Fig. 8

Fig. 8 Migration dynamics of WT cardiac precursors versus Tbx5a-deficient embryos. A- Cell tracks of Hand2-expressing aLPM, colored by their fate at 34 hpf and laterality side of origin (White-reference point for drift correction; Green-cardiac precursors from the right; Yellow-cardiac precursors from the left; Orange-pericardial sac precursors from the right; Magenta-pericardial sac precursors from the left; Blue-pharyngeal arch precursors from the right; Cyan-pharyngeal arch precursors from the left). Background maximum-intensity projection image 20x magnification of Hand2-eGFP; H2A-mCherry embryo at 18 hpf, when time-lapse begins (Supplemental Movie 3). Merge projection is overlaid with initial positions of backtracked cells. Dorsal view, anterior to left. Scale bar- 100 ​μm. B- The degree of ballistic migration can be measured by α-value and is a factor of the speed and persistence of migration. Speed is denoted by the magnitude of individual displacement arrows and the greyscale gradient level. Persistence is the ratio of net displacement (final minus initial position, blue) and total length (distance traveled, red). C-G- Migration dynamics of cell tracks by organ precursor, comparing WT to Tbx5a MO and progenitors from the left versus the right: C- α-values, and the derivation can be seen in Fig. 9. Statistics performed using a comparison of slopes test; D- Average speed; E− Persistence F-Total track length, normalized by the number of timepoints tracked; G- Net track displacement, normalized by the number of timepoints tracked. Statistics performed using the Kruskal-Wallis rank sum test. 10 ​cells tracked per group per embryo. n ​= ​6 embryos.