TY - JOUR TI - Distinct mesoderm migration phenotypes in extra-embryonic and embryonic regions of the early mouse embryo AU - Saykali, Bechara AU - Mathiah, Navrita AU - Nahaboo, Wallis AU - Racu, Marie-Lucie AU - Hammou, Latifa AU - Defrance, Matthieu AU - Migeotte, Isabelle A2 - Solnica-Krezel, Lilianna A2 - Cooper, Jonathan A A2 - Solnica-Krezel, Lilianna A2 - Williams, Margot VL - 8 PY - 2019 DA - 2019/04/05 SP - e42434 C1 - eLife 2019;8:e42434 DO - 10.7554/eLife.42434 UR - https://doi.org/10.7554/eLife.42434 AB - In mouse embryo gastrulation, epiblast cells delaminate at the primitive streak to form mesoderm and definitive endoderm, through an epithelial-mesenchymal transition. Mosaic expression of a membrane reporter in nascent mesoderm enabled recording cell shape and trajectory through live imaging. Upon leaving the streak, cells changed shape and extended protrusions of distinct size and abundance depending on the neighboring germ layer, as well as the region of the embryo. Embryonic trajectories were meandrous but directional, while extra-embryonic mesoderm cells showed little net displacement. Embryonic and extra-embryonic mesoderm transcriptomes highlighted distinct guidance, cytoskeleton, adhesion, and extracellular matrix signatures. Specifically, intermediate filaments were highly expressed in extra-embryonic mesoderm, while live imaging for F-actin showed abundance of actin filaments in embryonic mesoderm only. Accordingly, Rhoa or Rac1 conditional deletion in mesoderm inhibited embryonic, but not extra-embryonic mesoderm migration. Overall, this indicates separate cytoskeleton regulation coordinating the morphology and migration of mesoderm subpopulations. KW - gastrulation KW - cell migration KW - cytoskeleton KW - extra-embryonic KW - live Imaging KW - RhoGTPases JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -