorotic mottle virus (CCMV) 106 and cowpea mosaic virus (CPMV) [107][108][109] .…”