RT Journal Article SR Electronic T1 Multiscale quantification of tissue behavior during amniote embryo axis elongation JF bioRxiv FD Cold Spring Harbor Laboratory SP 053124 DO 10.1101/053124 A1 Bertrand Bénazéraf A1 Mathias Beaupeux A1 Martin Tchernookov A1 Allison Wallingford A1 Tasha Salisbury A1 Amelia Shirtz A1 Andrew Shirtz A1 Dave Huss A1 Olivier Pourquié A1 Paul François A1 Rusty Lansford YR 2016 UL http://biorxiv.org/content/early/2016/05/13/053124.abstract 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 different tissues of the elongating embryo. We first quantify 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” revealed 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.