PT - JOURNAL ARTICLE AU - Bertrand Bénazéraf AU - Mathias Beaupeux AU - Martin Tchernookov AU - Allison Wallingford AU - Tasha Salisbury AU - Amelia Shirtz AU - Andrew Shirtz AU - Dave Huss AU - Olivier Pourquié AU - Paul François AU - Rusty Lansford TI - Multiscale quantification of tissue behavior during amniote embryo axis elongation AID - 10.1101/053124 DP - 2017 Jan 01 TA - bioRxiv PG - 053124 4099 - http://biorxiv.org/content/early/2017/02/10/053124.short 4100 - http://biorxiv.org/content/early/2017/02/10/053124.full AB - Embryonic axis extension is a complex multi-tissue morphogenetic process responsible for the formation of the posterior part of the amniote body. Cells located in the caudal part of the embryo divide and rearrange to participate in the elongation of the different embryonic tissues (e.g. neural tube, axial and paraxial mesoderm, lateral plate, ectoderm, endoderm). We previously identified the paraxial mesoderm as a crucial player of axis elongation, but how movements and growth are coordinated between the different posterior tissues to drive morphogenesis remain largely unknown. Here we use the quail embryo as a model system to quantify cell behavior and movements in the various tissues of the elongating embryo. We first quantify the tissue-specific contribution to axis elongation by using 3D volumetric techniques, then quantify tissue-specific parameters such as cell density and proliferation at different embryonic stages. To be able to study cell behavior at a multi-tissue scale we used high-resolution 4D imaging of transgenic quail embryos expressing constitutively expressed fluorescent proteins. We developed specific tracking and image analysis techniques to analyze cell motion and compute tissue deformations in 4D. This analysis reveals extensive sliding between tissues during axis extension. Further quantification of “tissue tectonics” showed patterns of rotations, contractions and expansions, which are coherent with the multi-tissue behavior observed previously. Our results confirm the central role of the PSM in axis extension; we propose that the PSM specific cell proliferation and migration programs control the coordination of elongation between tissues during axis extension.