Fig 10. Live imaging of the mesodermal cells reveal their trajectories during gastrulation.

(A) Image sequence from time-lapse video (S1 Movie) of an T^{nGPF-CreERT2/+}; R26^mgpf/+ embryo resulting from the administration of tamoxifen at around E6.5 (overnight timed matings). Yellow arrows point to progenitor initially located in proximity to the node/distal regions and migrating along the midline in medial regions of the prospective cardiac crescent. Red arrows point to progenitors initially located proximally and migrated towards posterior regions of the prospective cardiac crescent and posterior second heart field. Blue arrow points to a progenitor located at the embryonic-extraembryonic border. Images are z-maximum projection of 37 sections acquired every 5 μm and covering 185 μm. Interval between frames: 6 mn and 30 s. cc, cardiac crescent; EHF, early head fold; ml, midline; n, node; OB, no bud; pCC, posterior cardiac crescent; pSHF, posterior second heart field. The movie can be found in S1 Movie.