Fig. 2: Pericardial progenitors have distinct migratory trajectories among heart-contributing lineages.
From: The pericardium forms as a distinct structure during heart formation
A Representative lateral (24 hpf, anterior to the left) and dorsal (18 hpf, anterior to the bottom) view of hand2:EGFP zebrafish embryos depicting embryo orientation and direction of pericardial migration as oriented in subsequent stills. N = 3 independent experiments with three embryos imaged per experiment. Arrowhead depicts the angle of 3D reconstruction in B–F. B–E Still frames of SPIM-based timelapse movie showing hand2:EGFP cell trajectories as determined by machine learning-based backtracking, anterior to the bottom. The representative stills cover development from 20–30 hpf (B), 30–40 hpf (C), 40–50 hpf (D), and 50–60 hpf (E). Arrowheads in (E) show jitter from heartbeat. F Snapshot of timelapse movie (Movies 2, 3, anterior to the bottom) showing summarized hand2:EGFP cell trajectories of the developing myocardium (left) and pericardium (right) from 20 to 60 hpf. G–J Quantification of tracked cells across replicates for myocardial and pericardial trajectories (G). Track displacement from the position start over the time series in the myocardium and pericardium (p = 0.0241). H Quantification of the speed of individual cell tracks over time (p = 0.0320). I Quantification of distance between cells (nearest neighbor) at 60 hpf (p = <0.0001). J Quantification of the number of branch points, where a single track branches into a new track indicating a cell division, in the myocardium and pericardium (p = 0.0013). G–J analyzed using Mann–Whitney t-test, N = 2 independent in toto tracking series of a single embryo from different clutches each. Each dot represents a single tracked cell analyzed per tracking experiment. Source data are provided as a Source Data file. Scale bar A 100 μm and B–F 70 μm.
